Calculation method for carbon dioxide output of oil well

Abstract

The invention relates to the technical field of carbon dioxide injection oil extraction, in particular to a method for calculating the amount of carbon dioxide produced by an oil well, which comprises the following steps of: calculating the oil sleeve annulus volume of the oil well in a carbon dioxide injection oil extraction test area based on the sleeve radius, the oil pipe radius and the height of a gas column in the oil sleeve annulus; calculating a first compression factor and a second compression factor corresponding to the first gas component based on the first wellhead temperature, the first annulus pressure, the second wellhead temperature and the second annulus pressure; on the basis of the second variable quantity and the testing duration, the instantaneous gas production rate of the carbon dioxide gas of the carbon dioxide injection oil extraction well in the testing process is calculated; the invention provides a method for calculating the carbon dioxide output of an oil well, which is suitable for oil reservoirs implementing carbon dioxide injection oil extraction technologies such as carbon dioxide flooding and carbon dioxide huff and puff, and can realize rapid calculation of the carbon dioxide injection oil extraction test area oil well output. And data support is provided for evaluating the carbon dioxide gas channeling condition of the oil well and calculating the carbon dioxide burying amount.

Description

Technical Field

[0001] The invention relates to the technical field of carbon dioxide injection oil production, and in particular to a method for calculating the amount of carbon dioxide produced by an oil well. Background Art

[0002] Carbon Dioxide Capture, Utilization and Storage (CCUS) refers to the process of separating carbon dioxide from industrial processes, energy utilization or the atmosphere, and directly utilizing it or injecting it into the formation to achieve permanent carbon dioxide emission reduction. In the oil industry, the main direction is CCUS-EOR (Enhanced Oil Recovery), which is to use the captured carbon dioxide for oil recovery and use the oil reservoir as a carbon storage body to achieve an industrial process that maximizes the coordinated development of carbon recovery and carbon storage. Carbon dioxide flooding and carbon dioxide throughput are currently one of the important CCUS-EOR technologies for improving oil recovery, with the advantages of good effect, quick results, economic and environmental protection, and wide applicability. At present, there are more than one hundred CCUS-EOR projects carried out worldwide. In the implementation of CCUS-EOR projects, how to achieve efficient measurement of oil well output gas is of great significance for guiding the evaluation of oil well carbon dioxide gas channeling and assisting in the calculation of carbon dioxide storage. Summary of the invention

[0003] The purpose of the present invention is to provide a method, device, equipment and medium for calculating the amount of carbon dioxide produced by an oil well, so as to improve the above technical problems.

[0004] In order to achieve the above objectives, the present application provides the following technical solutions:

[0005] The present application provides a method for calculating the amount of carbon dioxide produced by an oil well, the method comprising: obtaining a casing radius, a tubing radius, and a gas column height in an oil casing annulus of an oil well in a carbon dioxide injection oil production test area, and calculating the casing annulus volume of the oil well in the carbon dioxide injection oil production test area based on the casing radius, the tubing radius, and the gas column height in the oil casing annulus; obtaining a first wellhead temperature, a first annulus pressure, a second wellhead temperature, a second annulus pressure, and a first gas component generated in the carbon dioxide injection oil production oil well during a test, and calculating a first compression factor and a second compression factor corresponding to the first gas component based on the first wellhead temperature, the first annulus pressure, the second wellhead temperature, and the second annulus pressure, the first wellhead temperature and the first The annulus pressure is the wellhead temperature and annulus pressure of the carbon dioxide injection oil production well at the start of the test, the second wellhead temperature and the second annulus pressure are the wellhead temperature and the annulus pressure at the end of the test, and the first compression factor and the second compression factor correspond to the compression factor of the first produced gas under the two working conditions of starting the test and ending the test respectively; based on the casing annulus volume, the first compression factor and the second compression factor, the first change corresponding to the molar number of carbon dioxide gas in the casing annulus during the test is calculated, and the second change corresponding to the carbon dioxide gas volume is calculated based on the first change; based on the second change and the test duration, the instantaneous gas production of carbon dioxide gas in the carbon dioxide injection oil production well during the test is calculated.

[0006] Optionally, the casing annulus volume of the oil well in the carbon dioxide injection oil production test area is calculated based on the casing radius, the tubing radius and the gas column height in the casing annulus, including:

[0007] The casing radius, the tubing radius and the height of the gas column in the casing annulus are retrieved, and the casing annulus volume is calculated based on a first mathematical model, wherein the first mathematical model is:

[0008]

[0009] In the formula, r c is the casing radius, r t is the radius of the tubing, h is the height of the gas column in the casing annulus, V an is the casing annulus volume.

[0010] Optionally, based on the oil casing annulus volume, the first compression factor and the second compression factor, calculating a first change in the number of moles of carbon dioxide gas in the oil casing annulus during the test period includes:

[0011] Based on the casing annulus volume, the first compression factor and the second compression factor, the first variation is calculated by a second mathematical model, wherein the second mathematical model is:

[0012]

[0013] Where P1 is the first annulus pressure, P2 is the second annulus pressure, R is the universal gas constant of the produced gas, which is 8.314 J / (mol·K), T1 is the first wellhead temperature, T2 is the second wellhead temperature, and V an is the volume of the casing annulus, Z1 is the first compression factor, Z2 is the second compression factor, φ1 is the mole fraction of carbon dioxide in the produced gas at the beginning of the test, φ2 is the mole fraction of carbon dioxide in the produced gas at the end of the test, n 1CO2 is the number of moles of carbon dioxide gas in the casing annulus at the beginning of the test, n 2CO2 is the number of moles of carbon dioxide gas in the casing annulus at the end of the test, Δn CO2 It is the first change corresponding to the number of moles of carbon dioxide gas in the casing annulus during the test.

[0014] Optionally, calculating a second change amount corresponding to the volume of carbon dioxide gas based on the first change amount includes:

[0015] The second variation is calculated based on the variation by a third mathematical model, wherein the third mathematical model is:

[0016] ΔV CO2 =22.4×10 -3 ×Δn CO2 ;

[0017] In the formula, Δn CO2 is the first change in the number of moles of carbon dioxide gas in the casing annulus during the test, ΔV CO2 is the second change in the volume of carbon dioxide gas during the test.

[0018] Optionally, based on the second variation and the test duration, calculating the instantaneous gas production of carbon dioxide gas in the carbon dioxide injection oil production well during the test process includes:

[0019] Based on the second variation and the test duration, the instantaneous gas production is calculated by a fourth mathematical model, wherein the fourth mathematical model is:

[0020]

[0021] Where ΔV CO2 is the second change in the volume of carbon dioxide gas during the test, and Δt is the test duration.

[0022] In a second aspect, an embodiment of the present application provides a device for calculating the amount of carbon dioxide produced by an oil well, the device comprising a memory and a processor.

[0023] The memory is used to store computer programs; the processor is used to implement the steps of the above-mentioned method for calculating the amount of carbon dioxide produced by the oil well when executing the computer program.

[0024] In a third aspect, an embodiment of the present application provides a medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method for calculating the amount of carbon dioxide produced by an oil well are implemented.

[0025] The beneficial effects of the present invention are:

[0026] The invention provides a method for calculating the amount of carbon dioxide produced by an oil well. The method aims at the problems that, during the implementation of a carbon dioxide injection oil production project, the prior art uses instruments and equipment to measure the gas output of the oil well, which has a complex process flow and high cost, and the basic data required for calculating the output using an oil pipe gas mathematical model is difficult to obtain and the calculation process is complicated. A method for calculating the gas output of an oil well based on eight parameters that are easy to obtain on site, namely, casing diameter, oil pipe diameter, annular air column height, wellhead temperature (test start), wellhead temperature (test end), wellhead pressure (test start), wellhead pressure (test end) and test time of an oil well in a carbon dioxide injection oil production test area is established. The method realizes low-cost, rapid and efficient measurement of the gas output of an oil well produced by carbon dioxide injection, and is of great significance for guiding the evaluation of carbon dioxide gas channeling in oil wells and assisting in calculating the carbon dioxide storage amount.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a flow chart of a method for calculating the amount of carbon dioxide produced by an oil well described in an embodiment of the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of a device for calculating the amount of carbon dioxide produced by an oil well described in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals or letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment provides a method for calculating the amount of carbon dioxide produced by an oil well, and the method includes step S100, step S200, step S300 and step S400.

[0035] Step S100, obtaining the casing radius, tubing radius and gas column height in the casing annulus of the oil wells in the carbon dioxide injection oil production test area, and calculating the casing annulus volume of the oil wells in the carbon dioxide injection oil production test area based on the casing radius, tubing radius and gas column height in the casing annulus;

[0036] Step S200, obtaining a first wellhead temperature, a first annular pressure, a second wellhead temperature, a second annular pressure, and a first gas component generated in the carbon dioxide injection oil production well during the test, and calculating a first compression factor and a second compression factor corresponding to the first gas component based on the first wellhead temperature, the first annular pressure, the second wellhead temperature, and the second annular pressure, wherein the first wellhead temperature and the first annular pressure are the wellhead temperature and the annular pressure of the carbon dioxide injection oil production well at the start of the test, the second wellhead temperature and the second annular pressure are the wellhead temperature and the annular pressure at the end of the test, and the first compression factor and the second compression factor correspond to the compression factors of the first produced gas under the two working conditions of starting the test and ending the test, respectively;

[0037] Step S300, based on the oil casing annulus volume, the first compression factor and the second compression factor, calculate a first change in the number of moles of carbon dioxide gas in the oil casing annulus during the test period, and calculate a second change in the volume of carbon dioxide gas based on the first change;

[0038] Step S400: Based on the second variation and the test duration, the instantaneous gas production of the carbon dioxide gas in the carbon dioxide injection oil production well during the test is calculated.

[0039] Secondly, in step S100, the casing annulus volume of the oil well in the CO2 injection oil production test area is calculated based on the casing radius, the tubing radius and the gas column height in the casing annulus, including:

[0040] Step S110, retrieve the casing radius, tubing radius and gas column height in the casing annulus, and calculate the casing annulus volume based on a first mathematical model, wherein the first mathematical model is:

[0041]

[0042] In the formula, r c is the casing radius, r t is the radius of the tubing, h is the height of the gas column in the casing annulus, V an is the casing annulus volume.

[0043] Secondly, in step S300 of the present implementation, based on the oil casing annulus volume, the first compression factor and the second compression factor, the first change amount corresponding to the mole number of carbon dioxide gas in the oil casing annulus during the test period is calculated, including:

[0044] Step S310: Based on the casing annulus volume, the first compression factor and the second compression factor, the first variation is calculated by a second mathematical model, wherein the second mathematical model is:

[0045]

[0046] Where P1 is the first annulus pressure, P2 is the second annulus pressure, R is the universal gas constant of the produced gas, which is 8.314 J / (mol·K), T1 is the first wellhead temperature, T2 is the second wellhead temperature, and V an is the volume of the casing annulus, Z1 is the first compression factor, Z2 is the second compression factor, φ1 is the mole fraction of carbon dioxide in the produced gas at the beginning of the test, φ2 is the mole fraction of carbon dioxide in the produced gas at the end of the test, n 1CO2 is the number of moles of carbon dioxide gas in the casing annulus at the beginning of the test, n 2CO2 is the number of moles of carbon dioxide gas in the casing annulus at the end of the test, Δn CO2It is the first change corresponding to the number of moles of carbon dioxide gas in the casing annulus during the test.

[0047] Secondly, in step S300 of the present embodiment, the second change amount corresponding to the volume of carbon dioxide gas is calculated based on the first change amount, including:

[0048] Step S320: Calculate the second variation based on the variation by using a third mathematical model, wherein the third mathematical model is:

[0049] ΔV CO2 =22.4×10 -3 ×Δn CO2 ;

[0050] In the formula, Δn CO2 is the first change in the number of moles of carbon dioxide gas in the casing annulus during the test, ΔV CO2 is the second change in the volume of carbon dioxide gas during the test.

[0051] Secondly, in step S400 of the present embodiment, based on the second variation and the test duration, the instantaneous gas production of the carbon dioxide gas in the carbon dioxide injection oil production well during the test is calculated, including:

[0052] Step S410: Based on the second variation and the test duration, the instantaneous gas production is calculated by a fourth mathematical model, wherein the fourth mathematical model is:

[0053]

[0054] Where ΔV CO2 is the second change in the volume of carbon dioxide gas during the test, and Δt is the test duration.

[0055] In this embodiment, a method for calculating the amount of carbon dioxide produced by an oil well is provided. The method aims to solve the problems of complex on-site process flow and high cost in the prior art of measuring the gas output of an oil well using instruments and equipment during the implementation of a carbon dioxide injection oil production project, and the problem of difficulty in obtaining basic data required for calculating the output using an oil pipe gas mathematical model and a complex calculation process. A method for calculating the gas production of an oil well is established based on eight parameters that are easy to obtain on-site, namely, casing diameter, oil pipe diameter, annular air column height, wellhead temperature (test start), wellhead temperature (test end), wellhead pressure (test start), wellhead pressure (test end), and test time of an oil well in a carbon dioxide injection oil production test area. The method achieves low-cost, rapid, and efficient measurement of the gas production of an oil well produced by carbon dioxide injection, and is of great significance for guiding the evaluation of carbon dioxide gas crossover in oil wells and assisting in the calculation of carbon dioxide storage.

[0056] In summary, the overall implementation scheme of this embodiment is:

[0057] (1) Obtain relevant data parameters such as casing diameter, tubing diameter, annular air column height, wellhead temperature (test start), wellhead temperature (test end), wellhead pressure (test start), wellhead pressure (test end), mole fraction of carbon dioxide in produced gas (test start), mole fraction of carbon dioxide in produced gas (test end), and test time of the oil wells in the CO2 injection oil recovery test area.

[0058] (2) Based on the casing radius r c , tubing radius r t , the gas column height h in the casing annulus, and the volume V of the casing annulus in the CO2 injection oil production test area. an , the calculation formula is as follows:

[0059]

[0060] (3) The temperature, pressure and composition changes of the produced gas in the casing annulus during the production process of the oil wells in the CO2 injection oil production test area were measured. The wellhead temperature T1 and annulus pressure P1 of the CO2 injection oil production wells at the beginning of the test, as well as the wellhead temperature T2 and annulus pressure P2 at the end of the test were recorded. The gas composition of the produced gas at the beginning and end of the test was detected by a chromatograph. The mole fraction of carbon dioxide in the produced gas at the beginning and end of the test was recorded as φ1 and φ2, respectively.

[0061] (4) Based on the temperature and pressure (T1, P1) at the start of the test, the temperature and pressure (T2, P2) at the end of the test, and the gas composition of the produced gas, the corresponding produced gas compression factors Z1 and Z2 at the start and end of the test are calculated according to ISO 12213:2006 "Natural gas-Calculation of compression factor".

[0062] (5) The gas produced during the production process of the oil wells in the CO2 injection oil production test area is regarded as real gas, and the relevant parameters of the produced gas can be calculated using the real gas state equation. The state equation of the real gas is as follows:

[0063] PV=nZRT(2)

[0064] Wherein, P is the pressure of the produced gas, V is the volume of the produced gas, n is the number of moles of the produced gas, Z is the compression factor of the produced gas, R is the universal gas constant of the produced gas, and its value is 8.314 J / (mol·K), and T is the absolute temperature of the produced gas.

[0065] Ignoring the influence of temperature and pressure changes of oil wells in the CO2 injection oil production test area on the deformation of tubing and casing and the liquid level height in the casing annulus, that is, not considering the change in the casing annulus volume, the change in the number of moles of CO2 gas in the casing annulus at the beginning and end of the test can be obtained. The calculation formula is as follows:

[0066]

[0067] Where n 1CO2 is the number of moles of carbon dioxide gas in the casing annulus at the beginning of the test, n 2CO2 is the number of moles of carbon dioxide gas in the casing annulus at the end of the test, Δn CO2 It is the change in the number of moles of carbon dioxide gas in the casing annulus when the test starts and ends.

[0068] (6) Under standard conditions (20°C, 0.101 MPa), the volume of carbon dioxide gas per unit mole is 22.4 L. Therefore, the change in the volume of carbon dioxide gas ΔV can be calculated based on the change in the number of moles of carbon dioxide gas in the casing annulus at the beginning and end of the test. CO2 , the calculation formula is as follows:

[0069] ΔV CO2 =22.4×10 -3 ×Δn CO2 (4)

[0070] (7) Based on the time difference Δt between the start and end of the test and the change in the volume of carbon dioxide gas ΔV CO2 The instantaneous gas production Q of the carbon dioxide gas in the oil wells in the carbon dioxide injection oil production test area during the test can be calculated. CO2 .

[0071]

[0072] Example 2

[0073] In order to more clearly illustrate the method for calculating the amount of carbon dioxide produced by an oil well provided by the present invention, the specific implementation steps of the present invention are described by way of example:

[0074] (1) Obtain relevant parameter data such as casing diameter, tubing diameter, annular air column height, wellhead temperature (test start), wellhead temperature (test end), wellhead pressure (test start), wellhead pressure (test end), mole fraction of carbon dioxide in produced gas (test start), mole fraction of carbon dioxide in produced gas (test end), and test time of an oil well where carbon dioxide injection is carried out for oil production, as shown in Table 1.

[0075] Table 1. Data table of relevant parameters of oil wells produced by carbon dioxide injection

[0076]

[0077] (2) Referring to formula (1), according to the casing radius r of the CO2 injection oil well c , tubing radius r t , the gas column height h in the casing annulus, and the volume V of the casing annulus in the CO2 injection oil production well. an , the calculation process is as follows:

[0078]

[0079] (3) According to the temperature and pressure conditions (323.15K, 5MPa) at the beginning of the test and at the end of the test of the CO2 injection oil production well and the analysis results of the produced gas components, the corresponding produced gas compression factors Z1 and Z2 at the beginning of the test and at the end of the test were calculated to be 0.98032 and 0.98174 respectively.

[0080] (4) Referring to formula (3), the influence of temperature and pressure changes of the CO2-injected oil well on the deformation of the tubing and casing and the liquid level in the casing annulus is ignored, that is, the change in the volume of the casing annulus is not considered. The change in the number of moles of CO2 gas in the casing annulus at the beginning and the end of the test is calculated. The calculation process is as follows:

[0081]

[0082] (4) Referring to formula (4), the change in the volume of carbon dioxide gas ΔV is calculated based on the change in the number of moles of carbon dioxide gas in the casing annulus at the beginning and end of the test. CO2 , the calculation process is as follows:

[0083] ΔV CO2 =1.287×10 3 mol×22.4×10 -3 m 3 / mol=28.8288(m 3 )

[0084] (5) Referring to formula (5), based on the time difference Δt between the start and end of the test and the change in the volume of carbon dioxide gas ΔV CO2 Calculate the instantaneous gas production Q of the carbon dioxide gas in the oil well during the test. CO2 , the calculation process is as follows:

[0085]

[0086] Example 3

[0087] Corresponding to the above method embodiment, the embodiment of the present disclosure also provides a device for calculating the amount of carbon dioxide produced by an oil well. The device for calculating the amount of carbon dioxide produced by an oil well described below and the method for calculating the amount of carbon dioxide produced by an oil well described above can refer to each other.

[0088] Figure 2 FIG. 8 is a block diagram of a device 800 for calculating the amount of carbon dioxide produced by an oil well according to an exemplary embodiment. Figure 2 As shown, the electronic device 800 may include: a processor 801 and a memory 802. The electronic device 800 may also include one or more of a multimedia component 803, an I / O interface 804, and a communication component 805.

[0089] The processor 801 is used to control the overall operation of the electronic device 800 to complete all or part of the steps in the above-mentioned method for calculating the amount of carbon dioxide produced by the oil well. The memory 802 is used to store various types of data to support the operation of the electronic device 800, and these data may include, for example, instructions for any application or method used to operate on the electronic device 800, and application-related data, such as contact data, sent and received messages, pictures, audio, video, etc. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, referred to as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, referred to as EEPROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, referred to as EPROM), programmable read-only memory (Programmable Read-Only Memory, referred to as PROM), read-only memory (Read-Only Memory, referred to as ROM), magnetic memory, flash memory, disk or optical disk. The multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone, which is used to receive external audio signals. The received audio signal may be further stored in the memory 802 or sent through the communication component 805. The audio component also includes at least one speaker for outputting audio signals. The I / O interface 804 provides an interface between the processor 801 and other interface modules, and the above-mentioned other interface modules may be keyboards, mice, buttons, etc. These buttons may be virtual buttons or physical buttons. The communication component 805 is used for wired or wireless communication between the electronic device 800 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them, so the corresponding communication component 805 may include: Wi-Fi module, Bluetooth module, NFC module.

[0090] In an exemplary embodiment, the electronic device 800 can be implemented by one or more application specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), controllers, microcontrollers, microprocessors or other electronic components to execute the above-mentioned method for calculating the amount of carbon dioxide produced by oil wells.

[0091] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, and when the program instructions are executed by a processor, the steps of the above-mentioned method for calculating the amount of carbon dioxide produced by the oil well are implemented. For example, the computer-readable storage medium can be the above-mentioned memory 802 including program instructions, and the above-mentioned program instructions can be executed by the processor 801 of the electronic device 800 to complete the above-mentioned method for calculating the amount of carbon dioxide produced by the oil well.

[0092] Example 4

[0093] Corresponding to the above method embodiment, the embodiment of the present disclosure further provides a readable storage medium. The readable storage medium described below and the method for calculating the amount of carbon dioxide produced by an oil well described above can refer to each other.

[0094] A readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for calculating the amount of carbon dioxide produced by an oil well in the above method embodiment.

[0095] The readable storage medium may specifically be a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or other readable storage medium that can store program codes.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for calculating the amount of carbon dioxide produced by an oil well, characterized in that: The method comprises: The casing radius, tubing radius and gas column height in the casing annulus of the oil wells in the carbon dioxide injection oil production test area are obtained, and the casing annulus volume of the oil wells in the carbon dioxide injection oil production test area is calculated based on the casing radius, tubing radius and gas column height in the casing annulus; Obtaining a first wellhead temperature, a first annular pressure, a second wellhead temperature, a second annular pressure, and a first gas component generated in a carbon dioxide injection oil production well during a test, and calculating a first compression factor and a second compression factor corresponding to the first gas component based on the first wellhead temperature, the first annular pressure, the second wellhead temperature, and the second annular pressure, wherein the first wellhead temperature and the first annular pressure are the wellhead temperature and the annular pressure of the carbon dioxide injection oil production well at the start of the test, the second wellhead temperature and the second annular pressure are the wellhead temperature and the annular pressure at the end of the test, and the first compression factor and the second compression factor correspond to the compression factors of the first produced gas under two working conditions, namely, the start of the test and the end of the test; Based on the oil casing annulus volume, the first compression factor and the second compression factor, a first change amount corresponding to the number of moles of carbon dioxide gas in the oil casing annulus during the test period is calculated, and based on the first change amount, a second change amount corresponding to the volume of carbon dioxide gas is calculated; Based on the second variation and the test duration, the instantaneous gas production of the carbon dioxide gas in the carbon dioxide injection oil production well during the test is calculated.

2. The method for calculating the amount of carbon dioxide produced by an oil well according to claim 1, characterized in that: The casing annulus volume of the oil well in the carbon dioxide injection oil production test area is calculated based on the casing radius, the tubing radius and the gas column height in the casing annulus, including: The casing radius, the tubing radius and the height of the gas column in the casing annulus are retrieved, and the casing annulus volume is calculated based on a first mathematical model, wherein the first mathematical model is: In the formula, r c is the casing radius, r t is the radius of the tubing, h is the height of the gas column in the casing annulus, V an is the casing annulus volume.

3. The method for calculating the amount of carbon dioxide produced by an oil well according to claim 1, characterized in that: Based on the oil casing annulus volume, the first compression factor and the second compression factor, a first change amount corresponding to the mole number of carbon dioxide gas in the oil casing annulus during the test period is calculated, including: Based on the casing annulus volume, the first compression factor and the second compression factor, the first variation is calculated by a second mathematical model, wherein the second mathematical model is: Where P1 is the first annulus pressure, P2 is the second annulus pressure, R is the universal gas constant of the produced gas, which is 8.314 J / (mol·K), T1 is the first wellhead temperature, T2 is the second wellhead temperature, and V an is the volume of the casing annulus, Z1 is the first compression factor, Z2 is the second compression factor, φ1 is the mole fraction of carbon dioxide in the produced gas at the beginning of the test, φ2 is the mole fraction of carbon dioxide in the produced gas at the end of the test, n 1CO2 is the number of moles of carbon dioxide gas in the casing annulus at the beginning of the test, n 2CO2 is the number of moles of carbon dioxide gas in the casing annulus at the end of the test, Δn CO2 It is the first change corresponding to the number of moles of carbon dioxide gas in the casing annulus during the test.

4. The method for calculating the amount of carbon dioxide produced by an oil well according to claim 1, characterized in that: Calculating a second change amount corresponding to the volume of carbon dioxide gas based on the first change amount includes: The second variation is calculated based on the variation by a third mathematical model, wherein the third mathematical model is: ΔV CO2 =22.4×10 -3 ×Δn CO2 ; In the formula, Δn CO2 is the first change in the number of moles of carbon dioxide gas in the casing annulus during the test, ΔV CO2 It is the second change in the volume of carbon dioxide gas during the test.

5. The method for calculating the amount of carbon dioxide produced by an oil well according to claim 1, characterized in that: Based on the second variation and the test duration, the instantaneous gas production of the carbon dioxide gas in the carbon dioxide injection oil production well during the test is calculated, including: Based on the second variation and the test duration, the instantaneous gas production is calculated by a fourth mathematical model, wherein the fourth mathematical model is: Where ΔV CO2 is the second change in the volume of carbon dioxide gas during the test, and Δt is the test duration.

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