Method and device for acquiring effective compressibility coefficient of oil reservoir, medium and equipment

Abstract

The invention discloses an oil reservoir effective compressibility coefficient obtaining method and device, a medium and equipment, and relates to the field of oil-gas field development, and the method comprises the steps of obtaining production data, water injection data and physical property parameters of a well; according to production data and water injection data of a well, the accumulated water injection rate and oil pressure of two rounds of water injection and the daily oil production between the two rounds of water injection are determined, the ratio of the accumulated water injection rate to the oil pressure is determined by conducting linear fitting on the accumulated water injection rate and the oil pressure, and the accumulated oil production between the two rounds of water injection is obtained by combining the daily oil production between the two rounds of water injection. Determining a water-oil ratio after water injection; based on the obtained physical property parameters and the water-oil ratio, the oil reservoir volume after water injection is determined, and the effective compressibility coefficient of the oil reservoir after water injection is accurately obtained by constructing a relational expression between the oil reservoir volume after water injection and the original oil reservoir volume, reserves and an original crude oil volume coefficient and a relation between the oil reservoir volume after water injection and oil reservoir material balance.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a method, device, medium and equipment for obtaining an effective compression coefficient of an oil reservoir. Background Art

[0002] The calculation of dynamic reserves of oil reservoirs is an indispensable link in the process of oil reservoir development. The calculation of dynamic reserves is mainly based on the material balance equation theory, and the effective compression coefficient of the oil reservoir is an important parameter of the material balance equation; the effective compression coefficient of the oil reservoir is related to the physical properties of rocks, crude oil and formation water, and is also affected by temperature and pressure. Water injection for oil replacement is to inject water into the oil reservoir to replace crude oil, so as to maintain or increase the oil layer pressure and increase the crude oil production; during the water injection for oil replacement process, the injection of water will increase the pore pressure, causing the rock skeleton to expand or compress, resulting in a change in the effective compression coefficient of the oil reservoir.

[0003] The calculation of the effective compression coefficient of conventional reservoirs only considers the volume changes of rock pores, bound water and formation water, and does not consider the impact of other factors on the effective compression coefficient of the reservoir after water injection, resulting in poor accuracy in obtaining the effective compression coefficient of the reservoir after water injection. Summary of the invention

[0004] The present invention provides a method, device, medium and equipment for obtaining an effective compression coefficient of an oil reservoir, which are used to solve the above-mentioned problem existing in the prior art, that is, how to improve the accuracy of obtaining the effective compression coefficient of an oil reservoir after water injection in the prior art. The present invention provides a method for obtaining an effective compression coefficient of an oil reservoir, which comprises: Obtain well production data, water injection data and physical property parameters; According to the production data and water injection data of the well, the cumulative water injection volume, oil pressure and daily oil production between the two rounds of water injection are determined. By linearly fitting the cumulative water injection volume and oil pressure, the ratio of the cumulative water injection volume and oil pressure is determined. Combined with the daily oil production between the two rounds of water injection, the cumulative oil production between the two rounds of water injection is obtained to determine the water-oil ratio after water injection; Determine the volume change of the reservoir after water injection based on the obtained physical parameters and water-oil ratio; According to the change of reservoir volume after water injection and the original reservoir volume, the reservoir volume after water injection is determined; The relationship between the reservoir volume after water injection and the original reservoir volume and reserves and the original crude oil volume coefficient, as well as the relationship between the reservoir volume after water injection and the reservoir material balance, are constructed to obtain the effective compression coefficient of the reservoir after water injection.

[0005] Optionally, determining the volume change of the reservoir after water injection based on the acquired physical property parameters and water-oil ratio specifically includes: When the reservoir pressure drops from the original formation pressure to the current formation pressure, the pore volume of the reservoir will decrease. The pore volume reduction is obtained by the following formula: ; When the reservoir pressure drops from the original formation pressure to the current formation pressure, the volume of water, injected water and bound water in the reservoir will expand. The following formula is used to obtain the bound water volume expansion: ; The water volume expansion is obtained using the following formula: ; After water injection, as the reservoir is produced, the reservoir pressure begins to drop and the volume of injected water expands. The following formula is used to obtain the volume expansion of injected water: ; Defining the water-oil ratio R wo is the volume of water in the reservoir or connected to it V w Oil-bearing reservoir volume V o The ratio is expressed as: ; The relationship between pore volume, original reservoir volume and irreducible water saturation is: ; According to the pore volume reduction, bound water volume expansion, water volume expansion and injected water volume expansion, combined with the defined water-oil ratio and the relationship between the void volume, the original reservoir volume and bound water saturation, the change in reservoir volume after water injection is obtained using the following formula: ; make ; The change in reservoir volume after water injection is: ; Among them, Δ V p Pore ​​volume reduction, V w is the volume of water in the reservoir or connected to it, Δ V WC is the volume expansion of bound water, V WC is the volume of bound water, Δ V W is the volume expansion of the water body, V WC is the volume of water, Δ Vinj is the volume expansion of injected water, V o is the oil-bearing reservoir volume, C p is the compression coefficient of rock, C w is the compressibility coefficient of formation water, S wc is the bound water saturation, Δp is the pressure drop, R wo is the water-oil ratio after water injection, B w is the volume coefficient of formation water, V p is the pore volume, V inj is the cumulative water injection volume, V ci is the original reservoir volume, C c is the reservoir volume compressibility factor considering the water-oil ratio.

[0006] Optionally, the determining the volume of the reservoir after water injection based on the volume change of the reservoir after water injection in combination with the original reservoir volume specifically includes: The reservoir volume after water injection is equal to the original reservoir volume minus the change in reservoir volume, which can be expressed as follows: ; The following formula is used to obtain the reservoir volume after water injection: ; in, V c is the reservoir volume after water injection, V ci is the original reservoir volume, Δ V is the change in reservoir volume, Δp is the pressure drop, B w is the volume coefficient of formation water, V inj is the cumulative water injection volume, C p is the compression coefficient of rock, C w is the compressibility coefficient of formation water, C c is the reservoir volume compressibility factor considering the water-oil ratio.

[0007] Optionally, the relationship between the original reservoir volume and reserves and the original crude oil volume coefficient specifically includes: ; in, N For reserves,B oi is the volume coefficient of the original crude oil, V ci is the original reservoir volume.

[0008] Optionally, the relationship between the reservoir volume after water injection and the reservoir material balance specifically includes: ; in, N For reserves, N p is the cumulative oil production, V c is the reservoir volume after water injection, B o is the volume coefficient of crude oil.

[0009] Optionally, obtaining the effective compressibility coefficient of the reservoir after water injection specifically includes: ; in, C c is the reservoir volume compressibility factor considering the water-oil ratio, C p is the rock compression coefficient, C w is the compressibility coefficient of formation water, Δp is the pressure drop, B w is the volume coefficient of formation water, V inj is the cumulative water injection volume, Δp is the pressure drop, N p is the cumulative oil production, B o is the volume coefficient of crude oil, C o is the compressibility coefficient of crude oil.

[0010] Also includes: The dynamic reserves are determined based on the flow material balance equation, and the flow material balance production indicator curve is used to verify the effective compressibility of the reservoir after water injection.

[0011] Optionally, determining the dynamic reserves according to the flow material balance equation specifically includes: ; in, t c To balance the time, t c =( N p B o + W pB w ) / q; N is the dynamic reserve, b pss is the coefficient under the quasi-steady flow state, Δp is the pressure drop, B oi is the original crude oil volume coefficient, q is the daily liquid production, C e is the effective compression coefficient of the reservoir after water injection to replace oil, N p is the cumulative oil production, B o is the volume coefficient of crude oil, W p is the cumulative water production, B w is the volume coefficient of formation water.

[0012] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method for obtaining the effective compression coefficient of an oil reservoir is implemented.

[0013] The present invention provides a computer device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for obtaining the effective compression coefficient of an oil reservoir when executing the program.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a method for obtaining the effective compression coefficient of an oil reservoir, which takes into account the influence of injected water on the effective compression coefficient of an oil reservoir on the basis of a conventional calculation formula for the effective compression coefficient of an oil reservoir, obtains the cumulative water injection volume, oil pressure and cumulative oil production of the well according to the production data and water injection data of the well, and obtains the water-oil ratio by linearly fitting the cumulative water injection volume and oil pressure of the well, and obtains a more accurate effective compression coefficient of the oil reservoir after water injection by taking into account the volume of the injected water and the volume change of the oil reservoir volume after water injection; in actual production processes, water injection is used to increase formation energy, and the injected water for replacing oil with water increases the pore pressure, causing the rock skeleton to expand or compress, thereby causing the effective compression coefficient of the oil reservoir to change accordingly; compared with the oil reservoir compression coefficient without considering water injection, the present invention can obtain a more realistic effective compression coefficient of the oil reservoir after water injection to replace oil, thereby effectively improving the accuracy of obtaining the effective compression coefficient of the oil reservoir after water injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] Figure 1A flow chart of a method for obtaining an effective compression coefficient of an oil reservoir provided by an embodiment of the present invention; Figure 2 A technical roadmap for calculating the effective compressibility factor of an oil reservoir provided by an embodiment of the present invention; Figure 3 A relationship diagram between the cumulative water injection volume and the oil pressure in the first round of water injection provided by an embodiment of the present invention; Figure 4 A relationship diagram between the cumulative water injection volume and the oil pressure of the second round of water injection provided by an embodiment of the present invention; Figure 5 A relationship diagram between the cumulative water injection volume and the oil pressure in the third round of water injection provided by an embodiment of the present invention; Figure 6 A relationship diagram between the cumulative water injection volume and the oil pressure in the fourth round of water injection provided by an embodiment of the present invention; Figure 7 This is a production indicator curve diagram of the flowing material balance method of Well A provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0019] Example 1 like Figure 1 and Figure 2 As shown, this embodiment shows a method for obtaining an effective compression coefficient of an oil reservoir, comprising: S1: Obtain well production data, water injection data and physical property parameters.

[0020] For example, the physical property parameters may include the crude oil compressibility coefficient C o , crude oil volume coefficient B o , rock compression coefficient C p and the formation water compressibility C w .

[0021] For example, an empirical formula of the formation water compressibility coefficient can be obtained based on the test data of the block, so as to calculate the formation water compressibility coefficient. The empirical formula of the formation water compressibility coefficient is: ; in, ; in, T is the formation temperature, P R is the formation pressure, R sw is the solubility of natural gas in formation water, C w is the formation water compressibility coefficient.

[0022] In this embodiment, T It can take 152°C, P R Take 105MPa, R sw Take 2m 3 / m 3 , according to the above empirical formula, calculate the formation water compressibility coefficient C w is 6.729×10 -4 MPa -1 .

[0023] For example, the crude oil compressibility coefficient is obtained based on PVT data and rock compressibility coefficient test results. C o and rock compressibility C p , the crude oil compressibility coefficient can be taken as C o is 47.33×10 -4 MPa -1 , rock compression coefficient C p 0.66×10 -4 MPa -1 .

[0024] S2: According to the production data and water injection data of the well, the cumulative water injection volume, oil pressure and daily oil production between the two rounds of water injection are determined. By linearly fitting the cumulative water injection volume and oil pressure, the ratio of the cumulative water injection volume and oil pressure is determined. Combined with the daily oil production between the two rounds of water injection, the cumulative oil production between the two rounds of water injection is obtained to determine the water-oil ratio after water injection.

[0025] For example, according to the water injection data, the cumulative water injection volume and oil pressure of each round of water injection in the four rounds of water injection are obtained, and the relationship between the cumulative water injection volume and the oil pressure is plotted with the cumulative water injection volume as the x value and the oil pressure as the y value, such as Figures 3 to 6 As shown, linear fitting is performed to obtain the slope of the straight line segment of the relationship diagram between the current and next rounds of water injection and oil pressure. K 1 and K 2. Then, based on the production dynamic data, the daily oil production between the two rounds of water injection is obtained, and the cumulative oil production between the two rounds of water injection is calculated. V o (m 3 ).

[0026] Optionally, the water-oil ratio after water injection is obtained using the following formula: ; in, B w is the volume coefficient of formation water, C w is the compressibility coefficient of formation water, Δ V o is the cumulative oil production, R wo is the water-oil ratio after water injection, K 1 is the slope of the straight line segment between the cumulative water injection volume and the oil pressure in this round, K 2 is the slope of the straight line segment between the cumulative water injection volume and oil pressure of the lower wheel, B o is the volume coefficient of crude oil.

[0027] In this embodiment, the volume coefficient of formation water is B w The volume coefficient of crude oil is 1.02. B o is 1.5831, as shown in Table 1, showing the water-oil ratio of Well A after each round of water injection. R wo .

[0028] Table 1 Water-oil ratio after each round of water injection in Well A R wo S3: Determine the volume change of the reservoir after water injection based on the obtained physical properties and water-oil ratio.

[0029] S4: Determine the volume of the reservoir after water injection based on the change in the reservoir volume after water injection and the original reservoir volume.

[0030] S5: Construct the relationship between the reservoir volume after water injection and the original reservoir volume and reserves and the original crude oil volume coefficient, as well as the relationship between the reservoir volume after water injection and the reservoir material balance, and obtain the effective compression coefficient of the reservoir after water injection.

[0031] The process of obtaining the effective compressibility coefficient of the reservoir after water injection is described in detail below.

[0032] For example, after water injection, the reservoir pressure drops from the original formation pressure to the current formation pressure, and the pore volume of the reservoir decreases, that is, the pore volume decreases by Δ V P for: ; in, V p is the pore volume, V w is the volume of water in the reservoir or connected to it, V inj is the cumulative water injection volume, C p is the compression coefficient of rock, and Δp is the pressure drop.

[0033] The reservoir drops from the original formation pressure to the current formation pressure, and the volume of water, injected water, and bound water in the reservoir expands; Bound water volume expansion Δ V WC for: ; in, V WC is the volume of bound water, C w is the compressibility coefficient of formation water.

[0034] Water volume expansion Δ V W for: ; After water injection, as the reservoir is produced, the reservoir pressure begins to drop, and the volume of injected water expands, that is, the volume expansion of injected water Δ V inj for: ; in, B w is the volume coefficient of formation water.

[0035] The pore volume of the reservoir will decrease, and the volume of water, injected water and bound water in the reservoir will expand, resulting in a decrease in the reservoir volume. That is, the change in the reservoir volume is: ; in, S wc is the bound water saturation.

[0036] By changing the water-oil ratio R wo Defined as the volume of water in or connected to a reservoir. V w Oil-bearing reservoir volume V o The specific calculation formula is as follows: ; According to the above-obtained pore volume reduction, bound water volume expansion, water volume expansion, injected water volume expansion and defined water-oil ratio, the change in reservoir volume can be obtained: ; in, C p is the compression coefficient of rock, C w is the compressibility coefficient of formation water, S wc is the bound water saturation, Δp is the pressure drop, R wo is the water-oil ratio after water injection, B w is the volume coefficient of formation water, V p is the pore volume, V inj is the cumulative water injection volume.

[0037] There is also a relationship between pore volume, original reservoir volume and irreducible water saturation: ; in, V p is the pore volume, V ci is the original reservoir volume.

[0038] Substituting the relationship between pore volume, original reservoir volume and irreducible water saturation into the reservoir volume change after sorting including the water-oil ratio, we can get: ; In order to facilitate the derivation of the subsequent reservoir effective compressibility formula, the reservoir volume compressibility factor considering the water-oil ratio is introduced. C c , the expression is as follows: ; in, C p is the compression coefficient of rock,C w is the compressibility coefficient of formation water, S wc is the bound water saturation, Δp is the pressure drop, R wo is the water-oil ratio after water injection.

[0039] The change in reservoir volume after water injection can be obtained: ; The reservoir volume will change after water injection. The reservoir volume after water injection is equal to the original reservoir volume minus the reservoir volume change. The specific calculation formula is as follows: ; Then the reservoir volume after water injection can be obtained V c for: ; According to reservoir engineering theory, the original reservoir and reserves can be obtained. N and the original crude oil volume coefficient B oi The relationship is: ; in, N For reserves, B oi is the volume coefficient of the original crude oil, V ci is the original reservoir volume.

[0040] From the basic form of reservoir material balance, we can get: ; in, N For reserves, N p is the cumulative oil production, V c is the reservoir volume after water injection, B o is the volume coefficient of crude oil.

[0041] Arranged: ; According to the relationship between the crude oil compressibility coefficient and the original crude oil volume coefficient, the current crude oil volume coefficient and the pressure drop, the specific calculation process is as follows: ; According to the elastic material balance equation: ; Arranged: ; Eliminating the pressure drop Δp on both sides, we can get: ; Finally, the effective compression coefficient of the reservoir after water injection is obtained: ; in, C c is the reservoir volume compressibility factor considering the water-oil ratio, C p is the rock compression coefficient, C w is the compressibility coefficient of formation water, Δp is the pressure drop, B w is the volume coefficient of formation water, V inj is the cumulative water injection volume, Δp is the pressure drop, N p is the cumulative oil production, B o is the volume coefficient of crude oil, C o is the compressibility coefficient of crude oil.

[0042] Effective compressibility of reservoir after water injection C e As shown in Table 2: Table 2 Effective compression coefficient of Well A after each round of water injection C e According to the effective compression coefficient after three rounds of water injection in Table 2, the average effective compression coefficient of the reservoir after three water injections can be obtained: .

[0043] Example 2 This embodiment compares the effective compression coefficient of the reservoir considering water injection with the compression coefficient of the reservoir not considering water injection, and determines the accuracy of the obtained effective compression coefficient of the reservoir considering water injection in combination with actual conditions.

[0044] Exemplarily, the effective compression coefficient of the reservoir without considering water injection is calculated using the calculation formula of the effective compression coefficient of the reservoir without considering water injection: ; in, C eff is the effective compressibility of the reservoir without considering water injection.

[0045] The specific calculation formula for calculating dynamic reserves based on the flow material balance equation is as follows: ; in,t c To balance the time, N is the dynamic reserve, b pss is the coefficient under the quasi-steady flow state, Δp is the pressure drop, B oi is the volume coefficient of the original crude oil, which can be taken as 1.9792, q is the daily liquid production, C e is the effective compression coefficient of the reservoir after water injection, which can be taken as 81.56×10 -4 MPa -1 .

[0046] Exemplary, equilibration time t c The expression can be ( N p B o + W p B w ) / q, where N p is the cumulative oil production, B o is the volume coefficient of crude oil, W p is the cumulative water production, B w is the volume coefficient of formation water.

[0047] According to the production dynamic data of Well A, the oil production, water production and oil pressure of Well A are obtained. t c is the X value, Δp / q is the Y value, and the flow material balance production indicator curve is drawn, such as Figure 7 As shown, the slope of the straight line segment is obtained K , whose slope K The expression is: ; According to the flow material balance production indicator curve of Well A, the slope of its straight line segment is K =0.0042, calculate the dynamic reserves of Well A N for: ; Without considering the effect of water injection on the effective compressibility coefficient of the reservoir, the dynamic reserves N of Well A is calculated as: ; The static geological model reserves of Well A obtained from the data provided by the oilfield unit are 1.3564×10 4t, comparing the two dynamic reserve calculation results, it can be seen that the dynamic reserve error considering the effect of water injection is 11.39%, and the dynamic reserve error without considering the effect of water injection is 80.40%. It can be seen that the effective compression coefficient of the reservoir calculated by this method is closer to the actual one, and the dynamic reserve error is smaller.

[0048] By comparing the effective compression coefficient of the reservoir with water injection and the reservoir compression coefficient without water injection, it is found that water injection increases the effective compression coefficient of the reservoir of this well. The reason is that water injection causes the reservoir skeleton to be shear-expanded, resulting in an increase in the effective compression coefficient of the reservoir. The calculated result is more in line with the actual situation.

[0049] Conventional calculation of effective compression coefficient of oil reservoir only considers the volume change of rock pores, bound water and formation water. In actual production process, water injection is used to increase formation energy. The injected water for water injection to replace oil will increase pore pressure, causing the rock skeleton to expand or compress, and the effective compression coefficient of oil reservoir will change accordingly. Conventional calculation formula of effective compression coefficient of oil reservoir is derived based on material balance equation, and material balance equation is universal and applicable to any complex oil reservoir. This method adds the influence of injected water on the effective compression coefficient of oil reservoir on the basis of conventional acquisition of effective compression coefficient of oil reservoir, so as to obtain the effective compression coefficient of oil reservoir after water injection to replace oil, which effectively improves the accuracy of obtaining effective compression coefficient of oil reservoir and is more in line with actual production.

[0050] The above is a method for obtaining the effective compression coefficient of an oil reservoir provided by one or more embodiments of this specification. Based on the same idea, this specification also provides a corresponding device for obtaining the effective compression coefficient of an oil reservoir, including: An acquisition module is used to obtain production data, water injection data and physical property parameters of the well; The water-oil ratio determination module is used to determine the cumulative water injection volume, oil pressure and daily oil production between two rounds of water injection according to the production data and water injection data of the well, determine the ratio of the cumulative water injection volume and oil pressure by linear fitting the cumulative water injection volume and oil pressure, obtain the cumulative oil production between the two rounds of water injection in combination with the daily oil production between the two rounds of water injection, and determine the water-oil ratio after water injection; A module for determining the volume change of the oil reservoir after water injection, which is used to determine the volume change of the oil reservoir after water injection based on the acquired physical property parameters and water-oil ratio; The post-water injection reservoir volume module is used to determine the post-water injection reservoir volume based on the post-water injection reservoir volume change and the original reservoir volume; The module for determining the effective compression coefficient of the reservoir after water injection is used to construct the relationship between the reservoir volume after water injection and the original reservoir volume and reserves and the original crude oil volume coefficient, as well as the relationship between the reservoir volume after water injection and the reservoir material balance, to obtain the effective compression coefficient of the reservoir after water injection.

[0051] The specific definition of the reservoir effective compression coefficient acquisition device can refer to the definition of the reservoir effective compression coefficient acquisition method mentioned above, which will not be repeated here. Each module in the above reservoir effective compression coefficient acquisition device can be implemented in whole or in part by software, hardware and a combination thereof. The above modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0052] The present invention also provides a computer-readable storage medium, which stores a computer program. The computer program can be used to execute the above-mentioned method for obtaining the effective compression coefficient of the oil reservoir.

[0053] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for obtaining the effective compression coefficient of the oil reservoir when executing the program.

[0054] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A method for obtaining an effective compression coefficient of an oil reservoir, characterized in that: include: Obtain well production data, water injection data and physical property parameters; According to the production data and water injection data of the well, the cumulative water injection volume, oil pressure and daily oil production between the two rounds of water injection are determined. By linearly fitting the cumulative water injection volume and oil pressure, the ratio of the cumulative water injection volume and oil pressure is determined. Combined with the daily oil production between the two rounds of water injection, the cumulative oil production between the two rounds of water injection is obtained to determine the water-oil ratio after water injection; Determine the volume change of the reservoir after water injection based on the obtained physical parameters and water-oil ratio; According to the change of reservoir volume after water injection and the original reservoir volume, the reservoir volume after water injection is determined; The relationship between the reservoir volume after water injection and the original reservoir volume and reserves and the original crude oil volume coefficient, as well as the relationship between the reservoir volume after water injection and the reservoir material balance, are constructed to obtain the effective compression coefficient of the reservoir after water injection.

2. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 1, characterized in that: The method of determining the volume change of the reservoir after water injection based on the obtained physical property parameters and water-oil ratio specifically includes: When the reservoir pressure drops from the original formation pressure to the current formation pressure, the pore volume of the reservoir will decrease. The pore volume reduction is obtained by the following formula: ； When the reservoir pressure drops from the original formation pressure to the current formation pressure, the volume of water, injected water and bound water in the reservoir will expand. The following formula is used to obtain the bound water volume expansion: ； The water volume expansion is obtained using the following formula: ； After water injection, as the reservoir is produced, the reservoir pressure begins to drop and the volume of injected water expands. The volume expansion of injected water is obtained using the following formula: ； The water-oil ratio is defined as the ratio of the volume of water in the reservoir or the water body connected to it to the volume of the oil-bearing reservoir. The expression is: ； The relationship between pore volume, original reservoir volume and irreducible water saturation is: ； According to the pore volume reduction, bound water volume expansion, water volume expansion and injected water volume expansion, combined with the defined water-oil ratio and the relationship between the void volume, the original reservoir volume and bound water saturation, the change in reservoir volume after water injection is obtained using the following formula: ； make ； The change in reservoir volume after water injection is: ； Among them, Δ V p Pore ​​volume reduction, V w is the volume of water in the reservoir or connected to it, Δ V WC is the volume expansion of bound water, V WC is the volume of bound water, Δ V W is the volume expansion of the water body, V WC is the volume of water, Δ V inj is the volume expansion of injected water, V o is the oil-bearing reservoir volume, C p is the compression coefficient of rock, C w is the compressibility coefficient of formation water, S wc is the bound water saturation, Δp is the pressure drop, R wo is the water-oil ratio after water injection, B w is the volume coefficient of formation water, V p is the pore volume, V inj is the cumulative water injection volume, V ci is the original reservoir volume, C c is the reservoir volume compressibility factor considering the water-oil ratio.

3. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 1, characterized in that: The method of determining the volume of the reservoir after water injection based on the volume change of the reservoir after water injection and the original reservoir volume specifically includes: The reservoir volume after water injection is equal to the original reservoir volume minus the change in reservoir volume, which can be expressed as follows: ； The following formula is used to obtain the reservoir volume after water injection: ； in, V c is the reservoir volume after water injection, V ci is the original reservoir volume, Δ V is the change in reservoir volume, Δp is the pressure drop, B w is the volume coefficient of formation water, V inj is the cumulative water injection volume, C p is the compression coefficient of rock, C w is the compressibility coefficient of formation water, C c is the reservoir volume compressibility factor considering the water-oil ratio.

4. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 1, characterized in that: The relationship between the original reservoir volume and reserves and the original crude oil volume coefficient specifically includes: ； in, N For reserves, B oi is the volume coefficient of the original crude oil, V ci is the original reservoir volume.

5. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 1, characterized in that: The relationship between the reservoir volume after water injection and the reservoir material balance specifically includes: ； in, N For reserves, N p is the cumulative oil production, V c is the reservoir volume after water injection, B o is the volume coefficient of crude oil.

6. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 2, characterized in that: The obtaining of the effective compression coefficient of the reservoir after water injection specifically includes: ; in, C c is the reservoir volume compressibility factor considering the water-oil ratio, C p is the rock compression coefficient, C w is the compressibility coefficient of formation water, Δp is the pressure drop, B w is the volume coefficient of formation water, V inj is the cumulative water injection volume, Δp is the pressure drop, N p is the cumulative oil production, B o is the volume coefficient of crude oil, C o is the compressibility coefficient of crude oil.

7. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 1, characterized in that: The method further comprises: The dynamic reserves are determined based on the flow material balance equation, and the flow material balance production indicator curve is used to verify the effective compressibility of the reservoir after water injection.

8. The method for obtaining the effective compressibility coefficient of an oil reservoir according to claim 7, characterized in that: Determining the dynamic reserves according to the flow material balance equation specifically includes: ； in, t c To balance the time, t c =( N p B o + W p B w ) / q; N is the dynamic reserve, b pss is the coefficient under the quasi-steady flow state, Δp is the pressure drop, B oi is the original crude oil volume coefficient, q is the daily liquid production, C e is the effective compression coefficient of the reservoir after water injection to replace oil, N p is the cumulative oil production, B o is the volume coefficient of crude oil, W p is the cumulative water production, B w is the volume coefficient of formation water.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method for obtaining the effective compression coefficient of an oil reservoir as described in any one of claims 1 to 8 is implemented.

10. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for obtaining the effective compression coefficient of the oil reservoir as claimed in any one of claims 1 to 8 is implemented.

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