A method of correcting total porosity for light oil reservoirs and related apparatus

Abstract

The application discloses a method for correcting total porosity of light oil reservoir and related device, and belongs to the technical field of petroleum logging engineering; first, the total porosity of the core under the ground environment is measured, then the porosity lost due to the change of the environmental temperature and pressure from the moment of drilling to the moment of full-diameter core nuclear magnetic resonance measurement is combined with drilling coring (closed coring) to analyze the oil swelling overflow porosity and gas overflow porosity in the core drilling-ground measurement process, and the total porosity reduction is calculated; thus, the total porosity of the reservoir is calculated by combining the previously measured total porosity of the core, and the correction of the porosity is completed. The application can accurately calculate the real total porosity of the core at the moment of drilling and other reservoir key parameters, and provides key data support for reservoir evaluation.

Description

Technical Field

[0001] This invention belongs to the field of petroleum logging engineering technology, and relates to a method and related apparatus for correcting the total porosity of light oil reservoirs. Background Technology

[0002] As the calculation of reserves in complex gas reservoirs such as shale oil and tight oil is one of the goals of oil and gas field exploration and development, the quantitative calculation of the physical properties, pore structure, and gas saturation of such reservoirs is one of the difficulties in oil field exploration, development, and well logging evaluation.

[0003] Currently, data for light (volatile) reservoirs is mainly obtained through in-situ logging for qualitative identification, well logging data, and laboratory core experiments. However, in-situ logging can only evaluate lithology and oil-bearing grade of the core sample; the applicability of the method for calculating relevant parameters of light (volatile) reservoirs using well logging data needs further verification; laboratory core experiments require drilling plunger samples, and the experimental results are point-based data, which are discontinuous and cannot fully reflect the fluid composition characteristics under undisturbed formation conditions, thus severely reducing the reliability of reservoir evaluation. The application technology of full-diameter core two-dimensional nuclear magnetic resonance (NMR) in-situ measurement and evaluation has developed rapidly. It enables non-destructive and rapid measurement of cores immediately after extraction from the wellbore, acquiring one-dimensional T2 and two-dimensional T1-T2 NMR relaxation signals. This allows for rapid, continuous, non-destructive, large-volume, and high-precision one-dimensional T2 and two-dimensional T1-T2 NMR measurements and rapid data processing and interpretation on freshly extracted cores at the well site. This not only enables timely qualitative evaluation of reservoir fluid properties at the well site but also allows for the acquisition of quantitative reservoir parameters such as formation porosity, pore structure, and oil saturation. Significant application results have been achieved through exploration and development practices, making it a new and important technical means for evaluating shale oil, tight oil, and complex clastic rock reservoirs.

[0004] However, for light (volatile) oil reservoirs, during the process from core drilling to surface measurement, changes in temperature and pressure cause the fluid in the core to diffuse and volatilize, resulting in a lower-than-expected porosity in the field measurements. Therefore, there is an urgent need to develop a method to correct the total porosity of light oil reservoirs. Summary of the Invention

[0005] This invention provides a method and related apparatus for correcting the total porosity of light oil reservoirs, in order to solve the technical problem that the porosity measured by the prior art is inaccurate and is lower than the actual value.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a method for correcting the total porosity of a light oil reservoir, comprising the following steps:

[0008] The total porosity of the core under surface conditions was measured, and the original formation pressure, bubble point pressure, gas-bearing porosity of the core and gas-bearing porosity measured under surface conditions were obtained.

[0009] The crude oil expansion overflow porosity is calculated based on the original formation pressure and bubble point pressure; the gas overflow porosity is calculated based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions, thus obtaining the total porosity reduction.

[0010] The corrected total porosity of the reservoir is calculated based on the total porosity of the core and the reduction in total porosity.

[0011] Furthermore, the step of measuring the total porosity of the core under ground conditions specifically includes: using full-diameter core nuclear magnetic resonance technology to measure the total porosity Φ of the core under ground conditions.

[0012] Furthermore, the step of calculating the crude oil expansion porosity based on the original formation pressure and bubble point pressure specifically includes:

[0013] Based on the compressibility coefficient Co of crude oil in the formation of the area to be tested, the volume factor Bob of crude oil under bubble point pressure is calculated.

[0014] Hydrogen atom loss was calculated using the crude oil volume factor Bob at bubble point pressure and the original formation crude oil volume factor Bo; the specific calculation formula is as follows:

[0015] ΔHI=(Bob-Bo) / Bob

[0016] Where ΔHI represents the amount of hydrogen atoms lost;

[0017] The porosity ΔΦo of crude oil expansion overflow is calculated based on the amount of hydrogen atoms lost and the original amount of hydrogen atoms.

[0018] Furthermore, the relationship between the volume factor Bob of the crude oil at the bubble point pressure and the compressibility factor Co of the crude oil is as follows:

[0019]

[0020] Where Co is the formation oil compressibility coefficient; Bo is the original formation oil volume coefficient; Bob is the oil volume coefficient at bubble point pressure; P is the original formation pressure; and Pb is the bubble point pressure.

[0021] Furthermore, the specific calculation formula for the step of calculating the gas overflow porosity based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions is as follows:

[0022] ΔΦo'=Φg-Φgc

[0023] Wherein, ΔΦo' is the gas overflow porosity; Φg is the gas-bearing porosity of the core, and the size of Φg is (1-1 / Bo) times the original oil-bearing porosity; Φgc is the gas-bearing porosity measured under ground conditions.

[0024] Furthermore, the formula for calculating the total porosity reduction ΔΦ is as follows:

[0025] ΔΦ=ΔΦo+ΔΦo'

[0026] Where ΔΦo is the porosity of crude oil expansion overflow; ΔΦo' is the porosity of gas overflow.

[0027] Furthermore, the specific calculation formula for the step of calculating the corrected total reservoir porosity based on the total core porosity and the reduction in total porosity is as follows:

[0028] Φ'=Φ-ΔΦ

[0029] Where Φ' is the corrected total reservoir porosity; Φ is the total core porosity; and ΔΦ is the reduction in total porosity.

[0030] Secondly, the present invention provides a system for correcting the total porosity of light oil reservoirs, comprising:

[0031] The porosity measurement module is used to measure the total porosity of core samples under surface conditions and to obtain the original formation pressure, bubble point pressure, gas-bearing porosity of the core sample, and gas-bearing porosity measured under surface conditions.

[0032] The reduction calculation module is used to calculate the crude oil expansion overflow porosity based on the original formation pressure and bubble point pressure; and to calculate the gas overflow porosity based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions, thereby obtaining the total porosity reduction.

[0033] The correction module is used to calculate the corrected total porosity of the reservoir based on the total porosity of the core and the reduction in total porosity.

[0034] Thirdly, the present invention 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 executes the computer program to implement the steps of the method described above.

[0035] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method described above.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] This invention discloses a method and related apparatus for correcting the total porosity of light oil reservoirs. First, the total porosity of the core under surface conditions is measured. Then, considering the porosity loss due to changes in environmental temperature and pressure during the process from drilling (closed core sampling) to full-diameter core NMR measurement, the porosity loss due to crude oil expansion and gas overflow during the core drilling-surface measurement process is analyzed, and the reduction in total porosity is calculated. Based on the previously measured total core porosity, the total reservoir porosity is calculated, completing the porosity correction. This invention can accurately calculate the true total porosity and other key reservoir parameters at the time of drilling, providing crucial data support for reservoir evaluation. It offers a novel method for obtaining key parameters such as the true total porosity of light (volatile) oil reservoirs in shale oil and tight oil fields through full-diameter core NMR measurement.

[0038] Furthermore, this invention rapidly obtains porosity and pore structure information of light (volatile) oil reservoirs under surface measurement conditions through full-diameter core nuclear magnetic resonance field measurement, and can also quickly qualitatively identify reservoir fluid properties and quantitatively calculate parameters such as oil saturation.

[0039] Furthermore, this invention, through detailed analysis of the changes in temperature and pressure environment during the core drilling and surface measurement process, causes the fluid in the core to diffuse and volatilize, effectively calculating the lost hydrogen nuclei content during this process, thereby accurately calculating the porosity of crude oil expansion and overflow. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart of the method according to an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the system according to an embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram illustrating the entire process of core drilling and surface measurement of hydrogen nucleus loss according to an embodiment of the present invention.

[0044] Figure 4 This is a graph showing the relationship between Bo, Bt (two-phase volume coefficient of oil and gas) and p in underground crude oil according to an embodiment of the present invention;

[0045] Figure 5 This is an NMR result of the porosity after restoration according to an embodiment of the present invention;

[0046] Figure 6 This is a schematic diagram of the computer device structure of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0052] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0053] The present invention will now be described in further detail with reference to the accompanying drawings:

[0054] See Figure 1 This invention discloses a method for correcting the total porosity of light oil reservoirs, comprising the following steps:

[0055] Step 1: Measure the total porosity of the core under terrestrial conditions;

[0056] In this step, the total porosity Φ of the core under ground conditions is measured using full-diameter core nuclear magnetic resonance technology.

[0057] Step 2,

[0058] The crude oil expansion overflow porosity is calculated based on the original formation pressure and bubble point pressure; the gas overflow porosity is calculated based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions, thus obtaining the total porosity reduction.

[0059] Step 2.1, the calculation process of crude oil expansion overflow porosity, includes the following steps:

[0060] Based on the compressibility coefficient Co of crude oil in the formation of the area to be tested, the volume factor Bob of crude oil at the bubble point pressure is calculated; when P>Pb, the relationship between the compressibility coefficient Co and the volume factor Bob of crude oil at the bubble point pressure is as follows:

[0061]

[0062] Where Co is the formation oil compressibility coefficient; Bo is the original formation oil volume coefficient; Bob is the oil volume coefficient at bubble point pressure; P is the original formation pressure; and Pb is the bubble point pressure.

[0063] When P = Pb, within a fixed pore volume, the crude oil volume expansion overflow Mp can be calculated using the crude oil volume factor Bob at the bubble point pressure and the original formation crude oil volume factor Bo; the specific calculation formula is as follows:

[0064] Mp=(Bob-Bo) / Bob*M

[0065] Where M is the molecular weight of crude oil of the same volume under formation conditions;

[0066] From the above formula, the amount of hydrogen atom loss is:

[0067] ΔHI=(Bob-Bo) / Bob

[0068] Where ΔHI represents the amount of hydrogen atoms lost;

[0069] The porosity ΔΦo of crude oil expansion is calculated based on the amount of hydrogen atoms lost and the original amount of hydrogen atoms; the ratio of the amount of hydrogen atoms lost to the original amount of hydrogen atoms is the porosity ΔΦo of crude oil expansion.

[0070] Step 2.2, the calculation process of gas overflow porosity, includes the following steps:

[0071] Given that the two-phase volume coefficient Bt of oil and gas is:

[0072] Bt=Bo+(Rsi-Rs)Bg

[0073] Where Bt is the two-phase volume factor of oil and gas; Rsi is the original gas-oil ratio; Rs is the dissolved gas-oil ratio; Bg is the gas phase volume factor; and Bo is the original formation crude oil volume factor.

[0074] When the formation pressure drops to atmospheric pressure at the surface, all dissolved gas escapes, and Bt reaches its maximum value. When the core pore pressure drops to 0.101 MPa, the remaining oil-bearing pore volume in the core pore space is 1 / Bo times the original oil-bearing pore volume. The vacated original oil-bearing pores are filled with gas, meaning the gas-bearing porosity Φg is (1-1 / Bo) times the original oil-bearing porosity. Under one atmosphere of pressure, the hydrogen content index HIg of hydrocarbon gases in the pores is extremely low and can be ignored (undetectable by instruments).

[0075] The specific formula for calculating the gas overflow porosity ΔΦo' is as follows:

[0076] ΔΦo'=Φg-Φgc

[0077] Wherein, ΔΦo' is the gas overflow porosity; Φg is the gas-bearing porosity of the core, and the size of Φg is (1-1 / Bo) times the original oil-bearing porosity; Φgc is the gas-bearing porosity measured under ground conditions.

[0078] Step 2.3, the formula for calculating the total porosity reduction ΔΦ is as follows:

[0079] ΔΦ=ΔΦo+ΔΦo'

[0080] Where ΔΦo is the porosity of crude oil expansion overflow; ΔΦo' is the porosity of gas overflow.

[0081] Step 3: Calculate the corrected total reservoir porosity based on the total core porosity and the reduction in total porosity. The specific calculation formula is as follows:

[0082] Φ'=Φ-ΔΦ

[0083] Where Φ' is the corrected total reservoir porosity; Φ is the total core porosity; and ΔΦ is the reduction in total porosity.

[0084] See Figure 2 This invention discloses a system for correcting the total porosity of light oil reservoirs, comprising a porosity measurement module, a reduction calculation module, and a correction module connected in sequence.

[0085] The porosity measurement module is used to measure the total porosity of the core under ground conditions and to obtain the original formation pressure, bubble point pressure, gas-bearing porosity of the core, and gas-bearing porosity measured under ground conditions.

[0086] The reduction calculation module is used to calculate the crude oil expansion overflow porosity based on the original formation pressure and bubble point pressure; and to calculate the gas overflow porosity based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions, thereby obtaining the total porosity reduction.

[0087] In this module, the porosity of the crude oil due to expansion is first calculated. Given the compressibility coefficient Co of the crude oil in the formation, the volume factor Bob of the crude oil at the bubble point pressure can be calculated. This is done using the following formula:

[0088]

[0089] Where Co is the formation oil compressibility coefficient; Bo is the original formation oil volume coefficient; Bob is the oil volume coefficient at bubble point pressure; P is the original formation pressure; and Pb is the bubble point pressure.

[0090] The hydrogen atom loss (hydrogen-containing exponential reduction) was then calculated using the original formation crude oil volume factor Bo and the crude oil volume factor Bob at the bubble point pressure:

[0091] ΔHI=(Bob-Bo) / Bob

[0092] Where ΔHI represents the amount of hydrogen atoms lost;

[0093] The porosity ΔΦo of crude oil expansion overflow is calculated based on the amount of hydrogen atom loss (including the reduction in hydrogen index) and the original amount of hydrogen atoms.

[0094] Secondly, the gas overflow porosity ΔΦo' is calculated using the following formula:

[0095] ΔΦo'=Φg-Φgc

[0096] wherein, ΔΦo' is the gas overflow porosity; Φg is the gas-bearing porosity of the core, and the value of Φg is (1-1 / Bo) times the original oil-bearing porosity; Φgc is the gas-bearing porosity measured under surface conditions.

[0097] Finally, the total porosity reduction ΔΦ is calculated, and the specific calculation formula is:

[0098] ΔΦ=ΔΦo+ΔΦo'

[0099] wherein, ΔΦo is the crude oil expansion overflow porosity; ΔΦo' is the gas overflow porosity.

[0100] The correction module is configured to calculate the corrected total reservoir porosity according to the total core porosity and the total porosity reduction. The specific calculation formula is:

[0101] Φ'=Φ-ΔΦ

[0102] wherein, Φ' is the corrected total reservoir porosity; Φ is the total core porosity; ΔΦ is the total porosity reduction.

[0103] See Figure 6 , an embodiment of the present invention discloses a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for correcting total porosity of a light oil reservoir are implemented.

[0104] An embodiment of the present invention discloses a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the steps of the method for correcting total porosity of a light oil reservoir are implemented.

[0105] The working principle of the present invention is as follows:

[0106] (1) According to the characteristics of light oil reservoirs, the whole process of drilling-pulling out-surface coring-measurement is divided into four stages.

[0107] (2) Stage A: the core is drilled and pulled up to the position where the hydrostatic column pressure equals the formation pressure for coring, that is, the stage where (core pore pressure) Pc < Pf (hydrostatic column pressure). For pressure coring, the sealing fluid effectively prevents the core from being contaminated by drilling fluid. When the temperature is high and the pressure difference is large, light oil has a certain volume compression, and the sealing fluid or drilling fluid filtrate may invade the area near the core surface layer. (See Figure 3 )

[0108] (3) When the core is lifted to a position where the hydrostatic column pressure is equal to the bubble point (saturation) pressure, that is, in the stage where Pc≥Pf≥Pb (bubble point pressure at the corresponding temperature), the pore fluid in the core still maintains a single-phase fluid state. As the pressure decreases, the volume of crude oil expands, and the expanded part leaves the core (i.e., escapes). The greater the pressure difference between formation pressure and bubble point pressure is, the greater the volume expansion of crude oil is, and the greater the escape amount is. This is the downhole pressure drop→crude oil (expansion) diffusion stage. (see Figure 3 )

[0109] (4) Before the core reaches the surface and is brought out of the barrel, that is, in the stage where Pf<Pc≤Pb, the pore fluid in the core (near the surface) begins to present an oil-gas two-phase state, and the whole process is still a pressure drop diffusion stage. (see Figure 3 )

[0110] (5) From when the core is taken out of the barrel to when the measurement is completed, the core is exposed to the surface environment, and two escape states occur: pressure drop diffusion and concentration diffusion (volatilization). The superposition of the two accelerates fluid escape. (see Figure 3 )

[0111] (6) The escape of light oil is mainly divided into crude oil escape part and gas-bearing porosity escape part. (see Figure 4 )

[0112] For the crude oil escape part, the porosity of expanded and overflowed crude oil ΔΦo is calculated through the reduction of hydrogen index; for the gas-bearing porosity escape part, the porosity of overflowed gas is calculated by means of the gas-bearing porosity Φg of the core and the gas-bearing porosity Φgc measured on the ground.

[0113] (7) Therefore, the reduction of total nuclear magnetic porosity is: ΔΦ=ΔΦo+ΔΦo’

[0114] wherein, ΔΦo is the porosity of crude oil expanded and overflowed; ΔΦo’ is the porosity of gas overflowed.

[0115] (8) Under the conditions of different formation temperatures and pressures in each stage, the porosity lost due to volume expansion and degassing expansion diffusion of downhole core crude oil is calculated according to the properties of formation crude oil and associated gas components, and a system for restoring total formation porosity is established based on this, so as to restore the true formation porosity (see Table 1 below and Figure 5 )

[0116]

[0117]

[0118] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0119] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0120] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0121] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for correcting the total porosity of light oil reservoirs, characterized in that, Includes the following steps: The total porosity of the core under surface conditions was measured, and the original formation pressure, bubble point pressure, gas-bearing porosity of the core and gas-bearing porosity measured under surface conditions were obtained. The crude oil expansion overflow porosity is calculated based on the original formation pressure and bubble point pressure; the gas overflow porosity is calculated based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions, thus obtaining the total porosity reduction. The corrected total reservoir porosity was calculated based on the total porosity of the core and the reduction in total porosity. The step of calculating the crude oil expansion porosity based on the original formation pressure and bubble point pressure specifically includes: Based on the compressibility coefficient Co of crude oil in the formation of the area to be tested, the volume factor Bob of crude oil under bubble point pressure is calculated. Hydrogen atom loss was calculated using the crude oil volume factor Bob at bubble point pressure and the original formation crude oil volume factor Bo; the specific calculation formula is as follows: in, HI represents the amount of hydrogen atoms lost. The porosity of crude oil expansion and overflow was calculated based on the amount of hydrogen atoms lost and the original amount of hydrogen atoms. Φo.

2. The method for correcting the total porosity of light oil reservoirs according to claim 1, characterized in that, The step of measuring the total porosity of rock cores in a ground environment specifically includes: using full-diameter core nuclear magnetic resonance (NMR) technology to measure the total porosity of rock cores in a ground environment. .

3. The method for correcting the total porosity of light oil reservoirs according to claim 1, characterized in that, The relationship between the volume factor Bob and the compressibility factor Co of crude oil at the bubble point pressure is as follows: Where Co is the formation oil compressibility coefficient; Bo is the original formation oil volume coefficient; Bob is the oil volume coefficient at bubble point pressure; P is the original formation pressure; Pb is the bubble point pressure, and P > Pb.

4. The method for correcting the total porosity of light oil reservoirs according to claim 1, characterized in that, The specific calculation formula for calculating the gas overflow porosity based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions is as follows: in, Φo' represents the gas overflow porosity; This refers to the gas porosity of the core. The size is (1-1 / Bo) times the original oil-bearing porosity; Φgc is the gas-bearing porosity measured under ground conditions.

5. The method for correcting the total porosity of a light oil reservoir according to claim 1, characterized in that, The reduction in total porosity The calculation formula is as follows: in, The porosity is determined by the expansion of crude oil. This refers to the porosity at which gas escapes.

6. The method for correcting the total porosity of a light oil reservoir according to claim 1, characterized in that, The step of calculating the corrected total reservoir porosity based on the total core porosity and the reduction in total porosity is specifically calculated using the following formula: in, The corrected total porosity of the reservoir; This refers to the total porosity of the core. This represents the reduction in total porosity.

7. A system for correcting the total porosity of light oil reservoirs, characterized in that, A method for correcting the total porosity of a light oil reservoir according to any one of claims 1 to 6 includes: The porosity measurement module is used to measure the total porosity of core samples under surface conditions and to obtain the original formation pressure, bubble point pressure, gas-bearing porosity of the core sample, and gas-bearing porosity measured under surface conditions. The reduction calculation module is used to calculate the crude oil expansion overflow porosity based on the original formation pressure and bubble point pressure; and to calculate the gas overflow porosity based on the gas-bearing porosity of the core and the gas-bearing porosity measured under surface conditions, thereby obtaining the total porosity reduction. The correction module is used to calculate the corrected total porosity of the reservoir based on the total porosity of the core and the reduction in total porosity.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1-6.

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