Method and device for calculating effective carbon dioxide storage capacity of constant-volume exhausted gas reservoir, computer storage medium and equipment

Abstract

The invention discloses a method for calculating the effective carbon dioxide storage capacity of a constant-volume depleted gas reservoir. The method comprises the following steps: collecting original geological reserves of a target gas reservoir, production dynamic data, original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant-volume depletion test data; establishing a relational expression between the pseudo-pressure and the accumulated natural gas equivalent yield in the corresponding period, then drawing a cross plot of the material balance relationship in the production stage of the target gas reservoir, and if the accumulated natural gas equivalent yield when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, determining that the gas reservoir is a constant-volume depleted gas reservoir; inquiring a CO2 deviation factor under the pressure and temperature of the original formation of the gas reservoir from CO2 injection, and calculating a mixed gas deviation factor under the pressure of the original formation of the gas reservoir from CO2 injection by utilizing the final recovery degree of the gas reservoir; calculating the injectable amount of CO2 injected from the exhausted gas reservoir to the original formation pressure of the gas reservoir; and calculating the CO2 effective storage capacity of the depleted gas reservoir. According to the method, the effective carbon dioxide storage capacity of the constant-volume exhausted gas reservoir can be reliably calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of geological storage of carbon dioxide, and in particular to a method, device, computer storage medium and equipment for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir based on actual test and production data. Background Art

[0002] As the world continues to increase its efforts to reduce greenhouse gas emissions, CCS (carbon capture and storage) has received more and more attention as a bottom-line guarantee for achieving net zero emissions worldwide. A large number of projects using depleted oil and gas reservoirs and saline aquifers for geological storage of carbon dioxide have been successfully implemented. Since natural gas has been effectively sealed for a long geological period, the gas reservoir has a high caprock integrity and fault sealing, and the development and production of gas reservoirs has a large amount of basic data and reusable ground production facilities. Therefore, using depleted gas reservoirs to store carbon dioxide is recognized as an economical and safe geological storage method.

[0003] Accurately understanding the storage capacity of the storage geological body is an important basis for source-sink matching planning and storage scheme design of CCS projects. Currently, the commonly used methods for calculating the carbon dioxide storage capacity of oil and gas reservoirs include the Carbon Leaders Forum method (Bachu, 2007) and the U.S. Department of Energy method (Goodman, 2011). However, these methods do not use the actual production data of oil and gas reservoirs for calculation, and the parameter reliability is poor. They can only be used to calculate the theoretical or maximum carbon dioxide storage capacity, and cannot be applied to the calculation of the effective carbon dioxide storage capacity of depleted gas reservoirs with a large amount of production data and at the end of development. There are currently published patents involving calculation methods for the storage capacity of depleted oil and gas reservoirs. For example, Chinese patent CN116502756 proposes a calculation method for calculating the theoretical maximum storage capacity of carbon dioxide in a fixed-volume closed oil reservoir, but this method is for calculating the theoretical maximum storage capacity, and due to the large difference in production performance between oil and gas reservoirs, this method cannot be applied to the calculation of the effective carbon dioxide storage capacity of depleted gas reservoirs. Chinese patent CN116562126 proposes an optimization design and system for geological storage parameters of carbon dioxide in depleted gas reservoirs. This method is mainly based on a large amount of gas reservoir geological and production data, and uses numerical simulation methods to design storage plans. It is suitable for the design of injection plans in the later stage of CCS projects. However, this method has high requirements on the quality and quantity of input data, and the simulation calculation is complex. It also has high requirements on reservoir expertise and simulation software operation, and cannot be applied to the rapid and effective evaluation of carbon dioxide storage capacity in depleted gas reservoirs.

[0004] Therefore, in view of the above shortcomings, it is necessary to provide a method that can quickly and accurately calculate the effective storage capacity of carbon dioxide in depleted gas reservoirs, so as to obtain reliable effective storage capacity of carbon dioxide and support the design of CCS project schemes. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for calculating the effective storage capacity of carbon dioxide in a constant-volume depleted gas reservoir, aiming to reliably calculate the effective storage capacity of carbon dioxide in a constant-volume depleted gas reservoir.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir, comprising the following steps:

[0008] Collect the original geological reserves of the target gas reservoir, production performance data, original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data, and determine the calculation parameters;

[0009] The formation pressure at different periods during the production process of the gas reservoir is obtained by using the production dynamic data, and the corresponding natural gas deviation factor is obtained by using the relationship between the deviation factor and the pressure established by the constant volume depletion test data, and the relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period is established, and then the intersection diagram of the material balance relationship of the target gas reservoir production stage is drawn. If the cumulative natural gas equivalent production when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, the influence of water invasion is excluded, and the gas reservoir is determined to be a constant volume depleted gas reservoir, and the next step is entered, otherwise the method ends;

[0010] Query the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected, and calculate the mixed gas deviation factor at the original formation pressure of the gas reservoir when CO2 is injected using the final recovery degree of the gas reservoir;

[0011] The injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir is calculated using the cumulative natural gas equivalent production, the original formation natural gas reserves and the mixed gas deviation factor at the original formation pressure of the gas reservoir when CO2 is injected;

[0012] The effective CO2 storage capacity of depleted gas reservoirs is calculated based on the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir.

[0013] As a preference, the calculation parameters include the cumulative natural gas production G under standard conditions i_gas , Cumulative condensate production under standard conditions G i_oil , Cumulative natural gas production under standard conditions G p_gas , Cumulative condensate production under standard conditions G p_oil , the density of condensate relative to pure water r oil , the molecular weight of condensate relative to pure water M oil ; Gas reservoir original formation pressure p i , gas reservoir original formation temperature T r and the natural gas deviation factor z at the original formation pressure and temperature of the gas reservoiri .

[0014] As a preferred embodiment, the relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period is as follows:

[0015]

[0016] In the formula, p gas is the formation pressure at different stages during gas reservoir exploitation; gas is the natural gas deviation factor at different stages in the gas reservoir production process; p gas / z gas is the pseudo pressure; G i is the original formation natural gas reserves; G p is the cumulative natural gas equivalent production.

[0017] As a preferred embodiment, the mixed gas deviation factor of the injected CO2 to the original formation pressure of the gas reservoir is calculated by the following formula:

[0018]

[0019] In the formula, z mix is the mixed gas deviation factor under the original formation pressure of CO2 injected into the gas reservoir; CO2 is the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected; R gas is the final recovery degree of the gas reservoir, which is calculated by the original formation natural gas equivalent reserves G i and cumulative natural gas equivalent production G p The ratio is determined.

[0020] As a preferred embodiment, the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir is calculated by the following formula:

[0021]

[0022] In the formula, G injCO2 The amount of CO2 that can be injected into a depleted gas reservoir to the original formation pressure of the gas reservoir; p mix is the formation pressure of the gas reservoir after CO2 injection, p mix =p i .

[0023] As a preferred embodiment, the effective CO2 storage capacity of the depleted gas reservoir is calculated by the following formula:

[0024]

[0025] In the formula, The effective storage capacity of CO2 in depleted gas reservoirs; is the density of CO2 under standard conditions.

[0026] In a second aspect, the present invention provides a device for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir, characterized by comprising:

[0027] The first processing unit is used to collect the original geological reserves of the target gas reservoir, production performance data, the original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data, and determine the calculation parameters;

[0028] The second processing unit is used to obtain the formation pressure at different periods during the production process of the gas reservoir using the production dynamic data, and obtain the corresponding natural gas deviation factor using the relationship between the deviation factor and the pressure established by the constant volume depletion test data, establish the relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period, and then draw the intersection diagram of the material balance relationship of the target gas reservoir production stage. If the cumulative natural gas equivalent production when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, the water invasion effect is excluded and the gas reservoir is determined to be a constant volume depleted gas reservoir;

[0029] The third processing unit is used to query the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when the CO2 is injected, and calculate the mixed gas deviation factor at the original formation pressure of the gas reservoir when the CO2 is injected using the final recovery degree of the gas reservoir;

[0030] The fourth processing unit is used to calculate the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir by using the cumulative natural gas equivalent production, the original formation natural gas reserves and the mixed gas deviation factor under the original formation pressure of the gas reservoir injected with CO2:

[0031] The fifth processing unit is used to calculate the effective storage capacity of CO2 in the depleted gas reservoir based on the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir.

[0032] In a third aspect, the present invention provides a computer-readable storage medium, characterized in that a computer program is stored therein, and the computer program is executed by a processor to control the device where the processor is located to implement the steps of the method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir as described in the first aspect of the present invention.

[0033] In a fourth aspect, the present invention provides a computer device, characterized in that it includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir as described in the first aspect of the present invention.

[0034] The present invention adopts the above technical solution, which has the following advantages:

[0035] The present invention establishes a method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir based on actual test and production data, establishes a functional relationship between the CO2 injection amount and the formation pressure, the gas deviation factor and the oil and gas production through the material balance principle, and provides a method for quickly calculating the deviation factor of the mixed gas after CO2 injection, which can reliably calculate the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0037] Figure 1 The cross-plot is the material balance relationship of the target gas reservoir during the production stage;

[0038] Figure 2 It is a cross-plot comparing the material balance relationship during the CO2 injection stage with the material balance relationship during the target gas reservoir production stage. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0040] The method for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir provided by the present invention comprises: collecting the original geological reserves of the target gas reservoir, production dynamic data, the original formation pressure and temperature of the gas reservoir, high pressure physical property analysis and constant volume exhaustion test data; establishing a relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period, and then drawing an intersection diagram of the material balance relationship in the production stage of the target gas reservoir, if the cumulative natural gas equivalent production when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, then the gas reservoir is determined to be a constant volume depleted gas reservoir; querying the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected, and calculating the mixed gas deviation factor at the original formation pressure of the gas reservoir by using the final recovery degree of the gas reservoir; calculating the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir; and calculating the effective storage capacity of CO2 in the depleted gas reservoir. The present invention can reliably calculate the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir.

[0041] The following is a detailed description of the method and device for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir provided by an embodiment of the present invention in conjunction with the accompanying drawings.

[0042] Embodiment 1:

[0043] This embodiment provides a method for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir, comprising the following steps:

[0044] S100. Collect the original geological reserves of the target gas reservoir, production dynamic data, original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data, and determine the calculation parameters; the calculation parameters include the cumulative natural gas production G under standard conditions. i_gas , Cumulative condensate production under standard conditions G i_oil , Cumulative natural gas production under standard conditions G p_gas , Cumulative condensate production under standard conditions G p_oil , the density of condensate relative to pure water r oil , the molecular weight of condensate relative to pure water M oil ; Gas reservoir original formation pressure p i , gas reservoir original formation temperature T r and the natural gas deviation factor z at the original formation pressure and temperature of the gas reservoir i .

[0045] S200. Use production dynamic data to obtain the formation pressure at different periods during the gas reservoir production process, and use the relationship between the deviation factor and pressure established by the constant volume depletion test data to obtain the corresponding natural gas deviation factor, and establish the pseudo pressure (i.e., p gas / z gas ) and the cumulative natural gas equivalent production in the corresponding period, and draw the intersection diagram of the material balance relationship of the target gas reservoir during the production stage. If the cumulative natural gas equivalent production when the pseudo pressure is equal to 0 is consistent with the original formation natural gas reserves, the influence of water invasion can be excluded, and the gas reservoir is determined to be a constant volume depleted gas reservoir, and the next step is entered, otherwise the method ends; where p gas / z gas The relationship with the cumulative natural gas equivalent production in the corresponding period is as follows:

[0046]

[0047] In the formula, p gas is the formation pressure at different stages during gas reservoir exploitation; gas is the natural gas deviation factor at different stages in the gas reservoir production process; G i is the original formation natural gas reserves; G p is the cumulative natural gas equivalent production.

[0048] Among them, the original formation natural gas reserves Gi and cumulative natural gas equivalent production G p Can be expressed as:

[0049]

[0050] S300. Query the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected, and calculate the mixed gas deviation factor at the original formation pressure of the gas reservoir when CO2 is injected by the following formula using the final recovery degree of the gas reservoir;

[0051]

[0052] In the formula, z mix is the mixed gas deviation factor under the original formation pressure of CO2 injected into the gas reservoir; CO2 is the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected; R gas is the final recovery degree of the gas reservoir, which is calculated by the original formation natural gas equivalent reserves G i and cumulative natural gas equivalent production G p The ratio is determined.

[0053] S400. Calculate the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir by using the cumulative natural gas equivalent production in step S200, the original formation natural gas reserves and the mixed gas deviation factor at the original formation pressure of the gas reservoir injected with CO2 in step S300 through the following formula:

[0054]

[0055] In the formula, G injCO2 The amount of CO2 that can be injected into a depleted gas reservoir to the original formation pressure of the gas reservoir; p mix is the formation pressure of the gas reservoir after CO2 injection, p mix =p i .

[0056] S500. Based on the injectable amount of CO2 to the original formation pressure of the depleted gas reservoir obtained in step S400, the effective CO2 storage capacity of the depleted gas reservoir is calculated by the following formula:

[0057]

[0058] In the formula, The effective storage capacity of CO2 in depleted gas reservoirs; is the density of CO2 under standard conditions.

[0059] In the above embodiment, preferably, the following steps may also be included:

[0060] S600. Calculate the CO2 injection from 0 to the injectable amount calculated in step S400 using the following formula (7): mix / z mix , draw p mix / z mix With G p -G injCO2 The intersection diagram is compared with the p in step S200. gas / z gas —G p The intersection diagrams are merged to further verify the reliability of the calculation results of the effective storage capacity of carbon dioxide in constant-volume depleted gas reservoirs. In theory, the trend lines of the two should be basically consistent.

[0061]

[0062] The following is a specific example to illustrate the method for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir of the present invention, which includes the following steps:

[0063] Step 1: The final shutdown time of the gas reservoir can be obtained based on the original geological reserves of the target gas reservoir, production performance data, original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data. i_gas , G i_oil , G p_gas , G p_oil 、p i , T r 、z i 、r oil 、M oil ; Using formula (2) and formula (3), the final shutdown time of the gas reservoir G i , G p , and through G p With G i The ratio can determine R gas The relevant calculation parameters determined are shown in Table 1.

[0064] Table 1 Calculation parameters

[0065]

[0066] Step 2: Use production dynamic data to obtain the formation pressure p at different stages during the gas reservoir production process gas , and the corresponding cumulative natural gas equivalent production G p , and the corresponding natural gas deviation factor z is obtained by using the relationship between the deviation factor and pressure established by the constant volume depletion test data gas , related data are shown in Table 2, and p gas / z gas The cumulative production of natural gas equivalent in the corresponding period G p and plot p gas / z gas With G p The intersection diagram (see Figure 1 ). gas / z gas With G p The fitting relationship is a linear relationship, p gas / z gas =0 when G p 16.01×10 8 m 3 , which is very close to the original geological reserves, with an error of 2%, indicating that the gas reservoir is a fixed-volume closed gas reservoir without water intrusion.

[0067] Table 2 Formation pressure, deviation factor and corresponding production of target gas reservoir during production stage

[0068]

[0069] Step 3: Query the original formation pressure p of the gas reservoir after injecting CO2 i and temperature T r CO2 deviation factor z under CO2 =0.5561. Formula (4) is used to calculate the mixed gas deviation factor z at the original formation pressure of the gas reservoir after CO2 injection after gas reservoir production is stopped. mix It is 0.6678.

[0070] Step 4: Use equation (5) to calculate the amount of CO2 that can be injected into the depleted gas reservoir to the original formation pressure of the gas reservoir. At this time, p mix =p i , we can get G injCO2 13.65×10 8 m 3 .

[0071] Step 5: Calculate the effective carbon dioxide storage capacity M of the depleted gas reservoir using formula (6) injCO2 2.5566 million tons, CO2 Take 1.873kg / m 3 .

[0072] Step 6: Use equation (7) to calculate the CO2 injection to 13.65×10 8 m 3 p mix / z mix , draw p mix / z mix With G p -G injCO2 Intersection diagram (G p G is the cumulative natural gas equivalent production when the gas reservoir is finally shut down p 9.67×10 8 m 3), and use the material balance fitting relationship of the gas reservoir production stage in step 2 to calculate the cumulative natural gas equivalent production G from the time of gas reservoir development to the final shutdown p 9.67×10 8 m 3 p gas / z gas , draw p in the same intersection diagram gas / z gas With G p Crossplot (see Figure 2 ). It can be seen that during the CO2 injection stage, p mix / z mix With G p -G injCO2 Relationship trend and gas reservoir production stage gas / z gas With G p The relationship trends are consistent, indicating that the CO2 calculation results of this constant volume depleted gas reservoir are reliable.

[0073] Embodiment 2:

[0074] The above-mentioned embodiment 1 provides a method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir. Correspondingly, this embodiment provides a device for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir. The calculation device provided in this embodiment can implement the calculation method of embodiment 1, and the calculation device can be implemented by software, hardware, or a combination of software and hardware. For example, the calculation device may include integrated or separate functional modules or functional units to execute the corresponding steps in each method of embodiment 1. Since the calculation device of this embodiment is basically similar to the method embodiment, the process described in this embodiment is relatively simple, and the relevant parts can refer to the partial description of embodiment 1. The calculation device of this embodiment is merely schematic.

[0075] The device for calculating the effective storage capacity of carbon dioxide in a constant-volume depleted gas reservoir provided in this embodiment includes:

[0076] The first processing unit is used to collect the original geological reserves of the target gas reservoir, production performance data, the original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data, and determine the calculation parameters;

[0077] The second processing unit is used to obtain the formation pressure at different periods during the production process of the gas reservoir using the production dynamic data, and obtain the corresponding natural gas deviation factor using the relationship between the deviation factor and the pressure established by the constant volume depletion test data, establish the relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period, and then draw the intersection diagram of the material balance relationship of the target gas reservoir production stage. If the cumulative natural gas equivalent production when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, the water invasion effect is excluded and the gas reservoir is determined to be a constant volume depleted gas reservoir;

[0078] The third processing unit is used to query the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when the CO2 is injected, and calculate the mixed gas deviation factor at the original formation pressure of the gas reservoir when the CO2 is injected using the final recovery degree of the gas reservoir;

[0079] The fourth processing unit is used to calculate the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir by using the cumulative natural gas equivalent production, the original formation natural gas reserves and the mixed gas deviation factor under the original formation pressure of the gas reservoir injected with CO2:

[0080] The fifth processing unit is used to calculate the effective storage capacity of CO2 in the depleted gas reservoir based on the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir.

[0081] Embodiment 3:

[0082] This embodiment provides a processing device for implementing the method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir provided in this embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of embodiment 1.

[0083] The processing device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The memory stores a computer program that can be run on the processor, and the processor executes the calculation method provided in this embodiment 1 when running the computer program.

[0084] Preferably, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0085] Preferably, the processor may be a central processing unit (CPU), a digital signal processor (DSP) or other general-purpose processors of various types, which are not limited here.

[0086] Embodiment 4:

[0087] The method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir of this embodiment 1 can be specifically implemented as a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing the method described in this embodiment 1.

[0088] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir, characterized in that: The following steps are involved: Collect the original geological reserves of the target gas reservoir, production performance data, original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data, and determine the calculation parameters; The formation pressure at different periods during the production process of the gas reservoir is obtained by using the production dynamic data, and the corresponding natural gas deviation factor is obtained by using the relationship between the deviation factor and the pressure established by the constant volume depletion test data, and the relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period is established, and then the intersection diagram of the material balance relationship of the target gas reservoir production stage is drawn. If the cumulative natural gas equivalent production when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, the influence of water invasion is excluded, and the gas reservoir is determined to be a constant volume depleted gas reservoir, and the next step is entered, otherwise the method ends; Query the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected, and calculate the mixed gas deviation factor at the original formation pressure of the gas reservoir when CO2 is injected using the final recovery degree of the gas reservoir; The injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir is calculated using the cumulative natural gas equivalent production, the original formation natural gas reserves and the mixed gas deviation factor at the original formation pressure of the gas reservoir when CO2 is injected; The effective CO2 storage capacity of depleted gas reservoirs is calculated based on the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir.

2. The calculation method according to claim 1, characterized in that: The calculation parameters include the cumulative natural gas production G under standard conditions i_gas , Cumulative condensate production under standard conditions G i_oil , Cumulative natural gas production under standard conditions G p_gas , Cumulative condensate production under standard conditions G p_oil , the density of condensate relative to pure water r oil , the molecular weight of condensate relative to pure water M oil ; Gas reservoir original formation pressure p i , gas reservoir original formation temperature T r and the natural gas deviation factor z at the original formation pressure and temperature of the gas reservoir i .

3. The calculation method according to claim 2, characterized in that: The relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period is as follows: In the formula, p gas is the formation pressure at different stages during gas reservoir exploitation; gas is the natural gas deviation factor at different stages in the gas reservoir production process; p gas / z gas is the pseudo pressure; G i is the original formation natural gas reserves; G p is the cumulative natural gas equivalent production.

4. The calculation method according to claim 3, characterized in that: The mixed gas deviation factor of the injected CO2 to the original formation pressure of the gas reservoir is calculated by the following formula: In the formula, z mix is the mixed gas deviation factor under the original formation pressure of CO2 injected into the gas reservoir; CO2 is the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when CO2 is injected; R gas is the final recovery degree of the gas reservoir, which is calculated by the original formation natural gas equivalent reserves G i and cumulative natural gas equivalent production G p The ratio is determined.

5. The calculation method according to claim 4, characterized in that: The injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir is calculated by the following formula: In the formula, G injCO2 The amount of CO2 that can be injected into a depleted gas reservoir to the original formation pressure of the gas reservoir; p mix is the formation pressure of the gas reservoir after CO2 injection, p mix =p i .

6. The calculation method according to claim 5, characterized in that: The effective storage capacity of CO2 in the depleted gas reservoir is calculated by the following formula: In the formula, The effective storage capacity of CO2 in depleted gas reservoirs; is the density of CO2 under standard conditions.

7. A device for calculating the effective storage capacity of carbon dioxide in a constant volume depleted gas reservoir, characterized in that: include: The first processing unit is used to collect the original geological reserves of the target gas reservoir, production performance data, the original formation pressure and temperature of the gas reservoir, high-pressure physical property analysis and constant volume depletion test data, and determine the calculation parameters; The second processing unit is used to obtain the formation pressure at different periods during the production process of the gas reservoir using the production dynamic data, and obtain the corresponding natural gas deviation factor using the relationship between the deviation factor and the pressure established by the constant volume depletion test data, establish the relationship between the pseudo-pressure and the cumulative natural gas equivalent production in the corresponding period, and then draw the intersection diagram of the material balance relationship of the target gas reservoir production stage. If the cumulative natural gas equivalent production when the pseudo-pressure is equal to 0 is consistent with the original formation natural gas reserves, the water invasion effect is excluded and the gas reservoir is determined to be a constant volume depleted gas reservoir; The third processing unit is used to query the CO2 deviation factor at the original formation pressure and temperature of the gas reservoir when the CO2 is injected, and calculate the mixed gas deviation factor at the original formation pressure of the gas reservoir when the CO2 is injected using the final recovery degree of the gas reservoir; The fourth processing unit is used to calculate the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir by using the cumulative natural gas equivalent production, the original formation natural gas reserves and the mixed gas deviation factor under the original formation pressure of the gas reservoir injected with CO2: The fifth processing unit is used to calculate the effective storage capacity of CO2 in the depleted gas reservoir based on the injectable amount of CO2 injected into the depleted gas reservoir to the original formation pressure of the gas reservoir.

8. A computer-readable storage medium, characterized in that: A computer program is stored, and the computer program is executed by a processor to control the device where the processor is located to implement the steps of the method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir as described in any one of claims 1 to 6.

9. 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 the processor implements the steps of the method for calculating the effective storage capacity of carbon dioxide in a fixed-volume depleted gas reservoir as described in any one of claims 1 to 6 when executing the computer program.

Images