Characteristics of oil displacement selection of methods. According to displacement characteristics
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Kot_86 35 6
Dec 13
Hello.
I am a student. For general development and to prepare for the course project, I want to predict the performance of the field for 5 years. I do the calculations in Excel.
As far as I understand, this (forecast of field performance for the short term) can be done using displacement characteristics.
I want you to tell me if I'm thinking in the right direction.
What is the point of the question:
There are field data (data are real; indicators from the very beginning of development (since 1976); data are given for each month until October 2013), namely: oil production, water production, water cut, cumulative oil production, cumulative water production.
Let's take one displacement characteristic (in calculations, of course, I will take several), for example, I.I. Substituting our data (in this case, cumulative oil production and cumulative water production) to calculate the logarithms. We plot the dependence of ln(Qn(t)) on ln(Ql(t). Add a trend line (linear) and an equation for the trend line to the chart. We get an equation like y=0.006*x+1.985 (for example). That is we have obtained coefficients a and b.
1) What is needed to get a forecast?
As far as I understand, it is necessary to make a forecast for Ql from the very beginning: build a graph of Ql from t, add the same trend line, get an equation of the form Ql=a+b*t. Substituting the necessary t - we get the predictive value for Qzh.
Then, when there is a forecast for the cumulative fluid production and there is an equation ln(Qn(t))=a+b*ln(Ql(t)) we easily get a forecast for the cumulative oil production.
Will this be the right decision?
2) About trend lines. It would be more correct to build a trend line from the very beginning of development or from some point in time t, where this approximation accuracy for this very trend line will be close to 1 (in the same Excel, having built a graph, you can build a trend line, display the equation of this line and here same display coefficient of approximation R^2)?
I did not find any examples / teaching aids for my work on the Internet. I just want to know if I'm doing the right thing.
P.S. I understand that much more complex tasks are being solved on this forum, but nevertheless I ask you to help in this matter. I would be very grateful for any clarification / criticism, etc.
participants
RomanK. 2161 11
For student work, I recommend setting the constant Qzh mode for the forecast. I recommend not using the logarithm of the cumulative, given the long history of development in the cumulative production of the present, it will be difficult to trace the dynamics of oil production. And here the logarithm will additionally smear. View and select any differential displacement characteristic, such as water cut from cumulative oil production (low oil viscosity up to 2 cP), logarithm of water cut from cumulative oil production at medium viscosity, and water cut from logarithm of cumulative oil production for high viscosity or log WOR from cumulative production oil. Differential characteristics require an iterative calculation, because the oil production rate depends on the water cut, and the water cut depends on the accumulated oil production. But Excel can easily handle iterative calculations. Then continue the calculation until reaching 98% water cut. Consider the economy and defense.
Antalik 1514 13 Kot_86 35 6Thank you all very much. I didn't think they would respond to me so quickly.
Today it is no longer possible to sit down for calculations. I'll definitely try tomorrow.
If I have any more questions, I'll get back to you.
Thanks again
Hello again.
There were questions about the Petroleum Office. Since I never had the opportunity to work in this program, when opening the file attached above, a question immediately arose about the notation.
Q liquad - daily fluid production
Q oil - daily oil production
WCT water cut
Q prod - oil production per year
Cum Q - cumulative oil production
RF - selection of recoverable reserves
STOIP - initial recoverable reserves
Did I understand everything correctly?
Further...Could you please explain to me these graphs (their essence). I just don't quite understand what they are for.
Another point, when using the displacement characteristics, it is logical to take not the entire development period from the bearded year, but some period preceding the forecast one with a relatively stable development system (no re-formation of the waterflooding system, no active re-drilling).
Kot_86 35 6Those. I did the right thing when I built a trend line to predict the indicator from a certain point in time t and got an approximation accuracy close to 1.
With this, it seems to be more or less clear.
Now I want to understand the Petroleum Office and make a prediction both on the differential displacement characteristic and using the method that Antalik gave me
Kot_86 - everything is correct according to the notation.
RomanK writes:
Differential characteristics require an iterative calculation, because the oil production rate depends on the water cut, and the water cut depends on the accumulated oil production. But Excel can easily handle iterative calculations.
This is what has been done. Graphs are simply dependencies of one indicator against another, given as a table of values that are used for interpolation. I just typed them in from memory.
Plot your WCT vs RF historical data on this chart and plot your trend.
With Qzh from WCT, it seems to me that I was smart, you can probably leave it constant as a first approximation.
Kot_86 35 6Thank you very much. It seems to understand everything.
Alexander 231 7you also need to remember that for a normal calculation, the forecast period should not exceed half the development history period that you took as the basis for forecasting. that is, if you take the last 10 years of history, then make a forecast for 5 years.
Gosh 1183 13alex_stan writes:
you also need to remember that for a normal calculation, the forecast period should not exceed half the development history period that you took as the basis for forecasting. that is, if you take the last 10 years of history, then make a forecast for 5 years.
Sometimes even half can be too much. But this is already a subjective choice according to the situation.
If the forecast is interval, then the interval "from to" will expand in time, then, to make a decision, you need to set the maximum allowable deviation in% from the base forecast => we get the prediction limit in time.
Well, in the absence of other more reasonable arguments, do something like a "blind test": choosing from several characteristics, as advised above, to fit the trend, take a "relatively stable" section, starting from the moment t1, and ending with the moment t2, and then do test forecast from t3 to t4, and take the characteristic that fits better with the test period of history.
Kot_86 35 6Hello. Just got my hands on a computer today. I decided to sit down again for the calculations and ... again hung up.
Again, several questions arose:
1) It was proposed to set the regime of constant Ql for the forecast. Those. constant production of fluid per year, did I understand correctly? Use this for all displacement characteristics?
2) Differential displacement characteristics. Nowhere could I find any list of differential characteristics. Could you help me?
P.S. Regarding Petroleum Office: downloaded, installed. When I tried to change/calculate something, Excel crashed. On this, for now, my acquaintance with this add-on is over :)
Kot_86 writes:
Hello. Just got my hands on a computer today. I decided to sit down again for the calculations and ... again hung up. Several questions arose again: 1) It was proposed to set the regime of constant Ql for the forecast. Those. constant production of fluid per year, did I understand correctly? Use this for all displacement characteristics? 2) Differential displacement characteristics. Nowhere could I find any list of differential characteristics. Could you help me? P.S. Regarding Petroleum Office: downloaded, installed. When I tried to change/calculate something, Excel crashed. On this, for now, my acquaintance with this add-on is over :)
1) yes
2) in fact, any characteristic of displacement in an explicit or implicit form can be represented in an integral or differential form. But in practice, when creating models for calculations, integral curves are preferred, since they are less affected by changes in the development system.
Kot_86 35 6
And again questions (I'm still just learning, I don't understand a lot (but I'm trying to improve), so I immediately apologize for maybe stupid questions):
1) Let's say Qzh is taken constant for a year. But there are displacement characteristics, where either 3 parameters are used at once (A.V. Davydov), or Qzh does not appear at all (M.I. Maksimov). In both cases, I can make a forecast for the cumulative fluid production (because Ql for the year is a constant), but I cannot predict Qv and Ql. Qн depends on Ql and Qv, and Qv depends on the water cut. How to be?
2) Using several characteristics received different indicators. End up taking the average over them?
1) if the theory is brief, then according to the existing classification, the displacement characteristics are divided into watering and dip curves. Numerous water cut curves are relationships between cumulative oil, water and/or liquid productions or relationships between cumulative production and water cut. Watering curves characterize the process of watering wells (area) depending on the accumulated fluid production. These methods cannot be used during dry oil production.
Production decline curves characterize the dependence of the current oil recovery on the time factor, as well as the relationship between the current and accumulated oil recovery. These characteristics are also intended to evaluate the effectiveness of the enhanced oil recovery technology and the stimulation technology for oil production over a certain period of decline in production over time. The decline curves characterize the change in oil production over time.
Widely known methods of displacement characteristics are divided into two and three parametric. The name of the method corresponds to the number of unknown parameters required for its implementation. To implement two-parameter methods, either the integral or the differential form is sufficient. To implement three-parameter methods, it is necessary to build both integral and differential characteristics.
I think everything is clear.
2) take the one for which the coefficient. correlations closer to 1,000.
It seems that the situation has cleared up again.
Thank you very much!
Tomorrow I will start working again.
One more small question: where can I see all the known displacement characteristics? both integral and differential.
P.S. In the calculations, I used Zhdanov's methodological manual. There are many characteristics, but the designations used in the formulas are not given anywhere.
P.S.S. Searched this forum too. I found only a link to the RD in which there are about 14 of them.
And one more thing: I counted according to 7 characteristics.
But I want to take a few more, for example, Nazarov-Sipachev Qf/Qn=a+ b*Qv. There is a forecast for Qzh. The coefficients a and b are also there. Now I don’t understand how to connect this and calculate Qn and Qv ...
The same is true for the characteristics of the displacement of the French Petroleum Institute (Qv/Qн=a+b*Qн where the forecast Ql, it turns out, does not give anything), Govorov-Ryabinin, etc.
And another question: why is it actually possible to set a constant Ql for the forecast for calculations? Those. Is this just theoretical? Is there any justification for this?
why is there. In the case of mechanized oil production, for example, with the help of UCP. Each UCP has its own characteristic - nominal flow rate or productivity (m3/day). hence Qzh=const
Kot_86 35 6I completely forgot about this. Thank you!
It remains to deal with the characteristics.
I remember as a student, too, the kursach counted by character. vyt, the truth in MathCad. Here's the catch: the forecast came out very inaccurate, due to inconsistent development indicators. It turned out that at that time, according to the old geological model, it was a single object, and now, according to drilling data, the model was refined and divided into 3 (!) Blocks. That's how it happens.
Full Chaos 875 12Another little tip: go back in time for a few years and count the characteristics at the end of that period. Thus, taking into account the subsequent history, you can check the correctness of your calculations.
Mammoth 251 11If there is a good history of development, then I would advise using the relationship between the water-oil factor and the cumulative oil production. Open Excel and
1. Make a table with columns of oil and water production for periods (preferably by months).
2. According to the values of oil and water production by months, a graph is constructed, the vertical axis of which has a logarithmic scale. The values of the water-oil factor, oil and liquid production for the period are plotted on the vertical axis, and the values of cumulative oil production are plotted on the horizontal axis.
3. On the graph of the water-oil factor curve, a stable, straight-line section is determined along which the dependence of the water-oil factor on the cumulative oil production is determined (Excel itself finds the formula):
WOR =a*EXP(b*Npt)
Where:
WOR - water-oil factor;
a,b - coefficients of the logarithmic dependence;
Npt - cumulative oil production at the time of determining the water-oil factor.
4. Based on the relationship between the water-oil factor and the cumulative oil production, the forecast oil production is determined. When the water-oil factor reaches 50, which corresponds to 98% water cut, the cumulative production will correspond to recoverable reserves. These reserves should be close to the approved recoverable reserves. If they strongly diverge from the approved recoverable reserves, then it is necessary to recalculate the reserves or revise the development system.
5. Next, you need to find a logarithmic relationship between the value of the water-oil factor and the value of recoverable reserves in a straight line. The starting point of this line will correspond to the latest actual WOR and cumulative production, and the ending point will correspond to WOR 50 and final recoverable oil reserves (stated or estimated).
6. Based on this dependence, the coefficients of the logarithmic dependence of the water-oil factor on the cumulative oil production a and b are determined and the forecast values of the water-oil factor are calculated:
WOR =a*EXP(b*Npt).
7. Knowing the forecast values of the water-oil factor, the basic oil and water production of the forecast period is calculated.
8. When fluid production changes (increase due to measures, decrease due to shutdown of flooded wells), the forecast oil production will be determined by the forecast value of WOR.
Took from the magazine "Bulletin of the Central Committee of the Kyrgyz Republic" No. 3 2013.
M = 1.0 (light oil) 
M = 10.0 (medium viscosities) 
M = 100 (high oil viscosity) 
And here is the case of my field, in which, after 90% watering, there is a "sharp decrease in oil reserves" or as analyzers write there. In this case, a good, reliable line from 20% to 80% water cut, further it makes no sense to extend. 
RomanK. writes:
I often use LN(WOR) from Qoil.
I am happy to present theoretical lines for various mobility ratios. I would not recommend using this displacement characteristic for low viscosity oils. I also do not recommend using it to determine reserves at 100% water cut.
Do you mean that LN(WOR) from Qoil should not be used to determine reserves at 100% water cut?)) so reserves at 100% water cut happily go to infinity. People cut off at 50 (like 98% water cut), but the fact that it will be straight exactly up to 98% water cut is just nothing obvious ... But people stubbornly overestimate reserves)) In absolute terms, it’s not very much, but if to compare residual recoverable reserves for a water cut of 70-80 percent, then the error in residual recoverable reserves can be 2 times ...
RomanK. 2161 11Hello, friend! By cutoff 50, you probably mean LN(49)=3.892, on my charts it's an orange dotted line. Under 100%, I really flew by, there is 99.99%. A possible error can be seen in the last graph.
If extended from 80% water cut to the orange line, this is about 14 thousand tons, although it will actually be slightly less than 12 thousand tons. More often, after all, the nature of the curve is used to judge "changes in the development or measures taken."
I want to note the tail up (fictitious reduction in reserves) for light oils
Interesting charts.
Mammoth writes:
Why does the WOR line bend upwards (reducing reserves) with a rather low (70-80%) water cut?
...
Let's extend them, well, at least to the WOR value equal to 20. The largest cumulative oil production will be at М=1. The smallest at M=100.
I also didn’t notice at first that this is not a log scale, but a really taken logarithm from the WNF)
RomanK. 2161 11mishgan 130 12Mammoth writes:
Interesting charts.
Why does the WOR line bend upwards (reducing reserves) with a rather low (70-80%) water cut? Logic (I would say, art) is different - do not let this line bend.
It seems to me that the lighter the oil, the more mobile and therefore more recoverable it is, as your charts also show. Let's mentally extend the straight section on all three graphs (M=1; M=10; M=100). Let's extend them, well, at least to the WOR value equal to 20. The largest cumulative oil production will be at М=1. The smallest at M=100.
As for reserves at 100% water cut. Maybe it makes sense to shut down all the wells that were produced and leave only those productions that correspond to the base value of WOR.
Another question is how to do it? But that's a topic for another discussion.
Roma, I was talking about something else. Forecasting in a straight line Ln(WOR) =a + b*Qn is not very physical, because at 100% water cut Ln(WOR) tends to infinity, which leads to uncertainty in recoverable reserves in principle. Artificial restrictions are introduced on Ln (WOR), such as Ln (49), but, as a rule, all this leads to an overestimation of reserves, which you show (14 according to the forecast against 12 according to the "fact"). And if we use such characteristics, then, as a rule, we are at a stage with a decent water cut. For example, being at a point with a water cut of 75% (Ln(WOR)=1.1, Qн=9 t.t) and having residual recoverable reserves (12-9=3 t.t), the forecast using a linear relationship will show residual reserves 14-9=5 t.t. Such a stupid mistake...
Dima1234 253 12I use the logarithm of the WOR from the accumulated oil, and the accumulated oil from the accumulated liquid.
If Vn from Vzh can be described by a logarithm (Sazonov turns out), then I calculate the NCD using the formula. If it is impossible - I consider by hands in Excel.
mishgan writes:
Roma, I was talking about something else. Forecasting in a straight line Ln(WOR) =a + b*Qn is not very physical, because at 100% water cut Ln(WOR) tends to infinity, which leads to uncertainty in recoverable reserves in principle. Artificial restrictions are introduced on Ln (WOR), such as Ln (49), but, as a rule, all this leads to an overestimation of reserves, which you show (14 according to the forecast against 12 according to the "fact"). And if we use such characteristics, then, as a rule, we are at a stage with a decent water cut. For example, being at a point with a water cut of 75% (Ln(WOR)=1.1, Qн=9 t.t) and having residual recoverable reserves (12-9=3 t.t), the forecast using a linear relationship will show residual reserves 14-9=5 t.t. Such a stupid mistake...
I understand. Indeed, if we evaluate the "residual reserves" at high water cut, this damned tail can increase reserves uncontrollably (multiple, why not?). Good point.
mishgan 130 12Mammoth writes:
In this topic, we are talking about forecasting development indicators. My main idea is that I propose to predict production levels strictly according to the forecast value of WOR (with a given volume of fluid production), following a direct path to recoverable reserves (but this does not mean that there are no other methods).
RomanK. writes:
Mammoth writes:
Interesting charts.
Why does the WOR line bend upwards (reducing reserves) with a rather low (70-80%) water cut? Logic (I would say, art) is different - do not let this line bend.
It seems to me that the lighter the oil, the more mobile and therefore more recoverable it is, as your charts also show. Let's mentally extend the straight section on all three graphs (M=1; M=10; M=100). Let's extend them, well, at least to the WOR value equal to 20. The largest cumulative oil production will be at М=1. The smallest at M=100.
As for reserves at 100% water cut. Maybe it makes sense to shut down all the wells that were produced and leave only those productions that correspond to the base value of WOR.
In this topic, we are talking about forecasting development indicators. My main idea is that I propose to predict production levels strictly according to the forecast value of WOR (with a given volume of fluid production), following a direct path to recoverable reserves (but this does not mean that there are no other methods). Another question is how to do it? But that's a topic for another conversation.I will disappoint you a little, the reserves in all graphs are the same = 12 thousand tons, I didn’t reach all the options to 99% water cut, but I can do it (I illustrated something different, and for illustration this is a complete picture). So no matter how you extend it, it is physically impossible to extract more than 12 thousand tons. Just like daylight - no oil. Therefore, it is not worth extending something and inventing stocks that are not there. Mishgen is right, all these graphs will asymptotically approach the number 12, but never cross it.
Why is LN(WNF) not a line? Why does it have to be a line? I have shown synthetic curves, from which it is clear which intervals can be taken as linear and which are not.
You have already tried to describe the basic WNF values - it is really very difficult to understand what you mean.
And your proposal for predicting development indicators and the question of how to do it.
Well, as if outside the window of 2014, everything has already been invented before us. Actually, my illustrations are the echoes of already implemented, tested and successfully forgotten analytical forecasting.
We are talking about different vegetables. Thanks Mishgen. Your phrase “I often use LN (WOR) from Qoil” has nothing to do with the characteristic I am talking about. Try to make a graph with a logarithmic scale on the vertical axis and normal scale on the horizontal axis. On the vertical axis, plot WOR values (not the logarithm of WOR), and on the horizontal axis, plot cumulative oil production. You will get something terrible or a fairly straight line (depending on the quality of the incoming information). Find a stable area on this line and the formula of this line. However, I wrote all this above. How to insert a chart?
RomanK. 2161 11
Mishgen, you can immediately see an experienced person. Completely agree with you.
The illustrations I have shown show the displacement characteristic for one, closed element (development area). In reality, the final displacement characteristic is the sum of the displacement characteristics, if, for example, we decompose the final HB, we can see the components into its constituent parts.
For example, I analyzed drilling by year and the resulting displacement characteristic on a log scale was linear, leading to the conclusion that drilling did not increase recoverable reserves. Further, dividing the drilling by years, i.e. Having carried out the decomposition, it is clearly seen that the line in the logarithm is a consequence of the introduction of new reserves. In the year the drilling was completed, the line ceased to exist, which is interpreted as "everything is gone."
Although it is not.
mishgan writes:
Mammoth writes:
In this topic, we are talking about forecasting development indicators. My main idea is that I propose to predict production levels strictly according to the forecast value of WOR (with a given volume of fluid production), following a direct path to recoverable reserves (but this does not mean that there are no other methods).You stubbornly assert that there should be a line there... Moreover, at least up to Ln(49). Well, then to predict the matter of technology ...
Being engaged in production forecasting, I also saw many fields with a linear behavior of Ln(WOR) from Qn. And this does not in the least contradict the fact that the real characteristic is bent upwards. This is very easy to explain. Simplistically, the total production is made up of production from "basic wells" (without well interventions), the total characteristic of which behaves as described by Roman + production from well interventions (mainly refers to well interventions with reserves growth), which constantly does not allow this characteristic to bend upwards, t .e maintains its "straightness".
Hence, it seems that the field will continue to follow this straight line. But this is erroneous due to the fact that at a certain moment the geological and technical measures will end with an increase in reserves and the characteristic will still bend upwards. Therefore, the forecast must be kept separately for production from the base + and separately for production from geological and technical measures. And just imposing a straight line on the displacement characteristic is akin to a lottery
GTM has nothing to do with it. Knowing the basic WOR, one can easily determine oil production with a given volume of liquid. GTM is an additional volume of fluid (and it is not a fact that the money spent on GTM went in favor). RomanK. 2161 11
Mammoth writes:
“I often use LN (VNF) from Qoil” has nothing to do with the characteristic I am talking about. Try to make a graph with a logarithmic scale on the vertical axis and normal scale on the horizontal axis. On the vertical axis, plot WOR values (not the logarithm of WOR), and on the horizontal axis, plot cumulative oil production.
What year and what university did you graduate from?
Mammoth 251 11 Well, on this, perhaps, we will interrupt. Very beautiful graphics, you can not argue. I don’t get these, even when the water cut reaches 95%. We agree with such a specialist that when the water cut reaches 70%, we close the field.
RomanK. 2161 11Why are you on your own and why are we closing the deposit?
Nobody said that, it's your fantasy.
I understood Mammoth like this (picture). 
In my opinion, it is sensible to use such an XB for operational management of development. Simple and clear.
Damn, how do I post pictures?
RomanK. 2161 11DimA1234 writes:
In my opinion, it is sensible to use such an XB for operational management of development. Simple and clear.
Actually, this is how it has been used for a century already :)
And there is one more note, the use of displacement characteristics assumes 100% compensation. This has been forgotten by many. For example, you can stop pumping water and start reducing water cut - this will cause a fictitious increase in reserves, while oil will be taken from the elastic reserve. This is the secret of the effectiveness of cyclic waterflooding, when, with all the efficiency, long-term trends can show a zero effect.
Are you kidding or serious? building a WNF on a Log scale or building a Ln(WNF) on a linear scale is the same thing, whichever is more convenient for you ...
Mammoth writes:
GTM is an additional volume of liquid (and it’s not a fact that the money spent on GTM went in favor)
respecting your age and experience, let me comment that geological and technical measures in the modern world of the oil industry are not only the stimulation measures that you describe. What was mentioned above referred to those geological and technical measures that increase reserves. That is, mainly drilling and sidetracking. They just straighten the characterization. As soon as we stop incrementing reserves (commissioning wells with lower water cut), we will have to forget about linearity. I do not know how to convey this simple idea even more clearly.
Here is what you are saying.
We have a field, production in dynamics consists of 1) base production together with well interventions for stimulation + 2) production from the commissioning of new wells and sidetracking (well interventions with reserves increment). Having plotted the CW based on it, you see a linear section and, voila, you predict production ahead of it for any given fluid withdrawals. Let's say. But do you notice that you call this prey BASIC?! Those. Do you think that this trend is basic, and such well interventions as drilling and sidetracking will only add reserves above this trend? If so, then I'm sorry, I'm not on the way with you :) AlNikS 872 11
RomanK. writes:
For example, I analyzed drilling by year and the resulting displacement characteristic on a log scale was linear, leading to the conclusion that drilling did not increase recoverable reserves. Further, dividing the drilling by years, i.e. Having carried out the decomposition, it is clearly seen that the line in the logarithm is a consequence of the introduction of new reserves. In the year the drilling was completed, the line ceased to exist, which is interpreted as "everything is gone."
To be honest, in my opinion, analyzing DRILLING using displacement characteristics is some kind of nonsense ... Unless you are going to develop a field, evenly drilling N wells per year throughout the development period.
Mammoth 251 11He was inattentive and gave reason to gloat wise men. Himself to blame.
DimA1234, You are absolutely right. Only the phrase “Everything is fine, we are entering the NOR with less water cut” I would replace with the phrase “Everything is fine, we are involving unaccounted reserves in the development and increasing oil recovery (OR)”. In other words, inventories were understated.
It doesn't reach RomanK and mishgan. However, RomanK. utters the clever phrase "Actually, it's been used like this for a century." Maybe in the West, yes, we still do not apply this everywhere.
The chart presented by RomanK should be divided into two parts - history and forecast.
RomanK, show on the graph the formula for the relationship between WOR and cumulative oil production for a straight section of history. Using this formula, find the WOR value for the next, after the actual, period for any (real) volume of liquid. This value will be the base value of the WNF. In other words, determine which of the two wells needs to be repaired, the one that, after repair, will produce 300 m3 of water and 20 tons of oil, or the one that, after repair, will produce 80 m3 of water and 10 tons of oil. I do not know yet. Because I don't know the base value of WNF. When you know the base WOR value, you will repair the well, the WOR value of which is closer to the base WOR value.
Mishgan, I'm not talking about base loot at all. I'm talking about the base value of WNF. You mentioned the word "intensification". What is intensification? Don't think that I don't know. I want to know if you know this or not? What is the difference between intensification and optimization? Wasteland Rat writes:
To be honest, in my opinion, analyzing DRILLING using displacement characteristics is some kind of nonsense ... Unless you are going to develop a field, evenly drilling N wells per year throughout the development period.
Rats, what exactly is crazy? The task of commissioning new wells is to increase potential reserves, you want to name the oil recovery factor. For example, as a virtual owner, it would be interesting for me to see how a multiple increase in the fund affected the reserves - whether there was a significant increase or like tubes in one bucket, without an increase. Grandmas measure for years, so it is logical to keep wells for years. If you counted the eight - the point of production from new wells, then it's easy to keep new wells and further over the years. You can even notice how new wells, like Cinderella, on the night of December 31 to January 1, lose their "achieved and overfulfilled oil production rate", for which a premium has already been accrued.
Mishgan, I also responsibly declare to you that no geological and technical measures increase reserves. The reserves of hydrocarbons were made by our mother Earth and many thanks to her for this. And people count the reserves, then recalculate and, make an increase in reserves, and then recalculate again and, again increase the reserves. It also happens vice versa. It depends on who is studying. And the wells in which these or those geological and technical measures are made extract these reserves. And each well (GTM) has its own potential, more than which it cannot give. After calculating the reserves and evaluating the oil recovery factor, people place (design) wells on deposits, drill and put them into operation. Some wells are introduced for the purpose of fluid withdrawal, others for the purpose of compensating for fluid withdrawal.
And so, if the calculation of reserves and oil recovery factors are calculated correctly, the development system is compiled correctly, wells (and the deposit as a whole) are operated at all stages of development in accordance with their potential and maintaining the material balance, then in the end all calculated recoverable reserves will be selected from the deposit when water cut reaches 98% or WOR value =50. Development in this case will follow a direct relationship between WOR and cumulative production, the coordinates of the last point of which will have the values 50:LOW.
This, as a rule, does not happen. It happens when wells are either under-produced or re-produced (not to be confused with well potential). When wells are not producing enough reserves, the straight line is more vertical and it is necessary to carry out work to optimize the development, i.e. direct the graph line to the end point at coordinates 50: BOTTOM. If the wells are re-producing reserves, then the straight line is more horizontal. This means that the wells will extract more than it is envisaged by the project. We conclude that the reserves are estimated to be underestimated, and the competent development of wells (with their various well interventions) led to an increase in oil recovery. It also happens when the development goes in a straight line with the coordinates of the last point 50: BOTTOM, but the development period is very long. With certain geological and technical measures, the development period can be reduced by staying on this line. Such geological and technical actions will lead to the intensification of development. To determine in which of the three cases the reservoir will be located in the forecast period, it is necessary to know the base value of the WOR.
RomanK, in order to notice how new wells, like Cinderellas, on the night of December 31 to January 1, lose their "achieved and overfulfilled oil production rate", for which a premium has already been accrued (by the way, not only new ones), you need to keep a daily summary of production, delivery and the presence of oil in the park and the injection of commercial water, and not to give everything at the mercy of the preparers. And to confuse this summary with the monthly geological reporting.
4.3 Displacement characteristics
The use of displacement characteristics (CV) in solving the problems of developing oil deposits was first proposed by D.A. Efros (1959) in the form of a dependence of the cumulative oil recovery on the cumulative fluid recovery.
The advantages of the forecasting method based on the use of the characteristics of oil displacement by water are:
Ease of application of this forecasting method;
Recoverable oil reserves are determined by the displacement characteristics directly, without a preliminary value of the balance reserves and the design oil recovery factor, the determination of which in some cases is difficult.
The essence of the technique is as follows.
A widely used method for solving this problem is the least squares method. Let's consider a specific case. The system of equations is given:
System of two linear equations with two unknowns a, b. Further, from the second equality, expressing the coefficient b, and substituting into the first equality, we find the coefficient a. The actual values of the function are determined by substituting the actual value of the cumulative production of products (V n, V c, V l) into the left side of the equations.
The success of the use of displacement characteristics in determining the technological effect of BGS and intensification of oil inflow is primarily due to the fact that such coordinate systems are selected in which the data fit more or less well on a straight line.
When using the displacement characteristics, there is a fairly high probability that if the actual points lie closely enough on the straight line on the prehistory period, then on the extrapolation period they will also lie on the straight line.
Displacement characteristics used to select the equation of the watering curve for evaluating the efficiency of EOR.
where Q n, Q n, Q l - the actual values of the cumulative production of oil, water, liquid; a, b are constant coefficients.
To determine oil production through the use of HW according to CW, dependencies are plotted in coordinates. Then additional production is determined. The results of oil production calculations and the calculation of the base curves were made using a computer (using the Microsoft Excel program).
Let us consider the Maksimov method in more detail using the example of well No. 1
(4.3.9)
(4.3.10)
Theil criterion:
(4.3.11)
Table 4.3.1 Results of calculating oil production due to EOR (well No. 1)
| DATE | Production per month, t. | The cumulative production, | ||
| Oil | Water | Oil | Liquid | |
| 07.08 | 345 | 9265 | 345 | 9610 |
| 08.08 | 268 | 9245 | 613 | 19123 |
| 09.08 | 257 | 8600 | 870 | 27980 |
| 10.08 | 249 | 7669 | 1119 | 35898 |
| 11.08 | 276 | 10604 | 1395 | 46778 |
| 12.08 | 286 | 10887 | 1681 | 57951 |
| 01.09 | 323 | 7956 | 2004 | 66230 |
| 02.09 | 281 | 7688 | 2285 | 74199 |
| 03.09 | 321 | 8941 | 2606 | 83461 |
| 04.09 | 354 | 8583 | 2960 | 92398 |
| 05.09 | 363 | 8837 | 3323 | 101598 |
| 06.09 | 319 | 8487 | 3642 | 110404 |
| 07.09 | 371 | 8670 | 4013 | 119445 |
| 08.09 | 359 | 8569 | 4372 | 128373 |
| 09.09 | 336 | 8963 | 4708 | 137672 |
| 10.09 | 264 | 8863 | 4972 | 146799 |
| 11.09 | 255 | 10203 | 5227 | 157257 |
| 12.09 | 218 | 10463 | 5445 | 167938 |
Table 4.3.2 Calculated base curves
| date | Abyzbaev | Govorov-Ryabinin | Davydov | Kambarov | Maksimov | Fast. Neftesod. | Sazonov |
| 07.08 | 5,763 | 9,2281 | 1754,28 | 5859,24 | -304,07 | 248,52 | -302,29 |
| 08.08 | 6,430 | 9,8180 | 1887,40 | 4301,66 | 626,30 | 558,09 | 624,50 |
| 09.08 | 6,800 | 10,1774 | 1920,71 | 3803,58 | 1139,28 | 846,32 | 1137,13 |
| 10.08 | 7,042 | 10,4357 | 1918,01 | 3566,38 | 1474,17 | 1103,98 | 1472,77 |
| 11.08 | 7,298 | 10,6620 | 1964,75 | 3371,43 | 1831,93 | 1458,04 | 1829,34 |
| 12.08 | 7,506 | 10,8534 | 1992,95 | 3247,41 | 2121,00 | 1821,64 | 2117,83 |
| 01.09 | 7,636 | 11,0338 | 1949,64 | 3182,51 | 2298,78 | 2091,05 | 2297,69 |
| 02.09 | 7,746 | 11,1685 | 1931,03 | 3133,71 | 2450,78 | 2350,38 | 2450,72 |
| 03.09 | 7,860 | 11,3034 | 1916,19 | 3088,71 | 2608,31 | 2651,79 | 2609,15 |
| 04.09 | 7,959 | 11,4341 | 1888,10 | 3053,84 | 2743,94 | 2942,62 | 2746,17 |
| 05.09 | 8,051 | 11,5529 | 1864,83 | 3024,35 | 2870,61 | 3242,00 | 2874,02 |
| 06.09 | 8,132 | 11,6469 | 1855,12 | 3000,73 | 2981,96 | 3528,57 | 2985,97 |
| 07.09 | 8,208 | 11,7465 | 1834,03 | 2980,10 | 3086,93 | 3822,78 | 3091,99 |
| 08.09 | 8,278 | 11,8344 | 1818,10 | 2962,58 | 3183,19 | 4113,32 | 3189,08 |
| 09.09 | 8,346 | 11,9104 | 1813,24 | 2946,75 | 3277,01 | 4415,93 | 3283,27 |
| 10.09 | 8,408 | 11,9664 | 1824,59 | 2933,16 | 3363,76 | 4712,94 | 3369,73 |
| 11.09 | 8,475 | 12,0178 | 1846,44 | 2919,53 | 3457,15 | 5053,27 | 3462,42 |
| 12.09 | 8,539 | 12,0597 | 1874,69 | 2907,36 | 3546,63 | 5400,85 | 3550,93 |
| Coeff. A | -3,13684 | 3,230525 | -31628,6 | 2728,19 | -12583,2 | -64,2134 | -12654,2 |
| Coeff. B | 0,970435 | 1,026355 | 34626 | -30089419 | 1344,335 | 0,032542 | 1346,908 |
| Theil criterion | 0,017256 | 0,007321 | 0,02051 | 0,014113 | 0,044377 | 0,010731 | 0,044397 |
Table 4.3.3
| date | Kambarov's formula | Govorov-Ryabinin formula | Formula Post. Neftesod. | Average value | |||||||
| ext. oil, t | additional production | ext. oil, t | additional production | ext. oil, t | additional production | additional production | |||||
| per month | accumulated | per month | accumulated | per month | accumulative | per month | accumulative | ||||
| 07.09 | 2980,10 | 1032,9 | 1032,9 | 3675,87 | 337,12 | 337,12 | 3822,78 | 190,21 | 190,21 | 520,08 | 520,08 |
| 08.09 | 2962,58 | 1409,42 | 2442,32 | 3941,49 | 430,50 | 767,63 | 4113,32 | 258,67 | 448,89 | 699,53 | 1219,61 |
| 09.09 | 2946,75 | 1761,25 | 4203,57 | 4218,82 | 489,17 | 1256,8 | 4415,93 | 292,07 | 740,96 | 847,49 | 2067,11 |
| 10.09 | 2933,16 | 2038,84 | 6242,41 | 4492,58 | 479,41 | 1736,22 | 4712,94 | 259,05 | 1000,02 | 925,77 | 2992,88 |
| 11.09 | 2919,53 | 2307,47 | 8549,88 | 4807,2 | 419,79 | 2156,02 | 5053,27 | 173,73 | 1173,75 | 967,00 | 3959,88 |
| 12.09 | 2907,36 | 2537,64 | 11087,52 | 5129,26 | 315,73 | 2471,75 | 5400,85 | 44,14 | 1217,90 | 965,84 | 4925,72 |
Rice. 4.3.1. Dependence of cumulative oil production on cumulative liquid production (Kambarov method)
Rice. 4.3.2. Dependence of cumulative oil production on cumulative fluid production (Govorov-Ryabinin method)
Rice. 4.3.3. Dependence of cumulative oil production on cumulative fluid production (constant oil content method)
Rice. 4.3.4. Schedule for calculating additional oil production due to EOR (well No. 1)
Calculation data for wells No. 2, No. 3 are given in tables 4.3.4 - 4.3.9.
Table 4.3.4 Results of calculating oil production due to EOR well No. 2
| DATE | Production per month, t. | The cumulative production, | ||
| Oil | Water | Oil | Liquid | |
| 02.08 | 358 | 1436 | 358 | 1794 |
| 03.08 | 409 | 1622 | 767 | 3825 |
| 04.08 | 395 | 1463 | 1162 | 5683 |
| 05.08 | 433 | 1385 | 1595 | 7501 |
| 06.08 | 385 | 1365 | 1980 | 9251 |
| 07.08 | 432 | 1557 | 2412 | 11240 |
| 08.08 | 435 | 1598 | 2847 | 13273 |
| 09.08 | 635 | 1077 | 3482 | 14985 |
| 10.08 | 590 | 1035 | 4072 | 16610 |
| 11.08 | 347 | 1385 | 4419 | 18342 |
| 12.08 | 352 | 1465 | 4771 | 20159 |
| 01.09 | 501 | 1135 | 5272 | 21795 |
| 02.09 | 461 | 1159 | 5733 | 23415 |
| 03.09 | 440 | 1335 | 6173 | 25190 |
| 04.09 | 413 | 1315 | 6586 | 26918 |
| 05.09 | 487 | 1254 | 7073 | 28659 |
| 6.09 | 429 | 1105 | 7502 | 30193 |
| 07.09 | 486 | 1123 | 7988 | 31802 |
| 08.09 | 545 | 1163 | 8533 | 33510 |
| 09.09 | 645 | 1569 | 9178 | 35724 |
| 10.09 | 359 | 948 | 9537 | 37031 |
| 11.09 | 469 | 1257 | 10006 | 38757 |
Table 4.3.5 Calculated base curves
| date | Abyzbaev | Govorov-Ryabinin | Davydov | Kambarov | Maksimov | Fast. Neftesod. | Sazonov |
| 02.08 | 5,823793 | 7,340 | 492,605 | 11486,28 | -1343,38 | 163,55 | -1316,65 |
| 03.08 | 6,652752 | 8,016 | 603,0457 | 8042,717 | 642,4696 | 681,47 | 625,45 |
| 04.08 | 7,086245 | 8,385 | 1052,944 | 7048,254 | 1669,607 | 1155,28 | 1641,047 |
| 05.08 | 7,390142 | 8,666 | 1984,165 | 6552,063 | 2371,672 | 1618,88 | 2353,024 |
| 06.08 | 7,619737 | 8,857 | 2142,916 | 6258,648 | 2917,92 | 2065,14 | 2890,924 |
| 07.08 | 7,832965 | 9,032 | 2206,735 | 6036,096 | 3427,676 | 2572,35 | 3390,481 |
| 08.08 | 8,014996 | 9,179 | 2195,888 | 5877,55 | 3864,764 | 3090,78 | 3816,945 |
| 09.08 | 8,147826 | 9,358 | 4233,019 | 5777,405 | 4123,025 | 3527,35 | 4128,144 |
| 10.08 | 8,260552 | 9,497 | 5690,788 | 5701,446 | 4349,369 | 3941,73 | 4392,24 |
| 11.08 | 8,369153 | 9,569 | 5208,462 | 5635,303 | 4624,636 | 4383,40 | 4646,674 |
| 12.08 | 8,472574 | 9,637 | 4723,522 | 5578,13 | 4887,47 | 4846,75 | 4888,971 |
| 01.09 | 8,558009 | 9,726 | 5318,796 | 5534,808 | 5074,431 | 5263,94 | 5089,13 |
| 02.09 | 8,636509 | 9,800 | 5655,395 | 5497,875 | 5252,535 | 5677,05 | 5273,041 |
| 03.09 | 8,716514 | 9,866 | 5679,849 | 5462,862 | 5443,754 | 6129,69 | 5460,478 |
| 04.09 | 8,789158 | 9,923 | 5635,553 | 5433,212 | 5619,412 | 6570,34 | 5630,671 |
| 05.09 | 8,857778 | 9,987 | 5878,317 | 5406,955 | 5776,643 | 7014,31 | 5791,435 |
| 6.09 | 8,914869 | 10,039 | 6068,648 | 5386,329 | 5907,799 | 7405,49 | 5925,189 |
| 07.09 | 8,971715 | 10,094 | 6377,691 | 5366,833 | 6034,703 | 7815,79 | 6058,369 |
| 08.09 | 9,028994 | 10,153 | 6772,26 | 5348,186 | 6159,97 | 8251,34 | 6192,564 |
| 09.09 | 9,099044 | 10,218 | 7031,456 | 5326,668 | 6320,025 | 8815,93 | 6356,68 |
| 10.09 | 9,138387 | 10,252 | 7102,916 | 5315,174 | 6412,208 | 9149,22 | 6448,853 |
| 11.09 | 9,188266 | 10,294 | 7174,932 | 5301,182 | 6529,653 | 9589,36 | 6565,711 |
| Coeff. A | -2,37941 | 2,125022 | 91740,72 | 5000,988 | -20441,7 | -293,927 | -20535,3 |
| Coeff. B | 1,094898 | 0,886903 | -113997 | -11634616 | 2627,138 | 0,255007 | 2565,153 |
| Theil criterion | 0,014237 | 0,010871 | 0,060408 | 0,016605 | 0,027179 | 0,028408 | 0,027169 |
Table 4.3.6
| date | Kambarov's formula | Govorov-Ryabinin formula | Abyzbaev's formula | Average value | |||||||
| ext. oil, t | additional production | ext. oil, t | additional production | ext. oil, t | additional production | additional production | |||||
| per month | accumulated | per month | accumulated | per month | accumulated | per month | accumulated | ||||
| 06.09 | 5386,32 | 2115,67 | 2115,67 | 7425,67 | 76,32 | 76,32 | 7441,8 | 60,19 | 60,19 | 750,73 | 750,73 |
| 07.09 | 5366,83 | 2621,16 | 4736,83 | 7841,32 | 146,67 | 223,001 | 7877,09 | 110,90 | 171,09 | 959,58 | 1710,31 |
| 08.09 | 5348,18 | 3184,81 | 7921,65 | 8274,43 | 258,56 | 481,56 | 8341,46 | 191,53 | 362,63 | 1211,6 | 2921,95 |
| 09.09 | 5326,66 | 3851,33 | 11772,98 | 8862,80 | 315,19 | 796,76 | 8946,73 | 231,26 | 593,89 | 1465,9 | 4387,88 |
| 10.09 | 5315,17 | 4221,82 | 15994,81 | 9220,47 | 316,53 | 1113,29 | 9305,74 | 231,25 | 825,15 | 1589,8 | 5977,75 |
| 11.09 | 5301,18 | 4704,81 | 20699,62 | 9697,14 | 308,85 | 1422,15 | 9781,67 | 224,32 | 1049,47 | 1745,9 | 7723,75 |
Rice. 4.3.5. Dependence of cumulative oil production on cumulative liquid production (Kambarov method)
Rice. 4.3.6. Dependence of cumulative oil production on cumulative fluid production (Govorov-Ryabinin method)
Rice. 4.3.7. Dependence of cumulative oil production on cumulative fluid production (Abyzbaev's method)
Rice. 4.3.8. Schedule for calculating additional oil production due to EOR (well No. 2)
Table 4.3.7 Results of calculating oil production due to EOR well No. 3
| DATE | Production per month, t. | The cumulative production, | ||
| Oil | Water | Oil | Liquid | |
| 10.08 | 546 | 496 | 546 | 1042 |
| 11.08 | 600 | 561 | 1146 | 3245 |
| 12.08 | 727 | 1322 | 1873 | 7497 |
| 01.09 | 625 | 1006 | 2498 | 13380 |
| 02.09 | 625 | 977 | 3123 | 20865 |
| 03.09 | 718 | 1106 | 3841 | 30174 |
| 04.09 | 653 | 995 | 4494 | 41131 |
| 05.09 | 651 | 1065 | 5145 | 53804 |
| 06.09 | 609 | 1004 | 5754 | 68090 |
| 07.09 | 679 | 1146 | 6433 | 84201 |
| 08.09 | 613 | 1068 | 7046 | 101993 |
| 09.09 | 709 | 1063 | 7755 | 121557 |
| 10.09 | 670 | 1125 | 8425 | 142916 |
| 11.09 | 666 | 1048 | 9091 | 165989 |
Table 4.3.8 Calculated base curves
| date | Abyzbaev | Govorov-Ryabinin | Davydov | Kambarov | Maxi-mov | Fast. Neftesod. | Sazonov |
| 10.08 | 6,367073 | 6,173217 | -145,871 | 7219,934 | -4,74 | 1139,46 | -0,21865 |
| 11.08 | 7,004604 | 7,096609 | 1902,251 | 4755,44 | 1213,02 | 1322,82 | 1310,575 |
| 12.08 | 7,474564 | 7,708453 | 2016,803 | 4094,31 | 2518,71 | 1676,722 | 2276,833 |
| 01.09 | 7,799656 | 8,067078 | 2893,663 | 3872,465 | 3086,34 | 2166,375 | 2945,236 |
| 02.09 | 8,049013 | 8,345191 | 3492,406 | 3771,047 | 3494,47 | 2789,366 | 3457,926 |
| 03.09 | 8,256051 | 8,602922 | 3871,876 | 3715,117 | 3858,18 | 3564,172 | 3883,606 |
| 04.09 | 8,429907 | 8,79847 | 4200,112 | 3681,722 | 4127,26 | 4476,144 | 4241,061 |
| 05.09 | 8,580643 | 8,966957 | 4434,762 | 3660,06 | 4372,76 | 5530,942 | 4550,981 |
| 06.09 | 8,712801 | 9,106285 | 4633,89 | 3645,31 | 4574,26 | 6719,993 | 4822,703 |
| 07.09 | 8,831991 | 9,24521 | 4775,162 | 3634,68 | 4777,11 | 8060,942 | 5067,763 |
| 08.09 | 8,939575 | 9,358569 | 4905,716 | 3626,843 | 4945,59 | 9541,804 | 5288,962 |
| 09.09 | 9,038058 | 9,47798 | 5017,643 | 3620,874 | 5097,41 | 11170,15 | 5491,447 |
| 10.09 | 9,128905 | 9,581185 | 5108,237 | 3616,224 | 5243,87 | 12947,9 | 5678,232 |
| 11.09 | 9,2129 | 9,67594 | 5193,64 | 3612,545 | 5369,26 | 14868,31 | 5850,929 |
| Coeff. A | 2,467206 | -1,67636 | 6341,679 | 3589,756 | -9994,16 | 1052,732 | -8018,52 |
| Coeff. B | 0,561221 | 1,245447 | -13629,1 | -3782645 | 1609,489 | 0,083232 | 1153,895 |
| Theil criterion | 0,007578 | 0,012871 | 0,049668 | 0,005903 | 1,522027 | 0,004238 | 26,16246 |
Table 4.3.9
| date | Kambarov's formula | Abyzbaev's formula | Formula Post. Neftesod. | Average value | |||||||
| accumulated ext. oil, t | additional production | accumulated ext. oil, t | additional production | accumulated ext. oil, t | additional production | additional production | |||||
| per month | accumulated | per month | accumulated | per month | accumulated | per month | accumulated | ||||
| 07.09 | 3645,31 | 2108,69 | 2108,69 | 6080,25 | -326,25 | -326,25 | 6719,99 | -965,99 | -965,99 | 272,15 | 272,15 |
| 08.09 | 3634,68 | 2798,32 | 4907,01 | 6849,91 | -416,91 | -743,16 | 8060,94 | -1627,94 | -2593,93 | 251,16 | 523,31 |
| 09.09 | 3626,84 | 3419,16 | 8326,17 | 7627,96 | -581,96 | -1325,12 | 9541,80 | -2495,80 | -5089,74 | 113,80 | 637,10 |
| 10.09 | 3620,87 | 4134,13 | 12460,29 | 8417,41 | -662,41 | -1987,53 | 11170,15 | -3415,15 | -8504,89 | 18,85 | 655,96 |
| 11.09 | 3616,22 | 4808,78 | 17269,07 | 9217,92 | -792,92 | -2780,45 | 12947,90 | -4522,90 | -13027,79 | -169,02 | 486,94 |
| 12.09 | 3612,54 | 5478,46 | 22747,52 | 10025,63 | -934,63 | -3715,08 | 14868,31 | -5777,31 | -18805,11 | -411,16 | 75,78 |
Rice. 4.3.9. Dependence of cumulative oil production on cumulative fluid production (Kambarov method)
Rice. 4.3.10. Dependence of cumulative oil production on cumulative fluid production (Abyzbaev's method)
Rice. 4.3.11. Dependence of cumulative oil production on cumulative fluid production (constant oil content method)
Rice. 4.3.12. Schedule for calculating additional oil production due to EOR (well No. 3)
5. CALCULATION OF TECHNOLOGICAL INDICATORS OF DEVELOPMENT WHEN APPLYING THE METHOD
Calculation of development indicators according to the method of current planning of oil and liquid production. This technique is known as the "Methodology of the State Planning Committee of the USSR". It is still used in all oil and gas production departments, in oil producing companies, in organizations of the fuel and energy complex and in planning organizations.
Initial data for calculation:
1. Initial balance oil reserves (NBZ), t;
2. Initial recoverable oil reserves (NIR), t;
3. At the beginning of the planned year:
Cumulative oil production (ΣQ n), t;
Cumulative fluid production (ΣQ l), t;
Cumulative water injection (ΣQ zak), m 3 ;
The operating stock of producing wells (N d days);
Operating stock of injection wells (N days);
4. Dynamics of well drilling by years for the planned period (Nb):
Mining (N d b);
Injection (N n b).
Table 5.1 Initial data for the Zapadno-Leninogorskaya area of the Romashkinskoye field
| Year | NBZ, thousand tons | NCD, thousand tons | ΣQ n, thousand tons | ΣQ w, thousand tons | ΣQ order, thousand m 3 | ||||
| 2009 | 138322 | 69990 | 54830 | 200323 | 236577 | 307 | 196 | 3 | 1 |
Calculation of development indicators
1. Number of days of operation of production wells in a year, transferred from the previous year:
D lane \u003d 365 × K (5.1)
D lane \u003d 365 × 0.9 \u003d 328.5
2. Number of days of operation of new production wells:
3. Average oil production rate of new producing wells:
q n new = 8 t/day
4. The coefficient of decline in oil production of producing wells:
5. Annual oil production from new wells:
(5.1)
6. Annual oil production from transferred wells:
7. Annual oil production total
(5.3)
8. Annual oil production from new wells of the previous year, if they worked without falling in this year:
9. Annual oil production from the transferred wells of the previous year (if they worked without falling):
10. Possible estimated oil production from all wells of the previous year (if they work without falling):
(5.5)
11. Planned oil production from wells of the previous year:
12. Decrease in oil production from wells of the previous year:
(5.6)
13. Percentage of change in oil production from wells of the previous year:
(5.7)
14. Average production rate of one well for oil:
(5.8)
15. Average production rate of wells for oil transferred from the previous year:
(5.9)
16. Cumulative oil production:
17. The current oil recovery factor (ORF) is inversely proportional to the initial balance reserves (NBZ):
(5.11)
18. Withdrawal from approved initial recoverable NCD reserves, %:
(5.12)
19. Recovery rate from initial recoverable reserves (NIR), %:
(5.13)
20. Recovery rate from current recoverable reserves, %:
(5.14)
21. Average water cut of produced products:
(5.15), 
22. Annual liquid production:
23. Liquid production since the beginning of development:
24. Annual water injection:
(5.18)
25. Annual compensation for liquid withdrawal by injection:
26. Cumulative compensation of liquid withdrawal by injection:
27. Water-oil factor:
The dynamics of the main development indicators is shown in Table. 5.2
Table 5.2 Dynamics of the main development indicators
| years | Production, million tons | Cumulative production, million tons | IN, % | Water injection, million m 3 | Average oil production rate, t/day | CIN | Rate of selection from NIH | The rate of selection from TIZ | |||
| oil | liquids | oil | liquids | year | S | ||||||
| 2010 | 0,462 | 10,286 | 55,292 | 311,764 | 0,96 | 13,840 | 250,417 | 4,22 | 39,97 | 1,23 | 1,46 |
| 2011 | 0,472 | 10,936 | 55,764 | 323,206 | 0,96 | 13,843 | 264,261 | 4,27 | 40,32 | 1,18 | 1,41 |
| 2012 | 0,463 | 11,153 | 56,228 | 334,647 | 0,96 | 13,841 | 278,102 | 4,15 | 40,65 | 1,11 | 1,36 |
| 2013 | 0,481 | 12,047 | 56,709 | 346,089 | 0,96 | 13,845 | 291,947 | 4,26 | 41 | 1,06 | 1,30 |
| 2014 | 0,465 | 12,148 | 57,174 | 357,530 | 0,96 | 13,841 | 305,789 | 4,09 | 41,33 | 1,00 | 1,25 |
| 2015 | 0,494 | 13,498 | 57,668 | 368,972 | 0,96 | 13,848 | 319,637 | 4,3 | 41,69 | 0,94 | 1,20 |
| 2016 | 0,508 | 14,572 | 58,176 | 380,413 | 0,97 | 13,851 | 333,489 | 4,38 | 42,06 | 0,90 | 1,15 |
| 2017 | 0,514 | 15,497 | 58,690 | 391,855 | 0,97 | 13,853 | 347,342 | 4,39 | 42,43 | 0,84 | 1,09 |
| 2018 | 0,506 | 16,087 | 59,196 | 403,297 | 0,97 | 13,851 | 361,193 | 4,29 | 42,8 | 0,79 | 1,04 |
| 2019 | 0,509 | 17,056 | 59,705 | 414,738 | 0,97 | 13,851 | 375,045 | 4,27 | 43,16 | 0,73 | 0,97 |
| 2020 | 0,505 | 17,927 | 60,210 | 426,180 | 0,97 | 13,851 | 388,897 | 4,2 | 43,53 | 0,68 | 0,91 |
| 2021 | 0,513 | 19,329 | 60,723 | 437,621 | 0,97 | 13,853 | 402,750 | 4,23 | 43,9 | 0,63 | 0,85 |
| 2022 | 0,513 | 20,578 | 61,236 | 449,063 | 0,98 | 13,853 | 416,603 | 4,2 | 44,27 | 0,58 | 0,79 |
| 2023 | 0,497 | 21,243 | 61,733 | 460,504 | 0,98 | 13,849 | 430,452 | 4,03 | 44,63 | 0,54 | 0,74 |
| 2024 | 0,507 | 23,222 | 62,240 | 471,946 | 0,98 | 13,851 | 444,303 | 4,07 | 45 | 0,50 | 0,69 |
The dynamics of the annual production of oil, liquid, annual water injection is shown in fig. 5.1.
Rice. 5.1. Dynamics of annual production of oil, liquid, annual water injection
The dynamics of cumulative oil and liquid production and cumulative water injection is shown in fig. 5.2.
Rice. 5.2. Dynamics of cumulative oil and liquid production and cumulative water injection
The dynamics of CIN, the rate of selection from NCDs and the rate of selection from TIZs are shown in Fig. 5.3.
Rice. 5.3. Dynamics of CIN, the rate of selection from NCDs and the rate of selection from TIZ
The above analyzes of the effectiveness of microbiological effects showed a very low efficiency of this method.
As an application of technology for increasing the oil-cleaning capacity of a displacing agent in wells developed in low-permeability reservoirs during primary flooding, the injection of water-soluble surfactants (surfactants AF 9 -12) is considered.
The development of water-flooded formations is more effectively carried out with the use of oil-soluble surfactants (AF 9 -6).
During the injection of aqueous dispersions of oil-soluble nonionic surfactants in the reservoir, a microemulsion slug with a low oil content, good oil-displacing ability and viscosity close to oil viscosity is formed at the displacement front, which increases the displacement efficiency and reservoir coverage by waterflooding.
As the most typical example of the application of technologies for restricting the mobility of an injected agent in zones of high water saturation, a technology using composite systems based on encapsulated polymer systems (CPS) and injection of a dispersed colloidal material (DCM) is considered.
LIST OF USED LITERATURE
1. Zheltov Yu.P. Development of oil fields. - M.: Nedra, 1998.
2. Ibatullin R.R. Theoretical Foundations of Oilfield Development Processes: A Course of Lectures. Part 1. Systems and modes of development: Educational and methodical manual. - Almetyevsk: AGNI, 2007.
3. Ibatullin R.R. Theoretical Foundations of Oilfield Development Processes: A Course of Lectures. Part 2. Processes of influencing formations (Technologies and methods of calculation): Educational and methodological manual. - Almetievsk: AGNI, 2008.
4. Ibatullin R.R., Garipova L.I. Collection of problems on the theoretical foundations of the development of oil fields. - Almetievsk: AGNI, 2008.
5. Muslimov R.Kh. Modern Methods for Increasing Oil Recovery: Design, Optimization and Evaluation of Efficiency: Textbook. - Kazan: "Feng" publishing house of the Academy of Sciences of the Republic of Tatarstan, 2005.
6. Increased oil recovery at a late stage of field development (methods, theory, practice) /R.R. Ibatullin, N.G. Ibragimov, Sh.F. Takhautdinov, R.S. Khisamov. - M .: Nedra - Business Center, 2004.
7. Rastorgueva L.G., Zakharova E.F. A methodological guide for the development of a graduation project in accordance with the requirements of the standards for the design of the text and graphic part. Almetyevsk 2007.
8. Lipaev A.A., Musin M.M., Yangurazova Z.A., Tukhvatullina G.Z. Methodology for calculating technological indicators of the development of oil fields: Textbook. - Almetyevsk, 2009 - 108 p.
Information about the work "Increased oil recovery using microbiological impact on the example of the Zapadno-Leninogorskaya area of the Romashkinskoye field of the NGDU "Leninogorskneft""
The effectiveness of oil field development systems with flooding is largely determined by the completeness of the involvement in the development of commercial oil reserves and the nature of their production. Both the rate of production and the completeness of oil extraction from the bowels depend on this.
Under flooding conditions, the completeness of the development of productive formations primarily depends on the degree of coverage of the development object both in terms of area and section, which is largely determined by the nature of the movement of injected water and formation water. Therefore, the main attention in the geological and field analysis should be given to the issues of formation coverage by the effect of injected water and the features of water movement through productive formations.
Among the geological and physical factors affecting the waterflooding process are the filtration properties of productive formations, the nature and degree of their heterogeneity, the viscosity properties of the saturating the formations and the fluids injected into them, etc.
The main technological factors influencing waterflooding and oil recovery are: production well grid parameters, waterflooding system layout, development rate, fluid extraction and water injection technology, conditions for development of adjacent reservoirs, the nature of the opening of productive reservoirs in wells.
The processing of observational data on waterflooding of the reservoir makes it possible to establish the current position of the oil-water contact, the external and internal oil-bearing contours at different development dates, including the development analysis date. Knowing the position of the WOC, it is possible to establish the current position of the oil-bearing contour and the volume of the washed part of the reservoir.
At present, in connection with the development of methods for monitoring the development of oil fields, ideas about the nature of movement have significantly expanded. There are two main forms of movement: vertical rise and layer-by-layer watering of the oil reservoir.
As a result of the joint action of a large number of factors in the process of moving through the reservoir, it moves unevenly and usually takes on a very complex geometric shape. In a multi-layer field, due to the difference in the lithological structure of the object in thickness, several independent displacement fronts are formed with different velocities.
(6.2)
Where:
It should be noted that in this case, watering of the oil reservoir from the bottom is also a prerequisite. Thus, for multilayer fields with clearly isolated reservoirs operated by one filter, indirect methods are not applicable. If there is at least a small amount of geophysical surveys for movement control in the course of development, it is necessary to compare geophysical data and calculated data from the proposed indirect control methods. The considered indirect methods give, as a rule, an overestimated reservoir thickness, therefore, if possible, it is desirable to make corrections to the calculated data, which are found from a comparison of geophysical and calculated data.
Indirect methods for determining the current position are used to construct an ideal lift curve (a) or a surface map (b). Both methods serve as the basis for constructing a map of the remaining oil-saturated thickness at the date of the development analysis.
In order to process all movement data during the development process and to reduce all data to one point in time, in many cases it is advisable to build an ideal displacement curve or, in other words, an ideal lift curve.
The methodology for constructing injection effect maps for layers of a multi-layer field is the same as for a single-layer one. It should be borne in mind that if there is no injection effect in any section of a single-layer reservoir, then during artificial lift its reserves are still developed in the depletion mode, and reserves of such a section are usually not developed in a multi-layer reservoir.
In practice, when constructing injection impact maps within the three previously identified groups, three degrees of impact were identified. In the first group (direct connection of injection and withdrawal zones), zones of flowing production, artificial lift and no impact were distinguished. In the second group (there is no direct connection between the zones of injection and withdrawal), the zones of influence are identified through the confluence of adjacent layers and the zone of lack of connection with injection. In the third group - the opening zone only by injection wells and the zone of no influence on low-productive reservoirs. All of these zones are included in .
Identification of different zones subject to unequal influence of injection allows to differentiate the reservoir reserves and determine the reserves that are actively involved in the development, and are not covered by the development under the existing system and are subject to drilling, that is, to determine the structure of oil reserves at the date of the development analysis.
Improvement of development systems should go along the path of increasing the coverage by the impact of productive formations, eliminating zones and sections of formations that are not affected or weakly affected by injection.
6.3. Analysis of the dynamics of the current sweep, displacement and oil recovery factors in the flooded formation zone
One of the most important tasks that arise when analyzing the development of oil fields at a late stage is to identify the nature of the distribution of the remaining balance oil reserves within the initial oil-containing volume of the deposit.
This is necessary, first of all, for the correct assessment of the remaining recoverable oil reserves with conventional development methods and known methods for intensifying oil production.
Knowledge of the nature of the distribution of residual balance oil reserves is especially important for the effective use of the so-called tertiary methods of enhanced oil recovery (physico-chemical, gas, thermal, mechanical methods -,).
Determination of residual oil reserves, located on the date of analysis in the oil-saturated volume, can be made using the following formulas.
The sum of the deposit volumes and is equal to the initial oil-containing volume of the deposit:
The balance of oil reserves (approximately) can be written
(6.7)
Where:
The volume can be represented as consisting of two parts:
(6.8)
Where:
Therefore, and can be represented as the sum
The volume of the discontinuous part of the formation depends both on the geological structure (presence of lenses and half-lenses, dead-end zones, layering, faults, pinchouts, etc.), and on the formation stimulation system and the distance between production and injection wells. This volume for drilled deposits is determined by zonal maps of oil-saturated thicknesses or by calculating unproduced volumes by profiles. If there are no other data, then it is usually assumed that the volume of the discontinuous part of the reservoir, as well as the balance reserves in this volume, does not change during the development process, because there is no impact on this volume and no oil is extracted from it, i.e. , where: - the initial volume of the discontinuous part of the formation.
For undrilled deposits at the initial stage of design, it is determined by analogy with similar deposits or in accordance with the recommendations contained in the development design manuals.
The main method for determining residual oil reserves is the volumetric method. However, at a late stage of development, the conditions for its application become much more complicated compared to the initial conditions due to the complex configuration of the current boundary between and , that is, the difficulty lies in determining the current position of the waterflooding front (current ) and the current oil-bearing contours.
As is known, when oil is displaced by water, the oil recovery coefficient is considered as the product of three coefficients
(6.10)
Where:
The displacement efficiency is understood as the ratio of the volume of oil displaced after a long, repeated flushing of a rock sample to the initial oil-saturated volume. This coefficient is set according to the results of laboratory studies on rock samples and, by its physical nature, characterizes the maximum oil recovery during long-term flushing from a continuous part of the formation.
(6.11)
Where:
The waterflood sweep ratio (often referred to as the waterflood ratio) is the ratio of the volume of the washed part of the reservoir to the volume of the reservoir occupied by mobile oil, i.e. continuous reservoir volume - . This coefficient depends mainly on the permeability heterogeneity of the formation, the ratio of oil and water viscosities, the degree of water cut in production wells when they are turned off. See below for methods for determining sweep efficiency.
Sweep sweep factor - (oil loss factor due to formation discontinuity) is defined as the ratio of the volume (reserves) covered by the impact to the entire (initial) volume (reserves) of the reservoir (deposit).
Since one of the parts of the project document for the development of an oil and gas-oil field is the substantiation of the ultimate oil recovery of the reservoirs, the task of the development analysis is to verify the correctness of the selected coefficients included in the oil recovery formula, namely, the oil-water displacement, oil-gas, gas-oil, gas-water, coefficients displacement and flood coverage. Refinement of the physico-hydrodynamic characteristics of displacement, determined in laboratory conditions, is given in. The method for determining the current sweep and recovery factors is described below.
First way. In the late stage of the development of oil deposits, it is important to identify areas already washed with water and areas still occupied by oil, as well as assessing the reduction in effective oil pay thicknesses in oil saturated areas as a result of movement during development. For this, a map of residual effective oil-saturated thicknesses is used, built on the date of the development analysis, which is used to determine the residual oil reserves.
Oil recovery in the watered part of the reservoir is determined by the following formula
(6.13)
Where:
The watered part of the formation is understood as the volume (oil reserves) enclosed between the initial and current position .
If maps of residual oil-saturated thicknesses are built for different dates of development of an oil deposit with an interval of, for example, two to three years, then it is possible to determine a series of values of the achieved oil recovery in the watered part of the reservoir and obtain the dynamics of this indicator in the process of developing an oil deposit. The curves obtained by the described method well characterize the efficiency of producing reservoirs.
Second way determination of oil recovery in the watered part of the reservoir is associated with the process of in-loop waterflooding.
During in-loop waterflooding during dry oil production, all injected water is used to displace oil, that is, each cubic meter of injected water displaces exactly the same amount of oil from the reservoir. After water breakthrough into production wells along the most permeable interlayers, part of the injected water passes through the washed interlayers.
If we subtract from the total amount of injected water the volume of water produced along with oil from production wells located in the watering zone, that is, near the wells, we get the amount of water that has done useful work, displacing an equal amount of oil
According to the data on the time of appearance of fresh water in the production wells closest to the injection wells, it is possible to approximately determine the boundary of the watering front.
As already noted, in the case of in-loop waterflooding, a very compact displacement front is usually observed, which, at a first approximation, can be considered vertical. If there is a significant "smearing" of the displacement front, then it is desirable to determine the residual effective oil-saturated thicknesses from production wells operating with water, similarly to the previous method.
After that, a map of the effective thicknesses of the flooded formation zone is built. In the zone of complete well watering, the effective thicknesses of the watered zone are equal to the initial effective oil-saturated thicknesses. In the zone bounded by the watering front and the line of full watering of wells, lines of equal current effective thicknesses are built.
By measuring the volume of the watered part of the formation, it is possible to determine the balance oil reserves in the watered zone, which the injected water washed and displaced into the production wells.
Knowing the watered reservoir volume and the amount of oil displaced from the reservoir, equal to the volume of effective injection, it is possible to determine the achieved oil recovery in the watered part of the reservoir
(6.15)
Where:
When using this method, it is advisable to build maps of the effective thicknesses of the watered part of the reservoir during the development process.
Third way in fact, it is a variant of the first method for determining the efficiency of producing a productive formation. Here, as in the second method, a map of the effective thicknesses of the watered part of the reservoir is built, but to calculate the achieved oil recovery and the watered part of the reservoir, the amount of oil extracted from the reservoir is used
(6.16)
Where:
Here it is desirable to obtain the dynamics of the values of the oil recovery factor in the watered part of the reservoir. If the residual effective oil-saturated thicknesses of the reservoir cannot be determined for one reason or another, then it is advisable to determine the oil recovery in the watered zone of the reservoir, that is, the balance reserves in the zone between the initial position and the conditional boundary between watered and waterless wells. Otherwise, the method for determining the achieved oil recovery remains unchanged.
There is also fourth way determination of oil recovery in the watered part of the reservoir, based on the average mark of the current position . Based on all available data, the arithmetic mean of the absolute mark of the current as of the date of analysis is determined. On a pre-constructed graph of the distribution of initial balance reserves by the height of the deposit (), a mark is applied to the average value of the current one and the corresponding flooded oil reserves are found. The method can be used for deposits flooded with bottom water.
6.4. Analysis of the efficiency of the development of an oil deposit by comparing the displacement characteristics
The displacement characteristic, built as a whole for the reservoir, serves as a good illustration of the effectiveness of the development of an oil reservoir, it not only shows the amount of oil recovery achieved at any time, but also shows at what expense of the working agent (water) for displacement this or that oil recovery of the reservoir was obtained .
Currently, in the Ural-Volga region and in Western Siberia, there are a large number of oil deposits that are in a late or even final stage of development, from which appropriate displacement characteristics can be built. From these oil reservoirs, analogue reservoirs should be selected, and the displacement characteristics of the analog reservoir and the analyzed reservoir should be compared in order to determine which of the compared reservoirs is developed more efficiently, and try to find out the reasons for this.
When selecting an analogous oil reservoir, one should be guided by the proximity of the following parameters of oil reservoirs, which largely determine the course of the displacement characteristic:
ratio of oil and water viscosities in reservoir conditions;
reservoir permeability;
net-to-gross ratio;
initial oil saturation of the formation;
share of oil reserves located in the oil-water zone.
If we plot the displacement characteristic of the analyzed deposit in semi-logarithmic coordinates on a sufficiently large scale, then most of the displacement characteristic becomes linear, and in most cases, breaks are fixed on it towards a decrease or, conversely, an increase in water consumption for the displacement process. It is necessary to find out the reasons that lead to the observed breaks, establishing what changes in the development system of the deposit, or what geological and technical activities were carried out at the field. The nature (direction) of the breaks will indicate whether these activities have led to an increase in the efficiency of the development of an oil deposit or, conversely, to a decrease in its efficiency.
1A comparison is made of the calculation of the effectiveness of the use of hydrochloric acid treatment according to the displacement characteristics and according to the actual data on the wells of the Tashly-Kul field. The following displacement characteristics are considered: Sazonov, Maksimov, Davydov, Pirverdyan, Kambarov, Nazarov. According to the equations of dependencies, graphs are built and regression equations are derived. By substituting the values of the current fluid production into the resulting equations, we obtain the possible oil production without the use of processing. By subtracting the calculated data from the actual data, we obtain additional oil production as a result of the application of hydrochloric acid treatment. Comparing the results of calculating the effectiveness of the application of the impact, carried out according to the actual data and the displacement characteristics, we find significant differences. We conclude that the results calculated from the displacement characteristics are more objective, since they take into account the actual water cut and operating conditions corresponding to a given amount of liquid flow rate.
hydrochloric acid treatment (HCO)
displacement characteristics
current flow rate
extra loot
bottomhole formation zone (BFZ)
well
1. Bocharov V.A. Development of oil reservoirs under conditions of manifestation of the initial pressure gradient. – M.: VNIIOENG, 2000. – 252 p.
2. Kulbak S. Theory of informativity and statistics. – M.: Nauka, 1967. – 408 p.
3. Mirzajanzade A.Kh., Stepanova G.S. Mathematical theory of experiment in oil and gas production. – M.: Nedra, 1977. – 229 p.
4. Mirzajanzade A.Kh., Khasanov M.Zh., Bakhtizin R.N. Etudes on modeling complex systems in oil and gas production. - Ufa: Gilem, 1999. - 464 p.
5. Umetbaev V.G., Merzlyakov V.F., Volochkov N.S. Capital repairs of wells. Insulation work. - Ufa: RIC ANK "Bashneft", 2000. - 424 p.
6. Fattakhov I.G. Integration of Differential Problems of Oil Production Intensification with Applied Programming // Izvestia of Higher Educational Institutions. Oil and gas. - 2012. - No. 5. - P. 115–119.
7. Fattakhov I.G., Kuleshova L.S., Musin A.A. Method for processing the results of experimental studies on the example of polymeric acid impact on the bottomhole zone of production wells using special software // Automation, telemechanization and communication in the oil industry. - 2009. - No. 3. - P. 26–28.
8. Shvetsov I.A., Manyrin V.N. Physico-chemical methods for increasing oil recovery // Analysis and design. - Samara, 2000. - 336 p.
9. Fattakhov I.G. and others. Certificate of state registration of the computer program No. 2012611957. "Research". 2012.
The problem of creating a reliable and sufficiently reliable methodology for forecasting development indicators is relevant and most important, despite the long and painstaking work of many oil scientists and almost all branch and specialized institutes of the oil industry.
At the moment, there are two fundamentally different approaches that can be used to predict the technological indicators of oil field development.
The first is based on the characteristic of oil displacement by water. In this case, indicators of the history of the development of oil deposits are used.
The second approach is carried out with the help of hydrodynamic mathematical models of the process of oil displacement by water from a heterogeneous reservoir.
Displacement characteristics also make it possible to observe the results of geological and technical measures carried out in order to increase oil recovery.
Let's calculate the efficiency of using hydrochloric acid treatment (HAT) in the conditions of carbonate reservoirs of the Tashly-Kul field according to actual data and displacement characteristics.
In table. Figure 1 shows the performance of wells No. 1573, 1817, 1747, 1347, 1306, 1310, 1348, 1353 before the acid treatment.
According to the report of NGDU "Tuimazaneft" for December 2012 on the implementation of geological and technical measures, it can be seen that after the acid treatment at the wells under consideration there was a significant increase in oil production (Table 2).
Let us calculate the actual increase in oil production by wells (Table 3):
∆Qн = Qн (after) - Qн (before).
Table 1
Development indicators before impact
|
Well number |
|||
table 2
Development indicators after the impact
Let's calculate the technological efficiency of using hydrochloric acid treatment (HAT) in wells according to the displacement characteristics. In this paper, we consider the possibility of using the following displacement characteristics:
1. Sazonova Qn = A + B∙lnQzh.
2. Maksimov Qn = A + B∙lnQv.
3. Davydov Qн = А + В∙(Qv/Ql).
4. Pirverdyan
5. Kambarova Qn \u003d A + B / Qzh.
6. Nazarova Qzh/Qn = A + B∙Qv,
where Qn is the current oil production in the well; Qv - current water production in the well; Qzh - current fluid production in the well; A, B - coefficients of the model, which are determined using the least squares method.
To do this, we plot the dependences Ql (lnQl) (Fig. 1), Ql (lnQv) (Fig. 2), Ql (Qv/Ql) (Fig. 3), Ql (Fig. 4), Ql (Fig. 5) , Ql/Qn (Qv) (Fig. 6).
By substituting the actual values of the current fluid production after the acid treatment, three values of the possible current oil production are determined, which could be obtained if the stimulation had not been carried out. By subtracting these calculated values of current production from the actual production on the same date, three values of possible additional oil production as a result of the acid treatment are determined (Table 4).
Rice. 1. Characterization of displacement according to the Sazonov method
Rice. 2. Characteristics of displacement according to the Maksimov method
Rice. 3. Characterization of displacement according to the Davydov method
Rice. 4. Characterization of displacement according to the Pirverdyan method
Rice. 5. Characteristics of displacement according to the Kambarov method
Rice. 6. Characteristics of displacement according to the Nazarov method
Table 4
The results of applying the standard deviation according to the displacement characteristics
|
Well number |
Qn fact, t/day |
According to Sazonov |
According to Maksimov |
According to Davydov |
According to Pirverdyan |
According to Kambarov |
According to Nazarov |
||||||
|
Qn calc, t/day |
∆Qн, t/day |
Qn calc, t/day |
∆Qн, t/day |
Qn calc, t/day |
∆Qн, t/day |
Qn calc, t/day |
∆Qн, t/day |
Qn calc, t/day |
∆Qн, t/day |
Qn calc, t/day |
∆Qн, t/day |
||
We see that the result of calculating the effectiveness of the application of the impact, carried out on the basis of actual data, differs from the result calculated on the basis of displacement characteristics. The latter is more objective, since it takes into account the actual water cut and operating conditions corresponding to a given amount of liquid flow rate.
Thus, the characteristics of oil displacement by water are one of the tools for calculating the efficiency of reserves development. In addition, the characteristics are applicable and reliable for the analysis and forecast of the oil production process both at a certain stage of development and in the future, as they are based on actual reservoir development indicators and take into account the geological and physical characteristics of the reservoir and fluids saturating it, as well as features well operation, system and density of their placement.
Reviewers:Khuzina L.B., Doctor of Technical Sciences, Associate Professor, Professor, Head. Department "Drilling of oil and gas wells", GBOU VPO "Almetyevsk State Oil Institute", Almetyevsk;
Yagubov E.Z., Doctor of Technical Sciences, Professor, Vice-Rector for Academic Affairs, Ukhta State Technical University, Ukhta.
The work was received by the editors on December 19, 2014.
Bibliographic link
Fattakhov I.G., Novoselova D.V. CALCULATION OF THE EFFICIENCY OF THE APPLICATION OF HYDROCORIC ACID TREATMENT BY CHARACTERISTICS OF DISPLACEMENT // Fundamental Research. - 2014. - No. 12-6. - S. 1186-1190;URL: http://fundamental-research.ru/ru/article/view?id=36298 (date of access: 01/05/2020). We bring to your attention the journals published by the publishing house "Academy of Natural History"
ANNOTATION
The article deals with the issues of forecasting development indicators based on the characteristics of oil displacement by water using material balance methods. The material balance method allows solving a number of development problems, including the forecasting of technological indicators. The following data are required to predict the development of an oil deposit using the material balance method: initial and average reservoir pressures, volumes of accumulated and injected fluid, volumes of water intruding into the reservoir, volumetric coefficients of oil, gas and water, phase permeabilities, dynamic viscosities of oil and gas. The accuracy of the indicators calculated using the material balance method depends on the selection of the initial data, their usefulness, and on certain assumptions that form the basis of the calculation equations. It is also possible to predict the current oil saturation depending on the current oil recovery and the characteristics of oil, gas and water, and for the water drive mode, the current average oil saturation for the reservoir is predicted by determining the volume of water invading the reservoir.
Based on the equations of flow of oil and gas in the reservoir, determine the relative permeability.
ABSTRACT
In article questions of the forecast of indicators of development for characteristics of replacement of oil by water with use of methods of material balance are considered. The method of material balance allows to solve a number of problems of development including forecasting of technological indicators. The following data are necessary for forecasting of indicators of development of the oil pool by a method of material balance: initial and average reservoir pressures, volumes of the saved-up and pumped liquid, the water volumes interfering in layer, volume coefficients of oil, gas and water phase permeability, dynamic viscosity of oil and gas. Accuracy of the indicators counted by means of a method of material balance depends on selection of basic data, their full value and from the accepted some assumptions which are the basis for the settlement equations.
It is also possible to predict the current oil saturation depending on the current characteristics of oil and oil, gas and water, and for water drive reservoir on the current average oil saturation is predicted by determining the amount of invading water reservoir.
Based on the equations of flow of oil and gas reservoir, the relative permeability is determined.
We can assume that this method gives more reliable results, keeping unchanged the existing system and the development of naturally reducing the current selection of the liquid at a late stage.
The material balance method allows solving a number of development problems, including the forecasting of technological indicators.
The following data are required to predict the performance of an oil deposit using the material balance method:
- initial and average reservoir pressures;
- volumes of accumulated and pumped liquid;
- volumes of water invading the formation;
- volumetric coefficients of oil, gas and water;
- phase permeability;
- dynamic viscosities of oil and gas.
This method makes it possible to predict the current oil recovery based on field data.
/Sapashov.files/image002.png){kind=small}
, (1)
where: - accumulated volume of oil extracted from the reservoir;
is the initial volume of oil in the reservoir;
are, respectively, the volumetric coefficients of oil at pressure and p0;
is the volumetric coefficient of the gas at p;
- respectively, the volumes of dissolved gas per unit volume of oil at the initial, current reservoir pressure and on the surface.
It is also possible to predict the current oil saturation depending on the current oil recovery and the characteristics of oil, gas and water, and for the water drive mode, the current average oil saturation for the reservoir is predicted by determining the volume of water invading the reservoir.
Based on the equations of oil and gas flow in the reservoir, determine the relative permeability
/Sapashov.files/image009.png){kind=small}
, (2)
where: - respectively, phase permeability for oil and gas;
– total gas-oil factor;
are, respectively, the dynamic viscosities of oil and gas.
The accuracy of the indicators calculated using the material balance method depends on the selection of the initial data, their usefulness, and on certain assumptions that form the basis of the calculation equations.
If in calculations by the material balance method the characteristics of reservoir oils obtained in the process of degassing in a bomb are used, which differ sharply from the phenomena occurring in the reservoir, then the prediction of the average reservoir pressure leads to significant distortions of the results.
In a number of cases, the forecasting of oil field development indicators during flooding in fractured and fractured porous reservoirs is carried out only on the basis of solving the material balance equation.
The relationship between the total oil production and the total liquid production is understood as the displacement characteristic, but later the displacement characteristics began to be understood as the dependence of the total oil production on the total water production, as well as the dependence of various ratios between the total quantities of oil, water and liquid.
In addition, the dependence between the content of oil or water in the flow and the total withdrawals of oil, water and liquid began to be attributed to the displacement characteristics.
When predicting the development indicators of a long-term exploited field, when significant actual data on the extraction of oil and water are known, the calculation can be carried out using the displacement characteristics.
To do this, first interpolate the actual curves such as water cut - cumulative oil production, water cut - cumulative volume of injected water, current oil recovery - cumulative volume of injected water, and then extrapolate the obtained dependencies in order to obtain predictive indicators.
Most of the equations used to process displacement curves were obtained empirically as a result of field data analysis (methods of Kambarov, Nazarov, Kopytov, etc.). Some of the models were obtained as a result of a theoretical study of the process of oil displacement by water in some simplified formulations.
The analysis shows that displacement characteristics can be basically divided into two groups:
- integral displacement characteristics;
- differential displacement characteristics.
The first group includes all dependences, in the formulas of which the total oil, water and liquid extractions appear.
The second one includes all dependences, the formulas of which include the content of oil or water and the total withdrawals of oil, water and liquid.
As an alternative to traditional methods of displacement characteristics, one can consider the development equations used in the analytical method for calculating the technological indicators of reservoir development in a water-driven mode, used in TatNIPI oil.
In this method, it is assumed that the dynamics of the current oil production and the estimated fluid production under constant development conditions obey the exponential law. In this case, fluid production will decrease as watered wells are shut down, which is typical for the late development stage. In addition, this technique takes into account the time-varying development conditions.
The TatNIPI oil method is based on the following two development dependencies:
/Sapashov.files/image014.png)
(3)
where: - respectively, the current flow rates of oil and water;
– initial amplitude flow rate of all drilled and put into operation wells;
- respectively, the accumulated withdrawals of oil and liquid;
- respectively, the potential recoverable reserves of oil and liquid with an unlimited development period; - conversion factor.
In order to be able to use equations (3), it is necessary to approximate the observed actual dependences of the specific values of the current oil and water withdrawals by piecewise linear functions, reflecting the impact of the technological measures taken on the predicted final development indicators in dynamics.
Further, having determined the main parameters of the developed object /Sapashov.files/image020.png){kind=small}
on the straight sections of the curves of the transformed actual dependencies, the filtration parameter is calculated.
Thus, with the help of the proposed development equations, adapted to the history of the operation of the object, it is possible to predict the current and final development indicators.
It should be noted that the noted method needs further improvement, since the applied development equations do not cover the entire period of operation of the object.
Bibliography:
1. Evaluation of the effectiveness of production facilities at a late stage by methods of displacement characteristics. / R.G. Khamzin, R.T. Fazlyev. - TatNIPI oil, Interval, No. 9 (44), 2002.
2. Reference guide to the design of the development and operation of oil fields. Development design, oil production / Sh.K. Gimatutdinov, I.T. Mishchenko, A.I. Petrov and others - M .: Nedra, 1983, 463 pp., vol. I, 455 pp., vol. II.
References:
1. Khamzin R.G., Fazlyev R.T. Evaluating the effectiveness of production facilities at a later stage by techniques of displacement characteristics. TatNIPIneft, Interval Publ., no. 9 (44), 2002. (In Russian).
2. Gimatutdinov Sh.K., Mishchenko I.T., Petrov A.I. Reference manual for the design, development and exploitation of oil fields. Design development, oil production. Moscow, Nedra Publ., 1983, 463 p., vol. I, 455 p., vol. II. (In Russian).
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