Helium-rich natural gas reservoir efficiency evaluation method, device, system and storage medium

Abstract

The present invention provides a method, device, system and storage medium for evaluating the reservoir formation efficiency of helium-rich natural gas. The method includes: obtaining geological data of an underground reservoir rock sample to be evaluated; calculating the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuuming according to the dry weight nuclear magnetic resonance spectrum signal, the linear fitting slope of different volumes of target fluid and nuclear magnetic signal quantity, and the nuclear magnetic resonance spectrum signal after vacuuming and saturating the target fluid; determining the gas drive efficiency and reservoir formation pressure of the underground reservoir rock sample to be evaluated under different gas drive pressures according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuuming; evaluating the reservoir formation efficiency of the underground reservoir rock sample to be evaluated according to the reservoir formation pressure and the volume of the target fluid of the underground reservoir rock sample to be evaluated. The present invention improves the accuracy of the evaluation results of the reservoir formation efficiency of helium-rich natural gas by simulating the real geological historical conditions through analyzing the changes under different pressures.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas exploration technology, and in particular to a helium-rich natural gas reservoir efficiency evaluation method, device, system and storage medium. Background Art

[0002] Helium (He), with its unique physical and chemical properties, including high thermal conductivity and strong chemical inertness, is widely used in the defense industry and high-tech fields, making it a very important strategic resource. Helium generally exists as a gas molecule, is lightweight and highly diffusible, making geological theory and exploration and development technology research on He as a natural gas resource increasingly important.

[0003] However, the microscopic mechanisms of helium's migration and accumulation after generation differ significantly from those of natural gas. Furthermore, the helium discovered so far often combines with other gases, such as methane, to form helium-rich natural gas, ultimately accumulating in reservoirs. There are no geological examples of pure helium accumulation. Before the formation of helium-rich natural gas reservoirs, various fluids, such as magmatic hydrothermal fluids, formation water, and other gases, may exist within the rock reservoir. As helium-rich natural gas is generated and migrates into the rock reservoir, it displaces the pre-existing fluids, ultimately forming helium-rich natural gas reservoirs. Existing research primarily examines helium-rich natural gas from the perspectives of geological structure, lithologic distribution, genetic sources, and resource assessment. Microscopic studies of the accumulation mechanisms of helium-rich natural gas, particularly its accumulation efficiency (the proportion of helium in a reservoir), remain exploratory and lack qualitative and quantitative characterization parameters. Summary of the Invention

[0004] The embodiments of the present invention provide a method, device, system and storage medium for evaluating the reservoir formation efficiency of helium-rich natural gas, so as to solve the problem of lack of effective evaluation of the reservoir formation efficiency of natural gas at present.

[0005] In a first aspect, an embodiment of the present invention provides a method for evaluating the efficiency of helium-rich natural gas accumulation, comprising:

[0006] Obtaining geological data of the underground reservoir rock sample to be evaluated; wherein the geological data includes dry weight nuclear magnetic resonance spectrum signal, slope of linear fitting between different volumes of target fluid and nuclear magnetic resonance signal, and nuclear magnetic resonance spectrum signal after vacuum saturation of target fluid;

[0007] Calculate the volume of the target fluid after the rock sample in the underground reservoir to be evaluated is saturated with the target fluid by vacuuming, based on the dry weight nuclear magnetic resonance spectrum signal, the slope of the linear fitting between the target fluid and the nuclear magnetic signal at different volumes, and the nuclear magnetic resonance spectrum signal after vacuuming and saturating the target fluid;

[0008] Determine the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid;

[0009] Determine the reservoir formation pressure based on the gas drive efficiency at different gas drive pressures;

[0010] The reservoir forming efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the reservoir forming pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid.

[0011] In one possible implementation, the reservoir formation pressure is determined based on the gas drive efficiency at different gas drive pressures, including:

[0012] Draw a gas drive pressure-gas drive efficiency diagram based on the gas drive efficiency under different gas drive pressures and their corresponding gas drive pressures;

[0013] In the gas drive pressure-gas drive efficiency diagram, when the slope of the curve is no greater than a first preset threshold, the corresponding gas drive pressure is taken as the reservoir forming pressure.

[0014] In a possible implementation, the geological data also includes the mass of the target fluid after vacuum saturation and the mass of the underground reservoir rock samples to be evaluated at different gas drive pressures;

[0015] The gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures is determined based on the volume of the target fluid after the target fluid is saturated by vacuum in the underground reservoir rock sample to be evaluated, including:

[0016] The gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the one-dimensional nuclear magnetic resonance spectrum is calculated based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid, the mass of the underground reservoir rock sample to be evaluated after being vacuum-saturated with the target fluid, the mass of the underground reservoir rock sample to be evaluated at different gas drive pressures, and the first calculation formula.

[0017] In one possible implementation, the reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the reservoir formation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum, including:

[0018] Determine the volume of helium in the underground reservoir rock sample to be evaluated at the reservoir pressure in the one-dimensional nuclear magnetic resonance spectrum based on the reservoir formation pressure of the underground reservoir rock sample to be evaluated;

[0019] Calculating the accumulation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum according to the volume of helium in the underground reservoir rock sample to be evaluated, the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum, and a second calculation formula;

[0020] The reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum.

[0021] In a possible implementation, the geological data further includes different gas drive pressures and linear fitting slopes of target hydrocarbon gas nuclear magnetic signal quantities per unit pressure and per unit volume at different gas drive pressures;

[0022] The first calculation formula is:

[0023]

[0024] in, is the gas flooding efficiency of the underground reservoir rock sample to be evaluated at different gas flooding pressures in the one-dimensional nuclear magnetic resonance spectrum; is the mass of the target fluid after vacuum saturation; is the mass of underground reservoir rock samples to be evaluated at different gas flooding pressures; is the density of the target fluid; The volume of the target fluid after the rock sample of the underground reservoir to be evaluated is vacuumed and saturated with the target fluid;

[0025] The volume of helium is determined by the following formula:

[0026]

[0027]

[0028]

[0029] in, is the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum; is the volume of target hydrocarbon gas in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum; is the volume of helium in the rock sample of the underground reservoir to be evaluated at the reservoir formation pressure; The slope of the linear fitting of different volumes of target fluid and NMR signal; is the reservoir formation pressure in one-dimensional nuclear magnetic resonance spectroscopy; The linear fitting slopes of the target hydrocarbon gas NMR signal per unit pressure and per unit volume at different gas drive pressures; is the signal amount of NMR spectrum under different gas driving pressures;

[0030] The second calculation formula is:

[0031]

[0032] in, is the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum.

[0033] In a possible implementation, the geological data also includes nuclear magnetic signal quantities of the target fluid at different gas drive pressures;

[0034] The gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures is determined based on the volume of the target fluid after the target fluid is saturated by vacuum in the underground reservoir rock sample to be evaluated, including:

[0035] The gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the two-dimensional nuclear magnetic resonance spectrum is calculated based on the volume of the target fluid after the target fluid is saturated with the target fluid by vacuum, the nuclear magnetic signal amount of the target fluid at different gas drive pressures, the linear fitting slope of the target fluid at different volumes and the nuclear magnetic signal amount, and the third calculation formula;

[0036] The reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the reservoir formation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum, including:

[0037] Determine the methane volume of the underground reservoir rock sample to be evaluated at the accumulation pressure in the two-dimensional nuclear magnetic resonance spectrum according to the accumulation pressure of the underground reservoir rock sample to be evaluated;

[0038] Based on the NMR signal of the target fluid at different gas drive pressures and the slope of the linear fitting between the target fluid volume and the NMR signal, the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional NMR spectrum is calculated;

[0039] Calculate the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum, the volume of the target hydrocarbon gas in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum, the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum, and a fourth calculation formula;

[0040] The reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum.

[0041] In a possible implementation, the third calculation formula is:

[0042]

[0043] in, is the gas flooding efficiency of the underground reservoir rock sample to be evaluated at different gas flooding pressures in the two-dimensional nuclear magnetic resonance spectrum; is the NMR signal of the target fluid under different gas drive pressures;

[0044] The target hydrocarbon gas volume is determined by the following formula:

[0045]

[0046] in, is the volume of target hydrocarbon gas in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum; is the signal amount of target hydrocarbon gas at the reservoir pressure in the two-dimensional nuclear magnetic resonance spectrum; is the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum;

[0047] The fourth calculation formula is:

[0048]

[0049] in, is the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum; is the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum.

[0050] In a second aspect, an embodiment of the present invention provides a display device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0051] In a third aspect, an embodiment of the present invention provides a helium-rich natural gas reservoir efficiency evaluation system, comprising a vacuum saturation device, a simulation test device, a gas supply device, a recovery device, and the display device described in the second aspect.

[0052] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the method described in the first aspect or any possible implementation of the first aspect.

[0053] Embodiments of the present invention provide a method, device, system, and storage medium for evaluating the reservoir formation efficiency of helium-rich natural gas. Compared to traditional methods, the embodiments of the present invention analyze changes under different pressures and simulate realistic geological historical conditions to obtain the reservoir pressure and reservoir formation rate of helium-rich natural gas with a certain degree of accuracy. Furthermore, the embodiments of the present invention employ a comprehensive and systematic approach to regress the direct influence of external fluids on different types of rock reservoirs, unaffected by external representations or human factors. The evaluation results are more scientific and objective, and the evaluation of helium reservoir formation efficiency in rock samples of underground reservoirs to be evaluated fills a gap in this field, providing a theoretical basis for detecting helium reservoir formation efficiency and improving the accuracy of evaluation of helium-rich natural gas reservoir formation efficiency. Furthermore, the provided method is not limited by different rock types and is generally applicable to all types of rock reservoirs currently in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0055] Figure 1 Schematic diagram of the structure of the helium-rich natural gas reservoir efficiency evaluation system provided by an embodiment of the present invention;

[0056] Figure 2 This is a flow chart for implementing a method for evaluating the efficiency of helium-rich natural gas accumulation provided by an embodiment of the present invention;

[0057] FIG3 (a)-(b) are fitted calibration spectra of the helium-rich natural gas accumulation efficiency evaluation method provided by an embodiment of the present invention;

[0058] Figure 4 It is a one-dimensional spectrum of water displacement nuclear magnetic resonance signals of the helium-rich natural gas reservoir efficiency evaluation method provided by an embodiment of the present invention;

[0059] 5(a)-(i) are two-dimensional spectra of water displacement nuclear magnetic resonance signals of the helium-rich natural gas reservoir efficiency evaluation method provided by an embodiment of the present invention;

[0060] Figure 6 1. A gas drive pressure-gas drive efficiency diagram of a helium-rich natural gas reservoir efficiency evaluation method provided in an embodiment of the present invention;

[0061] Figure 7 is a schematic diagram of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0063] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0064] In this embodiment, for the sake of detailed description and ease of explanation, in the following related embodiments, water is used to refer to the target fluid and methane is used to refer to the target alkane gas; however, those skilled in the art should understand that the target fluid may include underground cold water, underground hot water, petroleum, magma and mineral fluid, as well as magma vaporized substances and alienated substances produced under natural conditions, etc.; the target alkane gas may include methane, ethane, butane, cycloalkanes, etc., and the use of water to refer to the target fluid and methane to refer to the target alkane gas is only to provide a feasible embodiment and does not constitute any limitation to this solution.

[0065] Figure 1 FIG. 1 is a schematic diagram of a helium-rich natural gas reservoir efficiency evaluation system according to an embodiment of the present invention. Figure 1 As shown:

[0066] In this embodiment, before evaluating the helium-rich natural gas accumulation efficiency, it is necessary to pre-process the underground reservoir rock sample to be evaluated to obtain the geological data of the underground reservoir rock sample to be evaluated. Figure 1 The vacuum saturation device 2, simulation test device 3, gas supply device 4 and recovery device 5 in the system are used to pre-process the underground reservoir rock samples to be evaluated, obtain geological data, and then Figure 1 The display device 1 in the embodiment is used to analyze geological data to evaluate the efficiency of helium-rich natural gas accumulation.

[0067] In a specific embodiment, the system may further include a base 6, which is in the shape of a rectangular parallelepiped, so that the overall bottom weight of the system is large and the ground contact area is large, which can ensure the stability of the system instrument during the experiment. The base 6 connects and places the display device 1, the vacuum saturation device 2, the simulation test device 3, the air supply device 4 and the recovery device 5.

[0068] The vacuum saturation device 2 consists of a vacuum pump 21, a first valve 22, a first core chamber 23, a first pressure sensor 24, a second valve 25, a replaceable fluid tank 26 and a first pressure pump 27. It is used to vacuum saturate the core with water (or other fluid) according to the experimental purpose or formation pressure, simulate the saturated water (or other fluid) state of the core required by the experimental purpose or under actual formation conditions, and determine the linear fitting slope of different volumes of water and nuclear magnetic resonance signal quantity, and the nuclear magnetic resonance spectrum signal after vacuum saturation with water.

[0069] Simulation test apparatus 3 consists of a nuclear magnetic resonance (NMR) device 3(a) and an online weighing device 3(b). NMR device 3(a) comprises a second core chamber 31, a heating coil 32, a temperature sensor 33, a first magnet 34, a second magnet 35, a core holder 36, and a third pressure sensor 37. The NMR device controls the magnetic field within the test space containing the first and second magnets 34, 35, and the rock sample, ensuring a stable and uniform magnetic field environment for the sample and the accuracy of the NMR signal. Furthermore, the core holder 36 and heating coil 32 simulate the core sample's temperature and confining pressure according to the experimental objectives or formation conditions. Online weighing device 3(b) is connected to the second core chamber 31 via an electronic cable and is used to monitor changes in sample mass within the core chamber in real time.

[0070] The gas supply device 4 includes a replaceable gas tank 41, a second pressure pump 42, a third valve 43 and a second pressure sensor 44, which are used to supply different proportions of helium and methane (or other hydrocarbon gases) to the entire experimental equipment according to the experimental purpose or formation conditions. Different gas drive pressures are set by the second pressure pump 42, and the supplied gas is used to drive water (or other fluids) in the core in a fully saturated water (or other fluid) state.

[0071] The recovery device 5 includes a gas recovery tank 51, a liquid fluid recovery tank 52, a fourth valve 53 and a fifth valve 54, and is used to recover water (or other liquid fluids) and gas flowing out of the core chamber during the experimental test.

[0072] The display device 1 is a terminal device, which is connected to the vacuum saturation device 2, the simulation test device 3, the gas supply device 4 and the recovery device 5 through electronic cables. It can control the entire test process and display the nuclear magnetic resonance spectrum of the rock sample under different states, the sample mass change and the calculated signal amount. It can analyze the dynamic changes of helium-rich natural gas drive accumulation in the rock sample, calculate the "accumulation pressure" and "accumulation rate", and evaluate the helium-rich natural gas accumulation efficiency in the rock sample.

[0073] Specifically, the method provided by the embodiment of the present invention is briefly described in conjunction with the system provided by this embodiment:

[0074] (1) Sample processing

[0075] Obtain rock samples of the underground reservoir that need to be evaluated.

[0076] (2) Sample drying

[0077] The sample was placed in a drying oven for drying to remove moisture from the sample, the dry weight of the sample was measured, and the dry weight sample nuclear magnetic resonance spectrum signal was obtained by testing.

[0078] (3) Calibration of water (or other fluid) signals and methane (or other hydrocarbon gas) signals in rock samples

[0079] The relationship between different volumes of water (or other fluids) and the nuclear magnetic resonance signal is calculated and determined using standard water (or other fluid) samples. The relationship between different gas drive pressures and the nuclear magnetic resonance signal of methane (or other hydrocarbon gas) per unit pressure and unit volume at different gas drive pressures is determined using the change in nuclear magnetic resonance signal of standard methane (or other hydrocarbon gas) samples at different gas drive pressures.

[0080] (4) Vacuum the sample and saturate it with water (or other fluid)

[0081] The sample is placed in a vacuum saturation device 2. After evacuation, the pressure is set in the vacuum environment to saturate the sample with water (or other fluid). The mass of the sample saturated with water (or other fluid) is measured, and the nuclear magnetic resonance spectrum signal of the sample saturated with water (or other fluid) is tested.

[0082] (5) Mixed gas of helium and methane (or other hydrocarbon gases) to displace water (or other fluids) in the sample

[0083] Test the nuclear magnetic resonance signal spectrum of a mixed gas of helium and methane (or other hydrocarbon gases) (the mixing ratio is set according to the actual formation conditions or experimental purpose) displacing water (or other fluids) at different gas drive pressures, measure the nuclear magnetic resonance spectrum signal quantity and mass changes at different gas drive pressures, and draw the nuclear magnetic signal spectra at different gas drive pressures.

[0084] (6) Calculation of reservoir formation pressure and rate

[0085] According to the NMR signal quantities of the samples under different states obtained in steps (2), (3), (4) and (5), the gas drive efficiency corresponding to different gas drive pressures is calculated, and a gas drive pressure-gas drive efficiency point-line graph is drawn. The gas drive pressure corresponding to when the slope of the curve gradually approaches 0 is the "accumulation pressure", and the "accumulation rate" is calculated based on the NMR spectrum signal quantity, sample quality and other data under the "accumulation pressure".

[0086] (7) Accurately evaluate the accumulation efficiency of helium-rich natural gas reservoirs

[0087] Based on multiple experimental test data of different types of rock samples, the "accumulation rate" is divided into three ranges: excellent, good, and poor. Based on this, the efficiency of helium-rich natural gas accumulation in the cores obtained from the experimental tests is evaluated.

[0088] The method is described in detail below through the following embodiments:

[0089] Figure 2 This is a flow chart of the method for evaluating the efficiency of helium-rich natural gas accumulation provided by an embodiment of the present invention; Figure 1 and Figure 2 , the method provided by the embodiment of the present invention is described in detail. Specifically, the method includes:

[0090] Step 110: Acquire geological data of the underground reservoir rock sample to be evaluated; wherein the geological data includes dry weight nuclear magnetic resonance spectrum signal, linear fitting slope of different volumes of target fluid and nuclear magnetic signal quantity, and nuclear magnetic resonance spectrum signal after vacuum saturation of target fluid.

[0091] In this embodiment, in order to obtain geological data of the underground reservoir rock sample to be evaluated, a target layer rock reservoir sample to be evaluated can be collected, and a complete large rock sample can be selected. A cylindrical sample with a diameter of approximately 2.5 cm and a length of 5 cm can be obtained using a water cutting or wire cutting method. The following is a detailed description of obtaining geological data of the underground reservoir rock sample to be evaluated. It should be noted that the fluid selected in the following embodiment is not limited to water, but can also include other fluids. For ease of explanation, water is selected as an example. The gas selected is not limited to methane, but can also be other hydrocarbon gases. For ease of explanation, methane is selected as an example. In actual use, other fluids or other alkane gases can also be selected to replace the water or methane in this embodiment.

[0092] Specifically, two samples are taken, one of which is placed in a drying oven for drying. The drying temperature can be set to 110°C and the drying time is not less than 24 hours in order to remove moisture from the sample. The sample is then placed in the core chamber 2, and the display device 1 is used to control the simulation test device 3 to set the test core sample conditions to be HMPa, a temperature of 25°C, and a dry weight of the test sample. m 干 , based on the sample dry weight m 干 The dry weight NMR spectrum signal was obtained by testing S 干 ; Among them, H is a parameter that can be set as needed, such as 29, 29.5, 30, etc., and is not limited here.

[0093] The sample is placed in the first core chamber 23 of the vacuum saturation device 2, the first valve 22 is opened, and after vacuuming for 1 hour, the first valve 22 is closed. The saturated water pressure of the first pressure pump 27 is set to 30 MPa through the display device 1, and the valve 2 is opened to saturate the sample with water in a vacuum environment for 24 hours. The sample is then taken out and placed in the second core chamber 31, and all valves are kept closed. The simulation test device 3 is controlled by the display device 1 to set the test core sample conditions to a confining pressure of 30 MPa and a temperature of 25°C, and the mass of the sample after vacuuming and saturating with water is measured. m 饱 , according to the mass of the sample after vacuum saturation with water m 饱 , test the nuclear magnetic resonance spectrum signal of vacuum saturated water sample S 饱 .

[0094] The second sample was calibrated for water and methane signals. Specifically, the water signal calibration process is described below in conjunction with the fitted calibration spectrum of water in Figure 3(a):

[0095] In FIG3 (a), the abscissa is the water volume, and the ordinate is the nuclear magnetic resonance spectrum signal corresponding to each water volume. Specifically, water samples of different volumes, such as 0.05 ml, 0.6 ml, 1 ml, 2 ml, and 3 ml, are selected (the water sample can be pure water or a water sample can be prepared according to the actual formation water conditions, and other fluids are the same). The display device 1 controls the simulation test device 3 to set the test core sample conditions to a confining pressure of 30 MPa and a temperature of 25°C, and the sample is placed in the second core chamber 31. The linear relationship between the nuclear magnetic signal and the water volume under these conditions is obtained by testing. The linear fitting degree must reach more than 99% to obtain the linear relationship between the nuclear magnetic signal and the water quality under these parameters. When the linear fitting degree reaches more than 99%, the following fitting curve formula is obtained:

[0096]

[0097] in, is the slope of the linear fitting between different volumes of water and the NMR signal, dimensionless; is the NMR signal of water samples with different volumes, dimensionless; is the volume of different water samples in milliliters (ml).

[0098] In getting After that, you can When the volume of the water sample in the sample is known, the volume of the water sample in the sample can be calculated; or when the volume of the water sample in the sample is known, the amount of nuclear magnetic signal corresponding to the volume of the water sample can be calculated.

[0099] FIG3 (b) is a methane fitting calibration spectrum, wherein the abscissa is the gas drive pressure, and the ordinate is the nuclear magnetic resonance spectrum signal corresponding to each gas drive pressure. Specifically, a 3.9 ml cavity sample is selected, and the display device 1 is used to control the simulation test device 3 to set the test core sample conditions to a confining pressure of 30 MPa and a temperature of 25°C, and the sample is placed in the second core chamber 31. The display device is used to set different gas drive pressures of the second pressure pump 42, and the third valve 43 and the third valve 43 are opened to continuously introduce methane gas. The test obtains the change of the nuclear magnetic resonance signal at different gas drive pressures after the 3.9 ml cavity is filled with methane, and the linear relationship between different gas drive pressures and the nuclear magnetic resonance signal of methane (or other hydrocarbon gas) per unit pressure per unit volume under different gas drive pressures is obtained. When the linear fitting degree reaches more than 99%, the following fitting curve formula is obtained:

[0100] ;

[0101] in, is the linear fitting slope of the methane NMR signal per unit pressure and per unit volume at different gas drive pressures, dimensionless; —NMR signal of methane per unit pressure and per unit volume at different gas drive pressures, dimensionless; is the signal quantity of NMR spectrum under different gas driving pressures, dimensionless; is the volume of methane standard sample, in milliliters (ml); represents different gas drive pressures, in MPa.

[0102] In getting After that, you can In the case of Alternatively, you can In the case of , the volume of methane corresponding to .

[0103] After completing the calibration of the water signal or the methane signal, the third valve 43 needs to be closed, and the fourth valve 53 needs to be kept open to recover the methane gas until the nuclear magnetic resonance spectrum signal amount is 0, and then the fourth valve 53 is closed to recover the methane to end the process.

[0104] In this embodiment, considering that the nuclear magnetic resonance signal spectrum can be divided into one-dimensional spectrum and two-dimensional spectrum, the embodiment of the present invention provides two methods for evaluating the helium-rich natural gas accumulation efficiency based on one-dimensional nuclear magnetic resonance spectrum and two-dimensional nuclear magnetic resonance spectrum, respectively, to test the changes in the signal quantity and quality of the nuclear magnetic resonance spectrum under different gas drive pressures: specifically, the third valve 43, the fourth valve 53 and the fifth valve 54 are opened through the display device, the second pressure pump 42 is set to different gas drive pressures (the maximum pressure is 30 MPa), the pressure pump is turned on, and the nuclear magnetic resonance signal spectrum of a 1:1 mixed helium and methane mixed gas is tested at different pressures to drive water (the maximum pressure is 30 MPa), and the nuclear magnetic resonance signal quantity and quality under different gas drive pressures are measured. , to plot NMR signal spectra of water displacement at different gas displacement pressures. Then, close third valve 43, and continue opening fourth and fifth valves 53 and 54 to recycle gas and water until the NMR spectrum signal reaches 0. Then, close fourth and fifth valves 53 and 54, completing the recovery.

[0105] in, Figure 4 FIG5 is a one-dimensional spectrum of the nuclear magnetic resonance signal of the water-displacing gas mixture of helium and methane; FIG6 is a two-dimensional spectrum of the nuclear magnetic resonance signal of the water-displacing gas mixture of helium and methane; Figure 4 In the figure, the horizontal axis is the relaxation time and the vertical axis is the NMR signal. As the relaxation time increases, the NMR signal gradually decreases after reaching the peak value. Figure 5 shows the two-dimensional spectra of the NMR signals of helium and methane mixed gas driving water at different gas driving pressures, among which Figure 5 (a) is the NMR signal under saturated water sample; Figure 5 (b) is the NMR signal under the pressure of AMPa (4MPa); Figure 5 (c) is the NMR signal under the pressure of BMPa (8MPa); Figure 5 (d) is the NMR signal under the pressure of CMPa (12MPa) ; Figure 5 (e) is the nuclear magnetic resonance signal under a pressure of DMPa (16MPa); Figure 5 (f) is the nuclear magnetic resonance signal under a pressure of EMPa (20MPa); Figure 5 (g) is the nuclear magnetic resonance signal under a pressure of FMPa (24MPa); Figure 5 (h) is the nuclear magnetic resonance signal under a pressure of GMPa (28MPa); Figure 5 (i) is the nuclear magnetic resonance signal under a pressure of HMPa (30MPa); in each figure, the horizontal axis is the transverse relaxation time, the vertical axis is the longitudinal relaxation time, the white solid line frame is water, and the white dotted line frame is methane.

[0106] Through the above steps, the geological data of the underground reservoir rock sample to be evaluated obtained in step 110 can be obtained. The following steps 120-150 are used to process the data to evaluate the helium-rich natural gas accumulation efficiency, which will be described in detail.

[0107] Step 120: Calculate the volume of the target fluid after the target fluid is saturated in the underground reservoir rock sample to be evaluated by vacuuming it based on the dry weight NMR spectrum signal, the slope of the linear fitting between the target fluid and the NMR signal at different volumes, and the NMR spectrum signal after vacuuming it to saturate the target fluid.

[0108] In this embodiment, taking water as an example, the volume of water after the underground reservoir rock sample to be evaluated is vacuum-saturated with water can be calculated using the following formula:

[0109]

[0110] in, It is the volume of water after the rock sample of the underground reservoir to be evaluated is vacuum-saturated with water.

[0111] In this embodiment, the two methods for evaluating the helium-rich natural gas reservoir efficiency based on one-dimensional nuclear magnetic resonance spectroscopy and two-dimensional nuclear magnetic resonance spectroscopy also have different methods for calculating the gas drive efficiency. The following describes the evaluation of the helium-rich natural gas reservoir efficiency based on one-dimensional nuclear magnetic resonance spectroscopy through an optional embodiment:

[0112] In an optional embodiment, determining the gas flooding efficiency of the underground reservoir rock sample to be evaluated at different gas flooding pressures based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid in step 130 may include:

[0113] The gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the one-dimensional nuclear magnetic resonance spectrum is calculated based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid, the mass of the sample after vacuum-saturated with the target fluid, the mass of the sample at different gas drive pressures, and the first calculation formula.

[0114] In this embodiment, taking water as an example, the first calculation formula may be:

[0115]

[0116] in, is the gas flooding efficiency of the underground reservoir rock sample to be evaluated at different gas flooding pressures in the one-dimensional nuclear magnetic resonance spectrum; It is the mass after vacuum saturation with water; is the mass of the sample at different gas driving pressures; is the density of water; The volume of water after the rock sample of the underground reservoir to be evaluated is saturated with water by vacuum;

[0117] After obtaining the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the one-dimensional nuclear magnetic resonance spectrum, it is necessary to determine the reservoir pressure of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum. Accordingly, determining the reservoir pressure based on the gas drive efficiency at different gas drive pressures in step 140 may include:

[0118] According to the gas drive efficiency under different gas drive pressures and their corresponding gas drive pressures, a gas drive pressure-gas drive efficiency diagram is drawn.

[0119] In the gas drive pressure-gas drive efficiency diagram, when the slope of the curve is no greater than a first preset threshold, the corresponding gas drive pressure is taken as the reservoir forming pressure.

[0120] Figure 6 This is a gas drive pressure-gas drive efficiency diagram of the helium-rich natural gas reservoir efficiency evaluation method provided by the embodiment of the present invention. Figure 6 This embodiment is described as follows:

[0121] In this embodiment, the first preset threshold can be set to 0.1, 0.07, 0.05, etc., and is not limited here. The essence of "taking the corresponding gas drive pressure as the reservoir pressure when the slope of the curve is not greater than the first preset threshold" is to take the corresponding gas drive pressure as the reservoir pressure when the slope of the curve approaches 0. Specifically, Figure 6 In the equation ( ), the horizontal axis is the gas drive pressure, and the vertical axis is the gas drive efficiency. If the slope of the curve corresponding to point G is not greater than the first preset threshold, then the gas drive pressure corresponding to point G is the reservoir forming pressure.

[0122] After determining the reservoir formation pressure of the underground reservoir rock sample to be evaluated under the one-dimensional nuclear magnetic resonance spectrum, it is necessary to calculate the reservoir formation efficiency under the one-dimensional nuclear magnetic resonance spectrum based on the reservoir formation pressure. Accordingly, in step 150, the reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the reservoir formation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum, which may include:

[0123] According to the reservoir formation pressure of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum, the volume of helium in the underground reservoir rock sample to be evaluated under the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum is determined.

[0124] The accumulation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum is calculated based on the volume of helium in the underground reservoir rock sample to be evaluated, the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid, and a second calculation formula.

[0125] The reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum.

[0126] In this embodiment, taking water and methane as an example, the volume of helium in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum can be determined by solving the following formulas simultaneously:

[0127]

[0128]

[0129]

[0130] in, is the volume of water in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum; is the volume of methane in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum; The slope of the linear fitting between different volumes of water and NMR signal; is the reservoir formation pressure in one-dimensional nuclear magnetic resonance spectroscopy; is the linear fitting slope of the methane NMR signal per unit pressure and per unit volume at different gas drive pressures; is the signal amount of NMR spectrum under different gas driving pressures.

[0131] Accordingly, the second calculation formula can be:

[0132]

[0133] in, is the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum; is the volume of helium in the underground reservoir rock sample to be evaluated at the reservoir formation pressure.

[0134] After determining the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum, the reservoir formation efficiency of the underground reservoir rock sample to be evaluated can be evaluated according to the content in Table 1. For details, see Table 1, the reservoir formation efficiency evaluation table:

[0135] Table 1. Evaluation table of reservoir formation efficiency

[0136] Accumulation rate (E accumulation) / % ＜10 10-25 ＞25 evaluate Difference good excellent

[0137] Referring to Table 1, if the accumulation rate is less than the first evaluation threshold, the accumulation efficiency of the underground reservoir rock sample to be evaluated is determined to be poor; if the accumulation rate is not less than the first evaluation threshold and not greater than the second evaluation threshold, the accumulation efficiency of the underground reservoir rock sample to be evaluated is determined to be good; if the accumulation rate is greater than the second evaluation threshold, the accumulation efficiency of the underground reservoir rock sample to be evaluated is determined to be excellent. The first evaluation threshold and the second evaluation threshold can be determined based on multiple experimental test data of different types of rock samples. Specifically, the first evaluation threshold can be 9%, 10%, or 11%; the second evaluation threshold can be 24%, 25%, 26%, etc., and are not limited here.

[0138] After explaining the evaluation of the helium-rich natural gas reservoir efficiency based on one-dimensional nuclear magnetic resonance spectroscopy, the following describes the evaluation of the helium-rich natural gas reservoir efficiency based on two-dimensional nuclear magnetic resonance spectroscopy through another optional embodiment:

[0139] In an optional embodiment, determining the gas flooding efficiency of the underground reservoir rock sample to be evaluated at different gas flooding pressures based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid in step 130 may include:

[0140] The gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the two-dimensional nuclear magnetic resonance spectrum is calculated based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid, the nuclear magnetic signal quantity of the target fluid at different gas drive pressures, the linear fitting slope of the target fluid at different volumes and the nuclear magnetic signal quantity, and the third calculation formula.

[0141] In this embodiment, taking water as an example, the third calculation formula may be:

[0142]

[0143] in, is the gas flooding efficiency of the underground reservoir rock sample to be evaluated at different gas flooding pressures in the two-dimensional nuclear magnetic resonance spectrum; is the nuclear magnetic signal of water under different gas driving pressures.

[0144] After determining the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the two-dimensional nuclear magnetic resonance spectrum, the reservoir pressure of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum can be determined by referring to the explanation in the above step 140, which will not be repeated here.

[0145] After determining the reservoir formation pressure of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum, in step 150, the reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the reservoir formation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum. This may include:

[0146] According to the reservoir formation pressure of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum, the target hydrocarbon gas volume of the underground reservoir rock sample to be evaluated under the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum is determined.

[0147] Based on the NMR signal quantity of the target fluid at different gas drive pressures and the linear fitting slope of the target fluid volume and the NMR signal quantity, the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional NMR spectrum is calculated.

[0148] The accumulation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum is calculated based on the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum-saturated with the target fluid, the volume of the target hydrocarbon gas in the underground reservoir rock sample to be evaluated at the accumulation pressure in the two-dimensional nuclear magnetic resonance spectrum, the volume of the target fluid in the underground reservoir rock sample to be evaluated at the accumulation pressure in the two-dimensional nuclear magnetic resonance spectrum, and the fourth calculation formula.

[0149] The reservoir formation efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum.

[0150] In this embodiment, taking methane as an example, the methane volume of the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum can be determined by the following calculation formula:

[0151]

[0152] in, is the volume of methane in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum; is the signal amount of methane at the accumulation pressure in the two-dimensional nuclear magnetic resonance spectrum; is the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum.

[0153] Among them, the signal amount of methane at the reservoir pressure in the two-dimensional nuclear magnetic resonance spectrum can be used to calibrate the two-dimensional spectrum to obtain the distribution range of methane (or other hydrocarbon gases) in the sample, which can be calculated by the distribution range of methane (or other hydrocarbon gases) in the two-dimensional spectrum at the sample reservoir pressure.

[0154] The volume of water in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum can be calculated using the following calculation formula, taking water as an example:

[0155]

[0156] in, is the volume of water in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum.

[0157] Accordingly, the fourth calculation formula can be:

[0158]

[0159] in, is the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum.

[0160] After determining the accumulation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the accumulation rate. Reference may be made to other related embodiments mentioned above and will not be repeated here.

[0161] In summary, compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0162] 1. The helium-rich natural gas "reservoir pressure" and "reservoir formation rate" obtained in the present invention based on the changes in the nuclear magnetic resonance spectral signal of a mixture of helium and methane (or other hydrocarbon gases) displacing water (or other fluids) at different pressures are obtained under conditions that simulate actual geological history and have a certain degree of accuracy.

[0163] 2. Currently, there are no related invention patents for evaluating the efficiency of helium-rich natural gas accumulation. The embodiments of the present invention are proposed for the first time and are not limited by different rock types. They are generally applicable to all types of rock reservoirs currently available.

[0164] 3. The regression of different types of rock reservoirs in the embodiment of the present invention is directly affected by external fluids and is not affected by external representations and human factors, so the evaluation results are more scientific and objective.

[0165] 4. The embodiments of the present invention are simple to operate, have clear principles, produce accurate results, are easy to implement, and can be widely promoted.

[0166] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0167] The following are embodiments of the display device of the present invention. For details not fully described therein, reference may be made to the corresponding method embodiments described above.

[0168] Figure 7 Schematic diagram of a display device provided by an embodiment of the present invention. Figure 7As shown, the display device 7 of this embodiment includes: a processor 70, a memory 71, and a computer program 72 stored in the memory 71 and executable on the processor 70. When the processor 70 executes the computer program 72, the steps in each of the above-mentioned helium-rich natural gas reservoir efficiency evaluation method embodiments are implemented, such as Figure 1 Alternatively, the processor 70 implements the functions of the modules / units in the above-mentioned device embodiments when executing the computer program 72 .

[0169] Exemplarily, the computer program 72 may be divided into one or more modules / units, which are stored in the memory 71 and executed by the processor 70 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 72 in the display device 7.

[0170] The display device 7 can be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The display device 7 can include, but is not limited to, a processor 70 and a memory 71. It will be understood by those skilled in the art that Figure 7 It is only an example of the display device 7 and does not constitute a limitation of the display device 7. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the display device may also include input and output devices, network access devices, buses, etc.

[0171] The processor 70 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0172] The memory 71 can be an internal storage unit of the display device 7, such as the hard disk or memory of the display device 7. The memory 71 can also be an external storage device of the display device 7, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped on the display device 7. Furthermore, the memory 71 can include both the internal storage unit of the display device 7 and an external storage device. The memory 71 is used to store the computer program and other programs and data required by the display device. The memory 71 can also be used to temporarily store data that has been output or is about to be output.

[0173] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0174] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0175] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0176] In the embodiments provided by the present invention, it should be understood that the disclosed devices / display devices and methods can be implemented in other ways. For example, the device / display device embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0177] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0178] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0179] If the integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the processes in the above-described method embodiments by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-described helium-rich natural gas reservoir efficiency evaluation methods. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a removable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium.

[0180] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for evaluating the efficiency of helium-rich natural gas accumulation, characterized in that: include: Obtaining geological data of the underground reservoir rock sample to be evaluated; wherein the geological data includes dry weight nuclear magnetic resonance spectrum signal, linear fitting slope of different volumes of target fluid and nuclear magnetic signal quantity, and nuclear magnetic resonance spectrum signal after vacuum saturation of target fluid; Calculate the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuumed and saturated with the target fluid according to the dry weight nuclear magnetic resonance spectrum signal, the linear fitting slope of the target fluid with different volumes and the nuclear magnetic resonance signal, and the nuclear magnetic resonance spectrum signal after the target fluid is vacuumed and saturated with the target fluid; Determining the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is evacuated and saturated with the target fluid; Determine the reservoir pressure based on the gas drive efficiency at different gas drive pressures; Wherein, the determination of the reservoir forming pressure based on the gas drive efficiency under different gas drive pressures includes: According to the gas drive efficiency under different gas drive pressures and their corresponding gas drive pressures, a gas drive pressure-gas drive efficiency diagram is drawn; In the gas drive pressure-gas drive efficiency diagram, when the slope of the curve is not greater than a first preset threshold, the corresponding gas drive pressure is used as the reservoir forming pressure; evaluating the reservoir forming efficiency of the underground reservoir rock sample to be evaluated according to the reservoir forming pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum pumping; The method of evaluating the reservoir forming efficiency of the underground reservoir rock sample to be evaluated according to the reservoir forming pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum pumping includes: Determine the volume of helium in the underground reservoir rock sample to be evaluated at the reservoir pressure in the one-dimensional nuclear magnetic resonance spectrum according to the reservoir formation pressure of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum; Wherein, the volume of the helium is determined by the following formula: in, is the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum; is the volume of target hydrocarbon gas in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the one-dimensional nuclear magnetic resonance spectrum; is the volume of helium in the underground reservoir rock sample to be evaluated at the reservoir formation pressure; The volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum pumping; is the mass of the target fluid after vacuum saturation; is the mass of the underground reservoir rock sample to be evaluated under the different gas drive pressures; is the density of the target fluid; The slope of the linear fitting of different volumes of target fluid and NMR signal; is the reservoir forming pressure in one-dimensional NMR spectrum; It is the linear fitting slope of the target hydrocarbon gas NMR signal quantity per unit pressure and unit volume at different gas drive pressures; is the signal amount of NMR spectrum under different gas driving pressures; Calculate the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum according to the volume of helium in the underground reservoir rock sample to be evaluated, the volume of the target fluid after the underground reservoir rock sample to be evaluated is evacuated and saturated with the target fluid, and a second calculation formula; Wherein, the second calculation formula is: in, is the reservoir formation rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum; The reservoir forming efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the reservoir forming rate of the underground reservoir rock sample to be evaluated in the one-dimensional nuclear magnetic resonance spectrum.

2. The method for evaluating the efficiency of helium-rich natural gas accumulation according to claim 1, characterized in that: The geological data also includes the mass of the target fluid after vacuum saturation and the mass of the underground reservoir rock sample to be evaluated under different gas drive pressures; The method of determining the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuumed and saturated with the target fluid comprises: According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuumed and saturated with the target fluid, the mass of the target fluid after being vacuumed and saturated, the mass of the underground reservoir rock sample to be evaluated at the different gas drive pressures and the first calculation formula, the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the one-dimensional nuclear magnetic resonance spectrum is calculated.

3. The method for evaluating the efficiency of helium-rich natural gas accumulation according to claim 2, characterized in that: The geological data also includes different gas drive pressures and linear fitting slopes of target hydrocarbon gas nuclear magnetic signal quantities per unit pressure and per unit volume at different gas drive pressures; The first calculation formula is: in, is the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the one-dimensional nuclear magnetic resonance spectrum; is the mass of the target fluid after vacuum saturation; is the mass of the underground reservoir rock sample to be evaluated under the different gas drive pressures; is the density of the target fluid; It is the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuumed and saturated with the target fluid.

4. The method for evaluating the efficiency of helium-rich natural gas accumulation according to claim 1, characterized in that: The geological data also includes the nuclear magnetic signal quantity of the target fluid under different gas drive pressures; The method of determining the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuumed and saturated with the target fluid comprises: Calculate the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the nuclear magnetic resonance two-dimensional spectrum according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is evacuated and saturated with the target fluid, the nuclear magnetic signal amount of the target fluid at different gas drive pressures, the linear fitting slope of the target fluid with different volumes and the nuclear magnetic signal amount, and a third calculation formula; The reservoir forming efficiency of the underground reservoir rock sample to be evaluated can be evaluated according to the reservoir forming pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum pumping. The following method can also be used: Determine the target hydrocarbon gas volume of the underground reservoir rock sample to be evaluated at the accumulation pressure in the two-dimensional nuclear magnetic resonance spectrum according to the accumulation pressure of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum; Wherein, the target hydrocarbon gas volume is determined by the following formula: in, is the volume of target hydrocarbon gas in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum; is the signal amount of the target hydrocarbon gas at the reservoir pressure in the two-dimensional nuclear magnetic resonance spectrum; is the reservoir forming pressure in the two-dimensional nuclear magnetic resonance spectrum; Calculating the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir forming pressure in the two-dimensional nuclear magnetic resonance spectrum according to the nuclear magnetic signal amount of the target fluid at the different gas drive pressures and the linear fitting slope of the target fluid with different volumes and the nuclear magnetic signal amount; Calculate the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum according to the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid by vacuum, the volume of the target hydrocarbon gas of the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum, the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum, and a fourth calculation formula; Wherein, the fourth calculation formula is: in, is the reservoir formation rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum; is the volume of the target fluid in the underground reservoir rock sample to be evaluated at the reservoir formation pressure in the two-dimensional nuclear magnetic resonance spectrum; The reservoir forming efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the reservoir forming rate of the underground reservoir rock sample to be evaluated in the two-dimensional nuclear magnetic resonance spectrum.

5. The method for evaluating the efficiency of helium-rich natural gas accumulation according to claim 4, characterized in that: The third calculation formula is: in, is the gas drive efficiency of the underground reservoir rock sample to be evaluated at different gas drive pressures in the two-dimensional nuclear magnetic resonance spectrum; is the nuclear magnetic signal amount of the target fluid under the different gas drive pressures.

6. A display 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, the steps of the method for evaluating the accumulation efficiency of helium-rich natural gas as described in any one of claims 1 to 5 are implemented.

7. A helium-rich natural gas reservoir efficiency evaluation system, characterized in that: It comprises a vacuum saturation device, a simulation test device, a gas supply device, a recovery device and the display device as claimed in claim 6.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the accumulation efficiency of helium-rich natural gas as described in any one of claims 1 to 5 are implemented.

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