Method, device, storage medium and electronic device for characterizing core dispersion velocity

Abstract

The present application belongs to the technical field of geological exploration and development, and provides a method and device for characterizing core dispersion velocity, a storage medium and an electronic device. The method can obtain a gas analysis data curve representing the relationship between each sampling time and the corresponding cumulative analysis gas volume by curve fitting of the metering data of the gas analysis test of each target position of the core sample, and then determine the initial dispersion velocity and the average dispersion velocity of the current target position based on the gas analysis data curve and the mass of the core sample. The initial dispersion velocity and the average dispersion velocity can truly reflect the shale reservoir condition, and the shale reservoir can be accurately evaluated.

Description

Technical Field

[0001] This invention belongs to the field of geological exploration and development technology, and in particular relates to a method, apparatus, storage medium and electronic equipment for characterizing the velocity of rock core dispersion. Background Technology

[0002] Shale gas refers to natural gas accumulations in organic-rich shale and its interlayered argillaceous siltstones. These are primarily self-generated and self-storing continuous gas reservoirs, existing in adsorbed and free states within extremely tight shale formations, and are considered unconventional natural gas. Shale reservoirs are characterized by low porosity and low permeability. In shale reservoir evaluation, identifying relatively high-permeability reservoirs is of great significance and is one of the important indicators for evaluating sweet spots.

[0003] Currently, shale permeability testing is mainly based on the pressure pulse decay method, which requires drilling small shale cores. However, during the drilling process, the properties of the core sample can easily limit the accuracy of the test results. In many cases, it may be impossible to drill out the cores, or the cores may deform or develop subtle cracks during the drilling process, ultimately affecting the objectivity of the test results. Therefore, a new method is needed to provide accurate and reliable evidence for shale reservoir evaluation. Summary of the Invention

[0004] This invention provides a method, apparatus, storage medium, and electronic device for characterizing core dispersion velocity, which can provide accurate and powerful evidence for shale reservoir evaluation.

[0005] In a first aspect, embodiments of the present invention provide a method for characterizing core dispersion velocity, comprising:

[0006] Obtain the metrological data of gas desorption testing at each target location in the core sample;

[0007] Based on the measurement data, curve fitting is performed to obtain a gas analysis data curve characterizing the relationship between each sampling time and the corresponding cumulative analysis gas volume;

[0008] Based on the gas analysis data curve and the mass of the core sample, the initial and average escape velocities at the current target location are determined.

[0009] In some embodiments, the measurement data in the above-described method for characterizing core escape velocity includes the cumulative desorbed gas volume at each sampling time.

[0010] In some embodiments, in the above method for characterizing core escape velocity, determining the initial escape velocity and average escape velocity at the current target location based on the gas desorption data curve and the mass of the core sample includes:

[0011] Determine the boundary point between the gas expansion stage and the gas dissipation stage on the gas analysis data curve, the analysis point at a first time interval from the boundary point, and the analysis completion point;

[0012] Based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample, the initial and average evaporation velocities at the current target location are determined.

[0013] In some embodiments, in the above method for characterizing core evaporation velocity, determining the initial evaporation velocity and average evaporation velocity at the current target location based on the boundary point, the resolution point, the resolution completion point, and the mass of the core sample includes:

[0014] The initial dissipation velocity at the current target position is determined based on a first calculation formula; the first calculation formula includes:

[0015] IDR=K AB / W

[0016] Where IDR represents the initial dissipation velocity, K AB W represents the slope of the straight line formed by the boundary point and the resolution point on the gas analysis data curve, and W represents the mass of the core sample.

[0017] The average dissipation velocity at the current target location is determined based on a second calculation formula; the second calculation formula includes:

[0018] ADR=K AC / W

[0019] Where ADR represents the average dissipation velocity, K AC This represents the slope of the straight line formed by the analysis point and the analysis completion point on the gas analysis data curve.

[0020] In some embodiments, the method for characterizing core escape velocity described above, prior to the step of acquiring the metrological data of gas desorption testing at each target location of the core sample, further includes:

[0021] Collect a full-diameter core sample from the target well, wherein the length and radius of the core sample are equal;

[0022] After drying the core sample, the mass of the core sample was obtained by weighing it.

[0023] The core sample is placed in a gas desorption container, filled with desorption gas, and then sealed to maintain the target environmental parameters inside the gas desorption device for a second duration.

[0024] Connect a gas analyzer to perform gas analysis, and generate measurement data for each target location of the core sample during the gas analysis process.

[0025] In some embodiments, the desorption gas in the above-described method for characterizing core escape velocity includes methane.

[0026] In some embodiments, in the above-described method for characterizing core escape velocity, the generation of metrological data for each target location of the core sample during gas desorption includes:

[0027] During the gas analysis process, measurement data at a sampling time for each target location of the core sample is generated at preset sampling intervals.

[0028] Secondly, embodiments of the present invention provide an apparatus for characterizing core dispersion velocity, comprising:

[0029] The acquisition module is used to acquire the metrological data of gas desorption testing at each target location of the core sample;

[0030] The fitting module is used to perform curve fitting based on the measurement data to obtain a gas analysis data curve that characterizes the relationship between each sampling time and the corresponding cumulative analysis gas volume.

[0031] The determination module is used to determine the initial and average escape velocities at the current target location based on the gas analysis data curve and the mass of the core sample.

[0032] Thirdly, embodiments of the present invention provide a storage medium storing a computer program, which, when executed by one or more processors, implements the method for characterizing core dispersion velocity as described in the first aspect.

[0033] Fourthly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the method for characterizing core escape velocity as described in the first aspect.

[0034] Compared with the prior art, one or more embodiments of the present invention can bring at least the following beneficial effects:

[0035] By performing curve fitting on the gas dissipation test data at each target location of the core sample, a gas dissipation data curve characterizing the relationship between each sampling time and the corresponding cumulative dissipated gas volume can be obtained. Based on the gas dissipation data curve and the mass of the core sample, the initial and average dissipation velocities at the current target location can be determined. The initial and average dissipation velocities accurately reflect the shale reservoir conditions, enabling a more objective and effective evaluation of shale reservoir parameters. This method is suitable for identifying high-permeability layers or sweet spots in shale oil and gas exploration and development evaluation. Attached Figure Description

[0036] 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.

[0037] Figure 1 This is a flowchart of a method for characterizing core dispersion velocity provided by an embodiment of the present invention;

[0038] Figure 2 This is a flowchart of another method for characterizing core dispersion velocity provided by an embodiment of the present invention;

[0039] Figure 3 This is a flowchart of another method for characterizing core dispersion velocity provided by an embodiment of the present invention;

[0040] Figure 4 This is a gas desorption data curve provided in an embodiment of the present invention;

[0041] Figure 5 This is a block diagram of a device for characterizing core dispersion velocity provided in an embodiment of the present invention. Detailed Implementation

[0042] 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. Therefore, the following detailed description of the embodiments of the present 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 present invention without inventive effort are within the scope of protection of the present invention.

[0043] In related technologies, rock cores are shaped into particles and placed in a temperature-controlled, sealed container. A certain pressure is applied, and the pressure change over time is recorded in real time to calculate the permeability of the shale matrix. This method eliminates the influence of fracture permeability on shale permeability testing, allowing for the measurement of the shale matrix permeability. However, while this method reduces the impact of fractures on permeability during testing, it is not fundamentally different from conventional permeability testing methods.

[0044] In related technologies, a gas collecting bottle is connected via a valve and a conduit for an external pressure gauge. Another port of the collecting bottle is connected to a velocity-measuring glass tube via a conduit and valve. The other end of the velocity-measuring glass tube is connected to an exhaust gas collecting bottle via a conduit and valve. The other port of the collecting bottle is open to the atmosphere. A weight and a protractor are suspended at the bottom of the velocity-measuring glass tube for tilt measurement, and a camera is placed parallel to the front of the measuring device for emission rate measurement. This scheme can analyze the relationship between formation dip angle and shale gas emission rate, as well as the variation law of shale gas emission rate under different physical properties. It compensates for the lack of laboratory measurement methods for shale gas emission rate. By replacing the rock formation with a liquid medium and slowly introducing methane gas into a velocity-measuring glass conduit filled with liquid medium, the emission rate of methane gas is indirectly measured by observing the migration rate of bubbles in the conduit. However, this method mainly determines the shale gas emission rate qualitatively through observation, rather than quantitatively. The obtained shale gas emission rate cannot reflect the actual emission situation of shale gas.

[0045] In related technologies, the pressure decay curve of the annular space between the core and the inner wall of the PVT container when methane gas flows radially along shale was obtained experimentally. Based on this, a corresponding mathematical model was established, and the semi-analytical relationship between pressure and time in the radial model was obtained. By fitting the experimental results, the concentration conductivity coefficient and porosity of the shale were obtained. Using the relationship between the concentration conductivity coefficient and permeability, the permeability value in the radial direction of the shale was obtained. Using this method, the permeability and porosity of two core samples were measured under three different initial pressures in the annular space. The permeability test results were compared with those of the traditional Dicker and Smits pressure decay methods, and the porosity test results were compared using a conventional porosity meter. Compared with the traditional pressure decay method, this method has the advantages of simpler equipment and operation, and can simultaneously obtain the radial permeability and porosity of shale. The main innovation of this method is obtaining the radial permeability and porosity of shale; however, it still requires drilling small cylinders and is easily affected by the properties of the sample.

[0046] Currently, shale permeability testing is mainly based on the pressure pulse decay method, which requires drilling small shale cores. During the drilling process, the properties of the core sample can easily limit the accuracy of the core sample, and in many cases, the core cannot be drilled at all. In addition, the core may deform or develop subtle cracks during the drilling process, which ultimately affects the objectivity of the test results. Therefore, a more objective and effective method for evaluating shale reservoir parameters and characterizing them is needed to accurately reflect the reservoir conditions of shale.

[0047] The technical solution of the present invention will be described in detail below with reference to several embodiments.

[0048] Example 1

[0049] Figure 1A flowchart of a method for characterizing core evaporation velocity is shown, as follows: Figure 1 As shown, this embodiment provides a method for characterizing core dispersion velocity, including steps S110 to S130:

[0050] Step S110: Obtain the measurement data of gas desorption test at each target location of the core sample.

[0051] In some implementations, the measurement data includes the cumulative desorbed gas volume at each sampling time.

[0052] In some cases, the measurement data may also include the analytical gas volume for each sampling time and the time range preceding the sampling time.

[0053] In practical applications, the measurement data can be presented in tabular form, including: sampling date, sampling time, the amount of gas removed during each sampling time and the time range preceding it, and the cumulative amount of gas removed during each sampling time. The target location can be any sampling location on the core sample.

[0054] Step S120: Perform curve fitting based on the measurement data to obtain a gas analysis data curve that characterizes the relationship between each sampling time and the corresponding cumulative analysis gas volume.

[0055] In practical applications, the horizontal axis of the gas desorption data curve can be time, and the vertical axis can be the cumulative desorption gas volume (ml). By using the measurement data, a curve reflecting the gas desorption situation at a certain target location (sample point) of the current core sample can be fitted. Based on this curve, information such as the gas expansion stage, the gas dissipation stage, and the point where desorption is completed can be determined.

[0056] Step S130: Based on the gas desorption data curve and the mass of the core sample, determine the initial and average escape velocity at the current target location.

[0057] In this embodiment, by curve fitting the gas analysis test data of each target location of the core sample, a gas analysis data curve characterizing the relationship between each sampling time and the corresponding cumulative gas analysis volume can be obtained. Then, based on the gas analysis data curve and the mass of the core sample, the initial escape velocity and average escape velocity of the current target location can be determined. The initial escape velocity and average escape velocity truly reflect the shale reservoir condition, enabling accurate evaluation of the shale reservoir. The reservoir where the target location has a higher initial escape velocity and average escape velocity is a relatively ideal sweet spot layer. For example, an initial escape velocity greater than 600 and an average escape velocity greater than 200 are relatively ideal sweet spots or high-permeability layers.

[0058] Figure 2A flowchart of another method for characterizing core evaporation velocity is shown, such as Figure 2 As shown, in some embodiments, step S130, based on the gas desorption data curve and the mass of the core sample, determines the initial and average escape velocities at the current target location, including:

[0059] Step S210: Determine the boundary point between the gas expansion stage and the gas dissipation stage on the gas analysis data curve, the analysis point with a first time interval from the boundary point, and the analysis completion point.

[0060] Specifically, based on the gas analysis data curve, the gas expansion stage and the gas dissipation stage can be determined, and then the boundary point A between the gas expansion stage and the gas dissipation stage can be determined. Based on this boundary point, analysis points B with a first time interval are taken along the gas analysis data curve. The period between this analysis point and the boundary point can be regarded as the initial gas dissipation stage, and the period after this analysis point can be regarded as the normal gas dissipation stage, until the analysis is completed at point C.

[0061] In practical applications, the first duration can be, but is not limited to, 1 hour.

[0062] Step S220: Based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample, determine the initial and average escaping velocities at the current target location.

[0063] In some implementations, step S220, based on the aforementioned boundary point, the aforementioned analysis point and analysis completion point, and the mass of the core sample, determines the initial and average evaporation velocities at the current target location, including:

[0064] The initial dissipation velocity at the current target position is determined based on a first calculation formula; the first calculation formula includes:

[0065] IDR=K AB / W

[0066] Where IDR represents the initial dissipation velocity, K AB The slope of the straight line formed by the above-mentioned boundary point and the above-mentioned resolution point on the gas desorption data curve is represented by W, which represents the mass of the core sample.

[0067] The average dissipation velocity at the current target location is determined based on the second calculation formula; the second calculation formula includes:

[0068] ADR=K AC / W

[0069] Where ADR represents the average dissipation velocity, K AC This represents the slope of the straight line formed by the aforementioned analysis point and the aforementioned analysis completion point on the gas analysis data curve.

[0070] It should be understood that the initial escape velocity characterizes the amount of gas exfoliated per unit mass of rock sample per unit time during the initial gas escape stage, reflecting the rate of gas exfoliation per unit mass of rock sample per unit time during the initial gas escape stage. The average escape velocity characterizes the amount of gas exfoliated per unit mass of rock sample per unit time during the entire gas escape stage, reflecting the rate of gas exfoliation per unit mass of rock sample per unit time during the entire gas escape stage. The unit time can be, but is not limited to, one hour.

[0071] In practical applications, the mass W of the core sample can be obtained by weighing, and the unit can be kg.

[0072] Figure 3 A flowchart of another method for characterizing core evaporation velocity is shown, such as Figure 3 As shown, in some embodiments, before step S110, which involves acquiring the metrological data of gas desorption testing at each target location of the core sample, the method may further include:

[0073] Step S310: Collect a full-diameter core sample from the target well, ensuring that the length and radius of the core sample are equal.

[0074] In practical applications, after identifying a fresh (shale) target well, drilling a full-diameter core sample from that well can accurately reflect the reservoir conditions of that well.

[0075] Step S320: After drying the core sample, weigh it to obtain the mass W of the core sample.

[0076] Step S330: Place the core sample into the gas desorption container, fill it with desorption gas, and seal it to keep the gas desorption device under the target environmental parameters for the second duration.

[0077] In some implementations, the desorption gas may include, but is not limited to, methane.

[0078] In practical applications, the gas desorption container can be a sealable container such as a desorption tank. The target environmental parameters include, but are not limited to, room temperature (e.g., 22 degrees Celsius) and a pressure of 5 MPa inside the desorption tank. The second duration can be, but is not limited to, 2-3 hours. After placing the core sample into the gas desorption container, the container is filled with desorption gas and then sealed. This keeps the gas desorption device under the target environmental parameters for the second duration, allowing the environment inside the gas desorption container to reach equilibrium.

[0079] Step S340: Connect the gas analysis instrument to perform gas analysis, and generate measurement data for each target location of the core sample during the gas analysis process.

[0080] In practical applications, the gas analysis instrument can be, but is not limited to, the rock gas content measuring device disclosed in the patent authorization document with patent number 201310176273.7. It should be understood that other analysis instruments can also be used in practical applications to perform gas analysis of shale core samples. This embodiment does not impose any limitations.

[0081] In some implementations, step S340 generates metrological data for each target location of the core sample during gas desorption, including:

[0082] During gas desorption, measurement data for each target location in the core sample is generated at preset sampling intervals. Correspondingly, a gas desorption data curve is fitted for each target location, and the initial and average escape velocities are calculated. The preset sampling interval can be, but is not limited to, 30 seconds.

[0083] In this embodiment, by curve fitting the gas desorption test data of each target location of the full-diameter core sample, a gas desorption data curve characterizing the relationship between each sampling time and the corresponding cumulative desorption gas volume can be obtained. Based on the gas desorption data curve and the mass of the core sample, the initial and average evaporation velocities at the current target location are determined, providing a true and effective basis for accurate evaluation of shale reservoirs. This method achieves a rapid, effective, and comprehensive characterization of the evaporation velocity of mudstone and shale. Moreover, the method is inexpensive and simple to operate, and the calculated evaporation velocity of mudstone and shale will be an important evaluation parameter in the exploration and development of shale oil and shale gas.

[0084] Example 2

[0085] Example of a method for characterizing core escape velocity provided in Example 1.

[0086] Taking well X in a certain area as the target well, the escape velocity was characterized:

[0087] Well X is a shale gas coring well. A full-diameter shale core sample was collected, measuring 11 cm in diameter and 5.5 cm in length. After drying, it was weighed to obtain a weight of 2.877 kg and placed in a desorption container with an inner diameter of 12 cm and a height of 6 cm, large enough to hold the core sample. Methane gas was injected, and the container was sealed, maintaining a pressure of 5 MPa and a temperature of 20 degrees Celsius. Then, it was connected to an analytical instrument for analysis. The analytical data for a specific target location are shown in Table 1.

[0088] Table 1. Changes in desorbed gas volume over time

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] Based on the measurement data shown in Table 1, a fitting curve was obtained as follows: Figure 4 The gas analysis data curves shown indicate that point A is the boundary between the gas expansion stage and the normal shale dissipation stage, representing a relatively clear inflection point. The interval from point A to analysis point B is 1 hour, and point C is the analysis completion point. The slope of line AB represents the initial dissipation velocity (IDR) of the shale core sample, and the slope of line AC represents the average dissipation velocity (ADR) of the shale core sample. Initial dissipation velocity (IDR) and average dissipation velocity (ADR) are important parameters for shale gas reservoir evaluation. Experimentally determining the initial dissipation velocity (IDR) and average dissipation velocity (ADR) at different (target) locations within a complete (full diameter) core column can provide important reference for determining shale gas sweet spots / high-permeability layers. In this example, the slope of line AB is calculated to be 2708.220981, and the slope of line AC is 1102.286448. Combining this with the mass of the core sample, the following can be calculated:

[0103] The initial escape velocity at the current target location of the core sample:

[0104] IDR=K AB / W = 941.3350648 (ml / kg·h)

[0105] The average escape velocity at the current target location of this core sample:

[0106] IDR=K AC / W = 383.1374516 (ml / kg·h)

[0107] The initial escape velocity (IDR) and average escape velocity (ADR) of the current target location of this core sample are relatively high, and the reservoir corresponding to the current target location is a relatively ideal sweet spot layer location.

[0108] Example 3

[0109] Figure 5 A block diagram of a device for characterizing core dispersion velocity is shown, such as... Figure 5 As shown, this embodiment provides an apparatus for characterizing core dispersion velocity, comprising:

[0110] The acquisition module 510 is used to acquire the measurement data of gas desorption test at each target location of the core sample;

[0111] The fitting module 520 is used to perform curve fitting based on the measurement data to obtain a gas analysis data curve that characterizes the relationship between each sampling time and the corresponding cumulative analysis gas volume.

[0112] The determination module 530 is used to determine the initial and average escape velocities at the current target location based on the gas analysis data curve and the mass of the core sample.

[0113] The acquisition module 510 described above can be used to execute step S110 in Embodiment 1, the fitting module 520 can be used to execute step S120 in Embodiment 1, and the determination module 530 can be used to execute step S130 in Embodiment 1. For specific steps, please refer to Embodiment 1, which will not be repeated in this embodiment.

[0114] Those skilled in the art will understand that the above-described modules or steps can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by the computing device, or fabricating them separately as individual integrated circuit modules, or fabricating multiple modules or steps into a single integrated circuit module. This invention is not limited to any specific hardware and software combination.

[0115] Example 4

[0116] This embodiment provides a storage medium storing a computer program that, when executed by one or more processors, implements the method for characterizing core escape velocity as described in Embodiment 1.

[0117] In this embodiment, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0118] When executed by one or more processors, the computer program implements methods for characterizing core escape velocities, including:

[0119] Step S110: Obtain the measurement data of gas desorption test at each target location of the core sample.

[0120] Step S120: Perform curve fitting based on the measurement data to obtain a gas analysis data curve that characterizes the relationship between each sampling time and the corresponding cumulative analysis gas volume.

[0121] Step S130: Based on the gas desorption data curve and the mass of the core sample, determine the initial and average escape velocity at the current target location.

[0122] In some implementations, step S130, based on the gas desorption data curve and the mass of the core sample, determines the initial and average escape velocities at the current target location, including:

[0123] Step S210: Determine the boundary point between the gas expansion stage and the gas dissipation stage on the gas analysis data curve, the analysis point with a first time interval from the boundary point, and the analysis completion point.

[0124] Step S220: Based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample, determine the initial and average escaping velocities at the current target location.

[0125] In some implementations, step S220, based on the aforementioned boundary point, the aforementioned analysis point and analysis completion point, and the mass of the core sample, determines the initial and average evaporation velocities at the current target location, including:

[0126] The initial dissipation velocity at the current target position is determined based on a first calculation formula; the first calculation formula includes:

[0127] IDR=K AB / W

[0128] Where IDR represents the initial dissipation velocity, K AB The slope of the straight line formed by the above-mentioned boundary point and the above-mentioned resolution point on the gas desorption data curve is represented by W, which represents the mass of the core sample.

[0129] The average dissipation velocity at the current target location is determined based on the second calculation formula; the second calculation formula includes:

[0130] ADR=K AC / W

[0131] Where ADR represents the average dissipation velocity, K AC This represents the slope of the straight line formed by the aforementioned analysis point and the aforementioned analysis completion point on the gas analysis data curve.

[0132] Example 5

[0133] This embodiment provides an electronic device, including a memory and a processor. The memory stores a computer program, which, when executed by the processor, implements the method for characterizing core dispersion velocity as described in Embodiment 1.

[0134] In this embodiment, the processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic components, and is used to execute the methods in the above embodiments. The methods implemented when the computer program running on the processor is executed can be referred to the specific embodiments of the methods provided in the foregoing embodiments of this invention, and will not be repeated here.

[0135] When executed by a processor, the computer program implements methods for characterizing core dispersion velocities, including:

[0136] Step S110: Obtain the measurement data of gas desorption test at each target location of the core sample.

[0137] Step S120: Perform curve fitting based on the measurement data to obtain a gas analysis data curve that characterizes the relationship between each sampling time and the corresponding cumulative analysis gas volume.

[0138] Step S130: Based on the gas desorption data curve and the mass of the core sample, determine the initial and average escape velocity at the current target location.

[0139] In some implementations, step S130, based on the gas desorption data curve and the mass of the core sample, determines the initial and average escape velocities at the current target location, including:

[0140] Step S210: Determine the boundary point between the gas expansion stage and the gas dissipation stage on the gas analysis data curve, the analysis point with a first time interval from the boundary point, and the analysis completion point.

[0141] Step S220: Based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample, determine the initial and average escaping velocities at the current target location.

[0142] In some implementations, step S220, based on the aforementioned boundary point, the aforementioned analysis point and analysis completion point, and the mass of the core sample, determines the initial and average evaporation velocities at the current target location, including:

[0143] The initial dissipation velocity at the current target position is determined based on a first calculation formula; the first calculation formula includes:

[0144] IDR=K AB / W

[0145] Where IDR represents the initial dissipation velocity, K AB The slope of the straight line formed by the above-mentioned boundary point and the above-mentioned resolution point on the gas desorption data curve is represented by W, which represents the mass of the core sample.

[0146] The average dissipation velocity at the current target location is determined based on the second calculation formula; the second calculation formula includes:

[0147] ADR=K AC / W

[0148] Where ADR represents the average dissipation velocity, K AC This represents the slope of the straight line formed by the aforementioned analysis point and the aforementioned analysis completion point on the gas analysis data curve.

[0149] In the several embodiments provided in this invention, it should be understood that the disclosed systems and methods can also be implemented in other ways. The system and method embodiments described above are merely illustrative.

[0150] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0151] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for characterizing core dispersion velocity, characterized in that, include: Obtain the metrological data of gas desorption testing at each target location in the core sample; Based on the measurement data, curve fitting is performed to obtain a gas analysis data curve characterizing the relationship between each sampling time and the corresponding cumulative analysis gas volume; Based on the gas analysis data curve and the mass of the core sample, the initial and average dissipation velocities at the current target location are determined, including: determining the boundary point between the gas expansion stage and the gas dissipation stage on the gas analysis data curve, the analysis point at a first time interval from the boundary point, and the analysis completion point; and determining the initial and average dissipation velocities at the current target location based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample. The determination of the initial and average evaporation velocities at the current target location based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample includes: The initial dissipation velocity at the current target position is determined based on a first calculation formula; the first calculation formula includes: IDR=K AB / W Where IDR represents the initial dissipation velocity, K AB W represents the slope of the straight line formed by the boundary point and the resolution point on the gas analysis data curve, and W represents the mass of the core sample. The average dissipation velocity at the current target location is determined based on a second calculation formula; the second calculation formula includes: ADR=K AC / IN Where ADR represents the average dissipation velocity, K AC This represents the slope of the straight line formed by the analysis point and the analysis completion point on the gas analysis data curve.

2. The method for characterizing core dispersion velocity according to claim 1, characterized in that, The measurement data includes the cumulative desorbed gas volume at each sampling time.

3. The method for characterizing core dispersion velocity according to claim 1, characterized in that, Before the step of obtaining the metrological data of gas desorption testing at each target location of the core sample, the method further includes: Collect a full-diameter core sample from the target well, wherein the length and radius of the core sample are equal; After drying the core sample, the mass of the core sample was obtained by weighing it. The core sample was placed in a gas desorption container, filled with desorption gas, and then sealed to maintain the target environmental parameters inside the gas desorption container for a second duration. Connect a gas analyzer to perform gas analysis, and generate measurement data for each target location of the core sample during the gas analysis process.

4. The method for characterizing core dispersion velocity according to claim 3, characterized in that, The desorbed gas includes methane.

5. The method for characterizing core dispersion velocity according to claim 3, characterized in that, The generation of measurement data for each target location of the core sample during gas desorption includes: During the gas analysis process, measurement data at a sampling time for each target location of the core sample is generated at preset sampling intervals.

6. A device for characterizing the escape velocity of a rock core, characterized in that, include: The acquisition module is used to acquire the metrological data of gas desorption testing at each target location of the core sample; The fitting module is used to perform curve fitting based on the measurement data to obtain a gas analysis data curve that characterizes the relationship between each sampling time and the corresponding cumulative analysis gas volume. The determination module is used to determine the initial and average dissipation velocities at the current target location based on the gas analysis data curve and the mass of the core sample. This includes: determining the boundary point between the gas expansion stage and the gas dissipation stage on the gas analysis data curve, the analysis point spaced a first time interval from the boundary point, and the analysis completion point; and determining the initial and average dissipation velocities at the current target location based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample. The determination of the initial and average evaporation velocities at the current target location based on the boundary point, the analysis point, the analysis completion point, and the mass of the core sample includes: The initial dissipation velocity at the current target position is determined based on a first calculation formula; the first calculation formula includes: IDR=K AB / W Where IDR represents the initial dissipation velocity, K AB W represents the slope of the straight line formed by the boundary point and the resolution point on the gas analysis data curve, and W represents the mass of the core sample. The average dissipation velocity at the current target location is determined based on a second calculation formula; the second calculation formula includes: ADR=K AC / IN Where ADR represents the average dissipation velocity, K AC This represents the slope of the straight line formed by the analysis point and the analysis completion point on the gas analysis data curve.

7. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by one or more processors, implements the method for characterizing core escape velocity as described in claim 1 or 2.

8. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the method for characterizing core escape velocity as described in claim 1 or 2.

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