Extra-high water content stage oil field recovery ratio calibration method, device and equipment and storage medium

Abstract

The invention relates to the technical field of oil reservoir engineering, in particular to an ultra-high water content stage oil field recovery ratio calibration method, device and equipment and a storage medium, and the method comprises the steps that the limit water content of an ultra-high water content stage oil field is determined according to a relation curve of the oil field water-oil ratio and the annual oil production; according to the A type, B type, C type and D type water drive characteristic curves, determining the A type, B type, C type and D type water content and cumulative yield relation curves; determining the accumulated oil production corresponding to the limit water content according to the relation curve of the A type water content, the B type water content, the C type water content and the D type water content and the accumulated yield; and the calibrated recovery ratio is determined according to the accumulated oil production quantity. According to the method, the limit water content of the extra-high water content oil reservoir is calculated, fitting is carried out by combining a water drive characteristic curve with actual data, and therefore the novel method for calibrating the oil field recovery efficiency in the extra-high water content stage is established, and a powerful reserve guarantee basis is provided for planning, deployment and potential tapping adjustment in the later period of oil field development.

Description

Technical Field

[0001] This invention relates to the field of reservoir engineering technology, and is a method, apparatus, equipment and storage medium for calibrating oil recovery rate in oilfields with ultra-high water cut. Background Technology

[0002] Conventional methods for calibrating oilfield recovery rates mainly employ empirical formulas, analogies, and numerical simulations. Empirical formulas utilize reservoir geological parameters such as average effective porosity, permeability, and underground crude oil viscosity to calculate the recovery rate. For example, Lu Huijing, in her article "Research and Application of Oilfield Recovery Rate Calibration Methods," used empirical formulas to calculate the recovery rate of the Zhongyuan oilfield. However, this method only reflects the initial recovery rate under original conditions, not the final recovery rate, and it cannot calculate the recovery rate of reservoirs with a water cut exceeding 98%. Analogies utilize dynamic oilfield data combined with charts for recovery rate calibration. For instance, Duan Yu, in his article "Research on Recovery Rate Calibration Methods in the Bohai Oilfield and Its Application in the Bohai A Oilfield," used four types of water drive curves (A, B, C, and D) to create a chart depicting the water cut increase pattern. Based on actual production conditions, the type of curve with the highest degree of fit was selected to further calculate the oilfield recovery rate. However, the analogy method can only calculate the recovery rate of oilfields with a water cut of less than 98%. When using this method to calculate the recovery rate of oilfields with extremely high water cuts, the result is lower than the actual recovery rate of the oilfield. The numerical simulation method calibrates the recovery rate based on a static model and combined with dynamic production data. For example, Ding Jian used the numerical simulation method to calibrate the Bohai Bay reservoir in his paper "Research on the Recalibration Method of Recovery Rate in the Mid-term of Oilfield Development—Taking a Certain Oilfield in Bohai Bay as an Example." This method has high requirements for data accuracy and operation, and the calibration is quite difficult.

[0003] Currently, my country's national standards for the oil and gas industry are based on a water cut of 98%, using water drive characteristic curves to calibrate the recovery rate of developed sandstone reservoirs. Existing technology cannot calibrate the recovery rate of oilfields with ultra-high water cut (water cut > 98%). Therefore, a method for calibrating the recovery rate of oilfields with ultra-high water cut is proposed to address this issue. Summary of the Invention

[0004] This invention provides a method for calibrating the recovery rate of oilfields in the ultra-high water-cut stage, which overcomes the shortcomings of the prior art and can effectively solve the problem that the prior art cannot calibrate the recovery rate of ultra-high water-cut reservoirs.

[0005] One of the technical solutions of this invention is achieved through the following measures: a method for calibrating the recovery rate of oilfields in the ultra-high water-cut stage, comprising the following steps:

[0006] The limiting water cut of oilfields in the ultra-high water cut stage is determined based on the relationship curve between the water-oil ratio and annual oil production.

[0007] Based on the water drive characteristic curves of types A, B, C, and D, determine the relationship curves between water cut and cumulative yield for types A, B, C, and D;

[0008] The cumulative oil recovery corresponding to the limiting water cut is determined based on the relationship curves between water cut and cumulative production for types A, B, C, and D.

[0009] The calibrated recovery rate is determined based on the cumulative oil production.

[0010] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:

[0011] The limiting water cut of oilfields in the ultra-high water cut stage, determined based on the relationship curve between the oilfield water-oil ratio and annual oil production, includes:

[0012] The expression for the limiting water cut is determined based on the relationship between crude oil production and the water-oil ratio in an oilfield. The relationship between crude oil production and the water-oil ratio in an oilfield, and the expression for the limiting water cut, are as follows:

[0013] LogWOR = a + bQ O Formula 1-1

[0014]

[0015] Where WOR is the water-oil ratio of the oilfield, and Q is... O For crude oil production, f wL denoted as limiting moisture content, a is the curve intercept, and b is the slope;

[0016] Based on the relationship curve between the oilfield water-oil ratio and annual oil production, the limiting water cut is obtained by regression analysis to obtain the curve intercept 'a'.

[0017] The above-mentioned determination of the relationship curves between water cut and cumulative yield for types A, B, C, and D water drive based on their characteristic curves includes:

[0018] Based on actual oilfield data, characteristic curves for Type A, Type B, Type C, and Type D waterdrive were plotted. Straight-line segments of the waterdrive characteristic curves were selected, and regression analysis was performed to obtain the slope A of these straight-line segments. i and intercept B i (i = 1, 2, 3, 4);

[0019] Based on slope A i and intercept B i Determine the relationship curves between moisture content and cumulative yield for types A, B, C, and D.

[0020] The expressions for the moisture content and cumulative yield relationship curves of types A, B, C, and D are as follows:

[0021] Curve showing the relationship between moisture content and cumulative yield of Form A:

[0022] Curve showing the relationship between moisture content and cumulative yield of type B:

[0023] Curve showing the relationship between moisture content and cumulative yield of type C:

[0024] Curve showing the relationship between moisture content and cumulative yield of type D:

[0025] Among them, f w Moisture content; N P To accumulate oil production, 10 4 t; A i (i = 1, 2, 3, 4) are the intercepts of the characteristic curves of type A, type B, type C, and type D water drive, respectively; B i (i = 1, 2, 3, 4): These are the slopes of the characteristic curves for type A, type B, type C, and type D water drive, respectively.

[0026] The above determination of the cumulative oil recovery corresponding to the limiting water cut based on the relationship curves between water cut and cumulative production for types A, B, C, and D includes:

[0027] The recovery rate is calculated by selecting the curve with the highest fitting accuracy and the smallest error from the water cut and cumulative production relationship curves of types A, B, C and D. The cumulative oil production corresponding to the limiting water cut is then calculated based on the limiting water cut.

[0028] The above-mentioned determination of the calibrated recovery rate based on the cumulative oil production includes: dividing the cumulative oil production (which is the recoverable reserves) by the geological reserves to obtain the calibrated recovery rate.

[0029] The second technical solution of the present invention is achieved through the following measures: a device for calibrating the oil recovery rate in oilfields with ultra-high water cut stages, comprising:

[0030] The limiting water cut determination module is used to determine the limiting water cut of oilfields in the ultra-high water cut stage based on the relationship curve between the water-oil ratio and annual oil production.

[0031] The moisture content and cumulative yield curve module is used to determine the relationship curves between moisture content and cumulative yield for types A, B, C, and D water drive based on the characteristic curves of types A, B, C, and D water drive.

[0032] The cumulative oil recovery determination module is used to determine the cumulative oil recovery corresponding to the limiting water cut based on the relationship curves between water cut and cumulative production for types A, B, C, and D.

[0033] The calibration recovery rate determination module is used to determine the calibration recovery rate based on the cumulative oil production.

[0034] The third technical solution of the present invention is achieved through the following measures: a storage medium storing a computer program that can be read by a computer, the computer program being configured to execute the oil recovery calibration method for the ultra-high water cut stage oilfield when running.

[0035] The fourth technical solution of the present invention is achieved through the following measures: an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the computer program is loaded and executed by the processor to implement the method for calibrating the oil recovery rate of the ultra-high water cut stage oilfield.

[0036] This invention proposes a new method for calibrating oilfield recovery rates in the ultra-high water-cut stage by calculating the limiting water cut of ultra-high water-cut reservoirs and fitting the water drive characteristic curve with actual data. This provides a strong basis for the planning, deployment, and adjustment of potential tapping in the later stages of oilfield development. Attached Figure Description

[0037] Appendix Figure 1 This is a schematic diagram of the oilfield recovery rate calibration device for the ultra-high water cut stage of the present invention.

[0038] Appendix Figure 2 This is a graph showing the relationship between the water-oil ratio and production in the OBJ1 layer of the Kumkol South oilfield in Example 10 of the present invention.

[0039] Appendix Figure 3 This is a fitting diagram of the water cut of the OBJ1 layer in the Kumkol South oilfield in Example 10 of the present invention. Detailed Implementation

[0040] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0041] The present invention will be further described below with reference to embodiments:

[0042] Example 1: A method for calibrating the oil recovery rate in an oilfield with extremely high water cut, comprising the following steps:

[0043] The limiting water cut of oilfields in the ultra-high water cut stage is determined based on the relationship curve between the water-oil ratio and annual oil production.

[0044] Based on the water drive characteristic curves of types A, B, C, and D, determine the relationship curves between water cut and cumulative yield for types A, B, C, and D;

[0045] The cumulative oil recovery corresponding to the limiting water cut is determined based on the relationship curves between water cut and cumulative production for types A, B, C, and D.

[0046] The calibrated recovery rate is determined based on the cumulative oil production.

[0047] Example 2: As an optimization of the above example, the limiting water cut of oilfields in the ultra-high water cut stage is determined based on the relationship curve between the oilfield water-oil ratio and annual oil production, including:

[0048] The expression for the limiting water cut is determined based on the relationship between crude oil production and the water-oil ratio in an oilfield. The relationship between crude oil production and the water-oil ratio in an oilfield, and the expression for the limiting water cut, are as follows:

[0049] LogWOR = a + bQ O Equation 1-1

[0050]

[0051] Where WOR is the water-oil ratio of the oilfield, and Q is... O For crude oil production, f wL denoted as limiting moisture content, a is the curve intercept, and b is the slope;

[0052] Based on the relationship curve between the oilfield water-oil ratio and annual oil production, the limiting water cut is obtained by regression analysis to obtain the curve intercept 'a'.

[0053] Example 3: As an optimization of the above examples, the relationship curves between water cut and cumulative yield for types A, B, C, and D are determined based on the characteristic curves of type A, B, C, and D water drive, including:

[0054] Based on actual oilfield data, characteristic curves for Type A, Type B, Type C, and Type D waterdrive were plotted. Straight-line segments of the waterdrive characteristic curves were selected, and regression analysis was performed to obtain the slope A of these straight-line segments. i (i = 1, 2, 3, 4) and intercept B i (i = 1, 2, 3, 4);

[0055] Based on slope A i (i = 1, 2, 3, 4) and intercept B i (i = 1, 2, 3, 4) Determine the relationship curves between moisture content and cumulative yield for types A, B, C, and D.

[0056] Example 4: As an optimization of the above examples, the expressions for the relationship curves between moisture content and cumulative yield for types A, B, C, and D are as follows:

[0057] Curve showing the relationship between moisture content and cumulative yield of Form A:

[0058] Curve showing the relationship between moisture content and cumulative yield of type B:

[0059] Curve showing the relationship between moisture content and cumulative yield of type C:

[0060] Curve showing the relationship between moisture content and cumulative yield of type D:

[0061] Among them, f w Moisture content, %; N P To accumulate oil production, 10 4 t; A i (i = 1, 2, 3, 4) are the intercepts of the characteristic curves of type A, type B, type C, and type D water drive, respectively; B i (i = 1, 2, 3, 4) are the slopes of the characteristic curves of type A, type B, type C, and type D water drive, respectively.

[0062] Example 5: As an optimization of the above examples, the cumulative oil recovery corresponding to the limiting water cut is determined based on the relationship curves between water cut and cumulative production for types A, B, C, and D, including:

[0063] The recovery rate is calculated by selecting the curve with the highest fitting accuracy and the smallest error from the water cut and cumulative production relationship curves of types A, B, C and D. The cumulative oil production corresponding to the limiting water cut is then calculated based on the limiting water cut.

[0064] Example 6: As an optimization of the above examples, determining the calibrated recovery rate based on the cumulative oil production includes dividing the cumulative oil production (which is the recoverable reserves) by the geological reserves to obtain the calibrated recovery rate.

[0065] Example 7: This oilfield recovery rate calibration device for ultra-high water cut stage includes:

[0066] The limiting water cut determination module is used to determine the limiting water cut of oilfields in the ultra-high water cut stage based on the relationship curve between the water-oil ratio and annual oil production.

[0067] The moisture content and cumulative yield curve module is used to determine the relationship curves between moisture content and cumulative yield for types A, B, C, and D water drive based on the characteristic curves of types A, B, C, and D water drive.

[0068] The cumulative oil recovery determination module is used to determine the cumulative oil recovery corresponding to the limiting water cut based on the relationship curves between water cut and cumulative production for types A, B, C, and D.

[0069] The calibration recovery rate determination module is used to determine the calibration recovery rate based on the cumulative oil production.

[0070] Example 8: A storage medium storing a computer program that can be read by a computer, the computer program being configured to execute the oil recovery calibration method for the ultra-high water cut stage oilfield when running.

[0071] Example 9: An electronic device, including a processor and a memory, wherein the memory stores a computer program, which is loaded and executed by the processor to implement the oil recovery calibration method for the ultra-high water cut stage oilfield.

[0072] The processor described above can be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an ASIC, an FPGA, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. It can also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc. The memory can include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, read-only memory, portable hard drives, magnetic disks, or optical disks.

[0073] This invention provides a method for calibrating the recovery rate of oilfields in the ultra-high water-cut stage, applicable to various types of ultra-high water-cut reservoirs, providing a strong reserve guarantee basis for the planning, deployment, and adjustment of potential tapping in the later stages of oilfield development. Specifically, the method involves calculating the limiting water cut of the ultra-high water-cut reservoir and fitting it with water drive characteristic curves and actual data to establish the oilfield recovery rate calibration for the ultra-high water-cut stage. Compared with existing methods, this invention proposes a new approach to calibrating the oilfield recovery rate in the ultra-high water-cut stage. Its advantages include strong applicability, suitability for various reservoirs, relatively low operational difficulty, and filling a technical gap in the calibration of oilfield recovery rates in the ultra-high water-cut stage.

[0074] Example 10: This method for calibrating the recovery rate of oilfields in the ultra-high water-cut stage was specifically implemented in the Kumkol South oilfield in Kazakhstan. Using this method, the recovery rate of the OBJ1 reservoir in the Kumkol South oilfield was calibrated to 59.67%, providing a reliable basis for the comprehensive management of old wells and the deployment of new wells in this oilfield. The specific process is as follows:

[0075] Step 1: Data Statistics

[0076] Statistics were compiled on the annual oil production, water cut, cumulative water production, cumulative oil production, and recovery rate of the OBJ1 layer in the KS oilfield.

[0077] Step 2: Determine the limiting moisture content

[0078] Once a water-driven oilfield enters a declining production phase, if no major adjustments are made and the development method remains unchanged, the relationship between its crude oil production and water-oil ratio will conform to the following:

[0079] LogWOR = a + bQ O Equation 1-1

[0080] If the waste production approaches 0, the limiting water-oil ratio and limiting water content are respectively:

[0081]

[0082] WOR L =10 a Formula 1-3

[0083] Based on the relationship curve between water-oil ratio and annual oil production in the OBJ1 reservoir of the Kumkol South oilfield ( Figure 1 After obtaining the curve intercept 'a' through regression, the limiting water-oil ratio and limiting water cut are obtained. For example, based on the production data of the OBJ1 layer in the Kumkol South oilfield, the calculated curve intercept 'a' is 2.0659, the limiting water-oil ratio is 116.39, and the limiting water cut is 99.15%.

[0084] Step 3: Plot the relationship between moisture content and cumulative yield based on the curves for types A, B, C, and D.

[0085] Based on actual oilfield data, water drive characteristic curves for four types of reservoirs (Type A, Type B, Type C, and Type D) were plotted. After selecting the linear segments, the slopes and intercepts of the linear segments were obtained through regression analysis. The relationship between water cut and cumulative production was then plotted.

[0086] Curve showing the relationship between moisture content and cumulative yield of Form A:

[0087] Curve showing the relationship between moisture content and cumulative yield of type B:

[0088] Curve showing the relationship between moisture content and cumulative yield of type C:

[0089] Curve showing the relationship between moisture content and cumulative yield of type D:

[0090] Among them, f w Moisture content, %; N P To accumulate oil production, 10 4 t, A i (i = 1, 2, 3, 4) are the intercepts of the characteristic curves of type A, type B, type C, and type D water drive, respectively; B i (i = 1, 2, 3, 4) represent the slopes of the waterdrive characteristic curves for types A, B, C, and D, respectively. Based on actual data from the OBJ1 layer in the KS oilfield, waterdrive characteristic curves for the four types (Type A, B, C, and D) of the reservoir were plotted. After selecting straight line segments, the slopes and intercepts of the straight line segments were regressed (see Table 1).

[0091] Step 4: Select the curve with the highest fitting accuracy and smallest error to calculate the recovery rate.

[0092] Based on equations 2-1 to 2-4, curves relating water cut to cumulative production were plotted. Actual data was then used for fitting, and the curve with the highest fitting accuracy and smallest error was selected to calculate the cumulative oil recovery corresponding to the limiting water cut. This value is the recoverable reserves, which, when divided by the geological reserves, yields the calibrated recovery rate. The curve with the highest fitting accuracy and smallest error for this reservoir was the water cut variation curve obtained from the type A water drive characteristic curve. The recoverable reserves calculated using this method are closest to the actual values ​​in the oilfield. When the limiting water cut is 99.15%, the recovery rate calibrated according to the type A curve is 59.67%.

[0093] The recovery rate of the OBJ1 layer in the KS oilfield was calibrated using the method of the present invention, and the final recovery rate of the reservoir was determined to be 59.67%, providing a reliable basis for the comprehensive management of old wells and the deployment of new wells in the oilfield.

[0094] In summary, the invented method for calibrating the recovery rate of oilfields in the ultra-high water-cut stage calculates the limiting water cut of ultra-high water-cut reservoirs and uses water drive characteristic curves combined with actual data for fitting, thereby establishing a new method for calibrating the recovery rate of oilfields in the ultra-high water-cut stage. This method is applicable to various types of ultra-high water-cut reservoirs and achieves effective and reasonable calibration of the recovery rate of oilfields in the ultra-high water-cut stage. It provides a basis for future planning, deployment, and adjustment of potential tapping in oilfields and lays the foundation for achieving economical and effective development of the oilfield.

[0095] The above technical features constitute the preferred embodiment of the present invention, which has strong adaptability and optimal implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the requirements of different situations.

[0096] Table 1

[0097] Serial Number Curve type <![CDATA[Linear regression intercept A i > <![CDATA[Linear regression slope B i > Correlation coefficient 1 Type A -1.3364 0.0033 0.9999 2 Type B -4.2435 0.0038 0.9924 3 Type C 0.5813 0.0006 0.9992 4 T-type 1.2122 0.0006 0.9998

Claims

1. A method for characterizing enhanced water cut stage oilfield recovery, the method comprising: The method comprises the following steps: ​ determining the limit water cut of the oilfield in the extra-high water cut stage according to the oilfield water-oil ratio and annual oil production relationship curve; determining the type A, type B, type C and type D water drive characteristic curve according to the type A, type B, type C and type D water cut and cumulative production relationship curve; determining the cumulative oil production corresponding to the limit water cut according to the type A, type B, type C and type D water cut and cumulative production relationship curve; determining the calibrated recovery rate according to the cumulative oil production.

2. The ultra-high water-cut field recovery calibration method of claim 1, wherein The method for determining the limit water cut of the oilfield in the extra-high water cut stage according to the oilfield water-oil ratio and annual oil production relationship curve comprises the following steps: determining the expression of the limit water cut according to the relationship between the crude oil production and the oilfield water-oil ratio, wherein the relationship between the crude oil production and the oilfield water-oil ratio and the expression of the limit water cut are as follows: LogWOR = a + bQ O Equation 1-1 where WOR is the water-oil ratio, Q O is the crude oil production, f wL is the limiting water cut, a is the curve intercept, and b is the slope; determining the limit water cut after obtaining the curve intercept a by regression according to the oilfield water-oil ratio and annual oil production relationship curve.

3. The ultra-high water cut field recovery calibration method of claim 1 or 2, wherein The method for determining the type A, type B, type C and type D water cut and cumulative production relationship curve according to the type A, type B, type C and type D water drive characteristic curve comprises the following steps: According to the actual data of oil field, the water drive characteristic curves of type A, type B, type C and type D are plotted, the straight line segment of the water drive characteristic curve is selected, and the slope A i and the intercept B i of the straight line segment are obtained by regression, i=1, 2, 3, 4. According to the slope A i and the intercept B i Determine the Type A, B, C, and D water content and cumulative yield relationship curves.

4. The ultra-high water-cut field recovery calibration method of claim 3, wherein The expressions of the type A, type B, type C and type D water cut and cumulative production relationship curve are as follows: The relationship between the water content of the A-type and the cumulative yield: Ethylene type and cumulative yield relationship curve: The relationship between the propyl group content and the cumulative production rate is as follows: Determination of the relationship between the water content and the cumulative production for the Type B: where f w is the water cut; N P is the cumulative oil production, 10 4 t; A i are the intercepts of the type A, B, C, D water drive characteristic curves, respectively, i = 1, 2, 3, 4; B i are the slopes of the type A, B, C, D water drive characteristic curves, respectively, i = 1, 2, 3, 4.

5. The ultra-high water-cut field recovery calibration method according to any one of claims 1 to 4, characterized in that The method for determining the cumulative oil production corresponding to the limit water cut according to the type A, type B, type C and type D water cut and cumulative production relationship curve comprises the following steps: The cumulative oil production corresponding to the limit water cut is calculated according to the type A, type B, type C and type D water cut and cumulative production relationship curve with the highest fitting accuracy and the smallest error, and the limit water cut is calculated to obtain the cumulative oil production corresponding to the limit water cut.

6. The ultra-high water-cut field recovery calibration method according to any one of claims 1 to 5, characterized in that The method for determining the calibrated recovery rate according to the cumulative oil production comprises the following steps: the cumulative oil production is divided by the geological reserves to obtain the calibrated recovery rate.

7. An ultra-high water cut field recovery calibration device, characterized by The method comprises the following steps: a limit water cut determination module for determining the limit water cut of the oilfield in the extra-high water cut stage according to the oilfield water-oil ratio and annual oil production relationship curve; a water cut and cumulative production curve module for determining the type A, type B, type C and type D water cut and cumulative production relationship curve according to the type A, type B, type C and type D water drive characteristic curve; a cumulative oil production determination module for determining the cumulative oil production corresponding to the limit water cut according to the type A, type B, type C and type D water cut and cumulative production relationship curve; a calibrated recovery rate determination module for determining the calibrated recovery rate according to the cumulative oil production.

8. A storage medium characterized by The storage medium has a computer program readable by a computer stored thereon, and the computer program is configured to execute the method for calibrating the recovery rate of the oilfield in the extra-high water cut stage according to any one of claims 1 to 6 when running.

9. An electronic device, characterized in that... The method comprises a processor and a memory, and the memory has a computer program stored therein, and the computer program is loaded and executed by the processor to realize the method for calibrating the recovery rate of the oilfield in the extra-high water cut stage according to any one of claims 1 to 6.

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