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

Abstract

Provided in the present application are a helium-rich natural gas reservoir-forming efficiency evaluation method and system, an apparatus and a storage medium. The method comprises: acquiring geological data of a subsurface reservoir rock sample to be evaluated; on the basis of a dry weight nuclear magnetic resonance spectrum signal, a linear fitting slope of different volumes of a target fluid and nuclear magnetic signal quantities, and a nuclear magnetic resonance spectrum signal obtained after the target fluid has been vacuum-saturated, calculating the volume of the vacuum-saturated target fluid in said subsurface reservoir rock sample; on the basis of the volume of the vacuum-saturated target fluid in said subsurface reservoir rock sample, determining the gas drive efficiency and reservoir-forming pressure of said subsurface reservoir rock sample under different gas drive pressure; and, on the basis of the reservoir-forming pressure and the volume of the target fluid in said subsurface reservoir rock sample, evaluating the reservoir-forming efficiency of said subsurface reservoir rock sample. The present application simulates real geological historical conditions by means of analyzing change conditions under different pressure, thereby improving the accuracy of evaluation results of helium-rich natural gas reservoir-forming efficiency.

Description

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

[0001] This patent application claims priority to Chinese Patent Application No. CN 202410717220.X, filed on June 4, 2024. The disclosure of the prior application is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of oil and gas exploration, and in particular to a helium-rich natural gas reservoir efficiency evaluation method, device, system and storage medium. BACKGROUND

[0003] Helium (He) has special physical and chemical properties such as high thermal conductivity and strong chemical inertness, and is widely used in national defense industry and high-tech fields, and has become a very important strategic resource. Helium generally exists in the form of gas molecules, and its mass is light and its diffusion is strong, so the geological theory research and exploration and development technology research of helium as a natural gas resource become more and more important.

[0004] However, there are great differences between helium and natural gas in the micro-mechanism of migration and accumulation after the generation of helium, and the helium gas discovered at present is mostly formed into helium-rich natural gas with methane and other types of gas and eventually accumulates, and there is no geological example of pure helium gas accumulation. Before the helium-rich natural gas reservoir accumulates, different types of fluids may exist in the rock reservoir, such as magmatic hydrothermal fluid, formation water and other types of gas. With the generation and migration of helium-rich natural gas into the rock reservoir, the original fluids in the rock reservoir will be driven out, and finally the helium-rich natural gas reservoir is formed. The existing research mainly studies the helium-rich natural gas from the aspects of geological structure, lithology distribution, genetic source and resource quantity evaluation, and the research on the microscale mechanism of helium-rich natural gas accumulation, especially the accumulation efficiency (the proportion of helium gas in the gas reservoir), is still in the exploratory stage, and there is a lack of qualitative and quantitative characterization parameters. TECHNICAL PROBLEM

[0005] The embodiments of the present application provide a helium-rich natural gas reservoir efficiency evaluation method, device, system and storage medium to solve the problem that there is a lack of effective evaluation of the reservoir efficiency of natural gas at the present stage. TECHNICAL SOLUTION

[0006] In a first aspect, the embodiments of the present application provide a helium-rich natural gas reservoir efficiency evaluation method, comprising:

[0007] obtaining geological data of a rock sample of an underground reservoir to be evaluated; wherein the geological data includes a dry weight nuclear magnetic resonance spectrum signal, a slope of a linear fitting of different volume target fluids and nuclear magnetic signals, and a nuclear magnetic resonance spectrum signal after vacuum saturation of a target fluid;

[0008] According to the dry weight nuclear magnetic resonance spectrum signal, the fitting slope of the different volume target fluid and the nuclear magnetic signal amount line, and the nuclear magnetic resonance spectrum signal after the target fluid is vacuum saturated, the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum saturated is calculated;

[0009] According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum saturated, the gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures is determined;

[0010] Based on the gas displacement efficiency under different gas displacement pressures, the accumulation pressure is determined;

[0011] According to the accumulation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum saturated, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated.

[0012] In a possible implementation, based on the gas displacement efficiency under different gas displacement pressures, the accumulation pressure is determined, including:

[0013] According to the gas displacement efficiency under different gas displacement pressures and the corresponding gas displacement pressure, a gas displacement pressure-gas displacement efficiency graph is drawn;

[0014] In the gas displacement pressure-gas displacement efficiency graph, when the curve slope is not greater than a first preset threshold, the corresponding gas displacement pressure is taken as the accumulation pressure.

[0015] In a possible implementation, the geological data further includes the mass after the target fluid is vacuum saturated and the mass of the underground reservoir rock sample to be evaluated under different gas displacement pressures;

[0016] According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum saturated, the gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures is determined, including:

[0017] According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum saturated, the mass after the target fluid is vacuum saturated, the mass of the underground reservoir rock sample to be evaluated under different gas displacement pressures, and a first calculation formula, the gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures in the nuclear magnetic resonance one-dimensional spectrum is calculated.

[0018] In a possible implementation, according to the accumulation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is vacuum saturated, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated, including:

[0019] According to the accumulation pressure of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance one-dimensional spectrum, the volume of helium in the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance one-dimensional spectrum is determined;

[0020] 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 under vacuum, and a second calculation formula, the accumulation efficiency of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance one-dimensional spectrum is calculated.

[0021] According to the accumulation efficiency of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance one-dimensional spectrum, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated.

[0022] In one possible implementation, the geological data further includes different gas drive pressures and different gas drive pressure unit pressure unit volume target hydrocarbon gas nuclear magnetic signal amount linear fitting slopes;

[0023] The first calculation formula is:

[0024] Wherein, E P驱1 is the gas drive efficiency of the underground reservoir rock sample to be evaluated under different gas drive pressures in the nuclear magnetic resonance one-dimensional spectrum; m 饱 is the mass after being saturated with the target fluid under vacuum; m P is the mass of the underground reservoir rock sample to be evaluated under different gas drive pressures; p is the density of the target fluid; V L is the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid under vacuum;

[0025] The volume of helium is determined by the following formula: V PL1 +V PTG1 +V P氦气 =V L K1×V PL1 +P 成藏1 ×K2×V PTG1 =S P

[0026] Wherein, V PL1 is the volume of the target fluid in the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance one-dimensional spectrum; V PTG1 is the volume of the target hydrocarbon gas in the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance one-dimensional spectrum; V P氦气 is the volume of helium in the underground reservoir rock sample to be evaluated under the accumulation pressure; K1 is the linear fitting slope of different volumes of target fluid and nuclear magnetic signal; P 成藏1 is the accumulation pressure in the nuclear magnetic resonance one-dimensional spectrum; K2 is the linear fitting slope of different gas drive pressures and different gas drive pressure unit pressure unit volume target hydrocarbon gas nuclear magnetic signal; S P is the nuclear magnetic resonance spectrum signal amount under different gas drive pressures;

[0027] The second calculation formula is:

[0028] wherein, E 成藏1 is the accumulation rate of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance one-dimensional spectrum.

[0029] In a possible implementation, the geological data further includes the nuclear magnetic signal amount of the target fluid under different gas drive pressures;

[0030] According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid under vacuum, the gas drive efficiency of the underground reservoir rock sample to be evaluated under different gas drive pressures is determined, including:

[0031] According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid under vacuum, the nuclear magnetic signal amount of the target fluid under different gas drive pressures, and the linear fitting slope of different volumes of the target fluid and the nuclear magnetic signal amount and the third calculation formula, the gas drive efficiency of the underground reservoir rock sample to be evaluated under different gas drive pressures in the nuclear magnetic resonance two-dimensional spectrum is calculated;

[0032] According to the accumulation pressure and the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid under vacuum, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated, including:

[0033] According to the accumulation pressure of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance two-dimensional spectrum, the volume of methane of the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance two-dimensional spectrum is determined;

[0034] According to the nuclear magnetic signal amount of the target fluid under different gas drive pressures and the linear fitting slope of different volumes of the target fluid and the nuclear magnetic signal amount, the volume of the target fluid in the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance two-dimensional spectrum is calculated;

[0035] According to the volume of the target fluid after the underground reservoir rock sample to be evaluated is saturated with the target fluid under vacuum, the volume of the target hydrocarbon gas of the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance two-dimensional spectrum, the volume of the target fluid in the underground reservoir rock sample to be evaluated under the accumulation pressure in the nuclear magnetic resonance two-dimensional spectrum, and the fourth calculation formula, the accumulation rate of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance two-dimensional spectrum is calculated;

[0036] According to the accumulation rate of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance two-dimensional spectrum, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated.

[0037] In a possible implementation, the third calculation formula is:

[0038] wherein, EP驱2 to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S PL to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S

[0039] The target hydrocarbon gas volume is determined by the following formula:

[0040] Wherein, V PTG2 to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S PTG to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S 成藏2 to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S

[0041] The fourth calculation formula is: E 成藏2 = (V L -V PTG2 -V PL2 ) / V L x 100

[0042] Wherein, E 成藏2 to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S PL2 to evaluate the gas displacement efficiency of the underground reservoir rock sample under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S

[0043] In a second aspect, the embodiments of the present application provide a display device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method of the first aspect or any possible implementation manner of the first aspect when executing the computer program.

[0044] In a third aspect, the embodiments of the present application provide 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 of the second aspect.

[0045] In a fourth aspect, the embodiments of the present application provide a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the method of the first aspect or any possible implementation manner of the first aspect when executed by a processor. Advantages

[0046] The application provides a helium-rich natural gas reservoir forming efficiency evaluation method, device, system and storage medium. Compared with the traditional method, the evaluation method provided by the application has certain accuracy in obtaining the reservoir forming pressure and reservoir forming rate of the helium-rich natural gas by analyzing the change under different pressures and simulating the real geological history conditions. Moreover, the application adopts a complete system method, studies the direct influence of external fluid on different types of rock reservoirs, is not affected by external representation and artificial factors, and the evaluation result is more scientific and objective. The application provides a method for evaluating the helium gas reservoir forming efficiency of a rock sample in an underground reservoir to be evaluated, fills the gap in the field, provides an effective means for detecting the helium gas reservoir forming efficiency, improves the evaluation accuracy of the helium-rich natural gas reservoir forming efficiency, and is not limited by the type of rock. The method is universally applicable to various types of rock reservoirs known at present. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or related technical descriptions. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0048] Fig. 1 is a structural schematic diagram of a helium-rich natural gas reservoir forming efficiency evaluation system provided by the application;

[0049] Fig. 2 is an implementation flowchart of a helium-rich natural gas reservoir forming efficiency evaluation method provided by the application;

[0050] Figs. 3(a)-(b) are fitting calibration spectrum diagrams of the helium-rich natural gas reservoir forming efficiency evaluation method provided by the application;

[0051] Fig. 4 is a water-driven nuclear magnetic resonance signal one-dimensional spectrum diagram of the helium-rich natural gas reservoir forming efficiency evaluation method provided by the application;

[0052] Figs. 5(a)-(i) are water-driven nuclear magnetic resonance signal two-dimensional spectrum diagrams of the helium-rich natural gas reservoir forming efficiency evaluation method provided by the application;

[0053] Fig. 6 is a gas drive pressure-gas drive efficiency diagram of the helium-rich natural gas reservoir forming efficiency evaluation method provided by the application;

[0054] Fig. 7 is a schematic diagram of a display device provided by the application. Embodiments of the application

[0055] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, technologies, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

[0056] For the purpose of making the objectives, technical solutions and advantages of the present application clearer, the following will be described with reference to the accompanying drawings through specific embodiments.

[0057] For the purpose of making the objectives, technical solutions and advantages of the present application clearer, the following will be described with reference to the accompanying drawings through specific embodiments.

[0058] Fig. 1 is a structural schematic diagram of a helium-rich natural gas reservoir efficiency evaluation system according to an embodiment of the present application.

[0059] Before evaluating the helium-rich natural gas reservoir efficiency, the underground reservoir rock sample to be evaluated generally needs to be pretreated to obtain geological data of the underground reservoir rock sample to be evaluated. Specifically, the underground reservoir rock sample to be evaluated can be pretreated by the vacuum saturation device 2, the simulation test device 3, the gas supply device 4 and the recovery device 5 in the system shown in Fig. 1 to obtain the geological data, and then the geological data can be analyzed by the display device 1 in Fig. 1 to evaluate the helium-rich natural gas reservoir efficiency.

[0060] In one specific embodiment, as shown in Fig. 1, the helium-rich natural gas reservoir efficiency evaluation system can further include a base 6. The base 6 can be cuboid-shaped to make the bottom weight of the system large and the landing area large, so as to ensure the stability of the system instruments during the experiment. The base 6 connects and supports the display device 1, the vacuum saturation device 2, the simulation test device 3, the gas supply device 4 and the recovery device 5.

[0061] The vacuum saturation device 2 can include 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 pressurizing pump 27. The vacuum saturation device 2 is used to vacuum saturate the core with water (or other fluid) according to the experimental purpose or the formation pressure, simulate the state of the saturated water (or other fluid) in the core under the required or real formation conditions of the experimental purpose, and determine the nuclear magnetic signal amount linear fitting slope of different volumes of water and the nuclear magnetic resonance spectrum signal after vacuum saturation of water.

[0062] The simulation test device 3 can include a nuclear magnetic resonance device 3(a) and an online weighing device 3(b). The nuclear magnetic resonance device 3(a) can include 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 nuclear magnetic resonance device 3(a) can control the coil magnetic field in the test space where the first magnet 34, the second magnet 35, and the rock sample are located, so that the sample is in a stable and uniform magnetic field environment, ensuring the accuracy of the nuclear magnetic signal measurement. Moreover, through the core holder 36 and the heating coil 32, the temperature and confining pressure of the core sample can be simulated according to the experimental purpose or the formation conditions. The online weighing device 3(b) is connected to the second core chamber 31 through an electronic cable, and is used to monitor the mass change of the sample in the core chamber in real time.

[0063] The gas supply device 4 can include a replaceable gas tank 41, a second pressurizing pump 42, a third valve 43, and a second pressure sensor 44. The gas supply device 4 is used to supply different proportions of helium and methane (or other hydrocarbon gases) to the entire experimental equipment according to the experimental purpose or the formation conditions. Through the second pressurizing pump 42, different gas drive pressures are set, and the supplied gas can drive the water (or other fluid) in the core in a fully saturated water (or other fluid) state.

[0064] The recovery device 5 can include a gas recovery tank 51, a liquid fluid recovery tank 52, a fourth valve 53, and a fifth valve 54. The recovery device 5 is used to recover the water (or other liquid fluid) and gas flowing out of each core chamber during the experimental test.

[0065] The display device 1 is a terminal equipment 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. In addition to the display screen, the display device 1 also integrates a control system that can control the entire test process and display the nuclear magnetic resonance spectrum of the rock sample under different states, the mass change of the sample, and the calculated signal amount, analyze the dynamic changes of the helium-rich natural gas drive reservoir in the rock sample, calculate the “reservoir pressure” and “reservoir rate”, and evaluate the reservoir efficiency of the helium-rich natural gas in the rock sample.

[0066] Specifically, in combination with the helium-rich natural gas reservoir efficiency evaluation system shown in FIG. 1, in one embodiment, the helium-rich natural gas reservoir efficiency evaluation method provided by the present application can include steps (1) to (7), which are described as follows.

[0067] Step (1): Obtain a sample

[0068] Obtain a target formation rock sample and pretreat it to obtain an underground reservoir rock sample to be evaluated.

[0069] Step (2): Dry the sample

[0070] Dry the sample in a drying oven to remove water from the sample, measure the dry weight of the sample, and test the dry sample to obtain a nuclear magnetic resonance spectrum signal.

[0071] Step (3): Calibrate water (or other fluid) signals and methane (or other hydrocarbon gas) signals in the rock sample

[0072] Use standard water (or other fluid) samples to calculate and determine the relationship between different volumes of water (or other fluids) and nuclear magnetic resonance signal amounts, and use standard methane (or other hydrocarbon gas) samples to determine the relationship between different gas drive pressures and the amount of methane (or other hydrocarbon gas) nuclear magnetic resonance signal per unit pressure and per unit volume under different gas drive pressures.

[0073] Step (4): Vacuum saturation of the sample with water (or other fluid)

[0074] Place the sample in a vacuum saturation device 2, set the pressure in the vacuum environment after vacuumizing to saturate the sample with water (or other fluid), measure the saturated water (or other fluid) quality, and test the water-saturated (or other fluid) sample nuclear magnetic resonance spectrum signal.

[0075] Step (5): Helium and methane (or other hydrocarbon gas) mixed gas drives water (or other fluid) in the sample

[0076] Test the nuclear magnetic resonance spectrum of the helium and methane (or other hydrocarbon gas) mixed gas (the mixing ratio is set according to the actual formation conditions or experimental purposes) driving water (or other fluid) under different gas drive pressures, measure the nuclear magnetic resonance spectrum signal amount and quality change under different gas drive pressures, and draw the nuclear magnetic resonance spectrum graph under different gas drive pressures.

[0077] Step (6): Calculate the reservoir pressure and accumulation rate

[0078] According to the nuclear magnetic resonance signal amounts of the samples obtained in steps (2), (3), (4) and (5) in different states, the gas drive efficiency corresponding to different gas drive pressures is calculated, a gas drive pressure-gas drive efficiency point-line graph is drawn, and the gas drive pressure corresponding to the gradually-tending-to-0 slope of the curve in the graph is the "reservoir-forming pressure". The "reservoir-forming rate" is calculated based on the nuclear magnetic resonance spectrum signal amount, sample mass and other data at the "reservoir-forming pressure".

[0079] Step (7): Accurate evaluation of the reservoir-forming efficiency of the helium-rich natural gas reservoir

[0080] Based on the test data of multiple different types of rock samples, the "reservoir-forming rate" is divided into three ranges of excellent, good and poor, and the reservoir-forming efficiency of the helium-rich natural gas in the core obtained through the test is evaluated according to the ranges.

[0081] The method for evaluating the reservoir-forming efficiency of the helium-rich natural gas provided in the application is further described below through the following embodiments.

[0082] FIG. 2 is an implementation flowchart of the method for evaluating the reservoir-forming efficiency of the helium-rich natural gas provided in an embodiment of the application; the method provided in the embodiment is described in detail below in combination with FIGS. 1 and 2. Specifically, the method includes steps 110 to 150, which are described as follows.

[0083] Step 110: Obtain the geological data of the rock sample of the underground reservoir to be evaluated; wherein the geological data includes the dry weight nuclear magnetic resonance spectrum signal, the linear fitting slope of the nuclear magnetic signal amount of different volumes of target fluid, and the nuclear magnetic resonance spectrum signal after the target fluid is saturated by vacuumizing.

[0084] In order to obtain the rock sample of the underground reservoir to be evaluated, the rock sample of the target stratum to be evaluated can be collected, a complete large rock sample is selected, and a cylindrical sample with a diameter of about 2.5 cm and a length of 5 cm is obtained by water cutting or wire cutting, which can be used as the rock sample of the underground reservoir to be evaluated. How to obtain the geological data of the rock sample of the underground reservoir to be evaluated is described in detail below. It should be noted that, in the following description, water is used as an example of a liquid for the convenience of description, which does not constitute a limitation on the application; that is, the person skilled in the art can replace water with other fluids to obtain other technical solutions, which do not deviate from the inventive concept of the application. Similarly, in the following description, methane is used as an example of a gas, which also does not constitute a limitation on the application, and the person skilled in the art can replace it with other alkane gases.

[0085] The steps of obtaining the geological data of the rock sample are as follows. Two samples (sample one and sample two) are taken, sample one 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 24h, the purpose is to remove the moisture in sample one. Then sample one is placed in the second core chamber 31, and the display device 1 controls the simulation test device 3 to set the test core sample conditions as follows: confining pressure is HMPa, temperature is 25°C; wherein H is a parameter, which can be set according to needs, such as 29, 29.5, 30, etc., which is not limited here. The dry weight m dry of sample one is tested, and the dry weight nuclear magnetic resonance spectrum signal S dry is obtained.

[0086] Sample one is placed in the first core chamber 23 of the vacuum saturation device 2, the first valve 22 is opened, and after 1h of vacuum pumping by the vacuum pump, the first valve 22 is closed. The display device 1 sets the saturation water pressure of the first pressure pump 27 to 30MPa, and the valve 2 is opened. The sample is saturated in a vacuum environment for 24h. Then sample one is taken out and placed in the second core chamber 31, keeping all valves closed. The display device 1 controls the simulation test device 3 to set the test core sample conditions as follows: confining pressure is 30MPa, temperature is 25°C. The mass m 饱 of the sample after vacuum saturation is measured, and the nuclear magnetic resonance spectrum signal S 饱 of the sample after vacuum saturation is tested. 饱 .

[0087] The water signal and methane signal of sample two are calibrated. Specifically, the calibration process is explained below in conjunction with FIG. 3(a) and FIG. 3(b).

[0088] FIG. 3(a) is a fitting calibration spectrum of water. In FIG. 3(a), the horizontal coordinate is the water volume, and the vertical coordinate is the nuclear magnetic resonance spectrum signal amount corresponding to each water volume. Specifically, different volumes of water samples (water samples can be pure water, or water samples can be configured according to actual formation water conditions, and other fluids are the same) such as 0.05ml, 0.6ml, 1ml, 2ml and 3ml can be selected. The display device 1 controls the simulation test device 3 to set the test core sample conditions as follows: confining pressure is 30MPa, temperature is 25°C, and sample two is placed in the second core chamber 31. The linear relationship between the nuclear magnetic signal and the water volume under this condition is tested, and the linear fitting degree needs to reach more than 99% to obtain the linear relationship between the nuclear magnetic signal and the water quality under this parameter; when the linear fitting degree reaches more than 99%, the following fitting curve formula is obtained: L = K1V L1

[0089] Wherein, K1 is the linear fitting slope of different volumes of water and nuclear magnetic signal amount, dimensionless; S L is the nuclear magnetic signal amount of different volumes of water samples, dimensionless; VL1 The volume of different water samples is given in milliliters (ml).

[0090] After obtaining K1, you can go to S L Given the volume of the water sample, the volume of the water sample in the sample can be calculated; or, given the volume of the water sample in the sample, the corresponding NMR signal quantity can be calculated.

[0091] Figure 3(b) shows the methane fitting calibration spectrum, with the horizontal axis representing the gas driving pressure and the vertical axis representing the NMR signal quantity corresponding to each gas driving pressure. Specifically, a 3.9 ml cavity sample (sample three) can be selected. 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 sample three is placed in the second core chamber 31. The second pressurization pump 42 is set to different gas driving pressures through the display device, and the third valve 43 and the third valve 44 are opened to continuously introduce methane gas. The changes in NMR signal quantity under different gas driving pressures after the 3.9 ml cavity is filled with methane are tested, and the linear relationship between different gas driving pressures and the NMR signal quantity of methane (or other hydrocarbon gases) per unit pressure and unit volume under different gas driving pressures is obtained. After the linear fitting degree reaches more than 99%, the following fitting curve formula is obtained: S TG =S P / V TG标 S TG =K2P

[0092] Where K2 is the slope of the linear fitting of the methane NMR signal per unit pressure and per unit volume under different gas driving pressures, which is dimensionless; S TG —Quantity of methane NMR signal per unit pressure and unit volume under different gas driving pressures, dimensionless; S P V represents the nuclear magnetic resonance spectral signal quantity under different gas driving pressures, which is dimensionless; TG标 , where is the volume of the methane standard sample in milliliters (ml); P represents different gas driving pressures in megapascals (MPa).

[0093] After obtaining K2, we can proceed with the given S TG In the case of V, the calculation is obtained. TG标 Alternatively, given V TG标 In this case, the S corresponding to that volume of methane is calculated. TG .

[0094] After completing the calibration of the water or methane signal, the third valve 43 needs to be closed, and the fourth valve 53 needs to be kept open to recover methane gas until the nuclear magnetic resonance spectrum signal is 0. Then, the fourth valve 53 is closed, and the recovery process ends.

[0095] In view of the fact that the nuclear magnetic resonance signal spectrum can be divided into one-dimensional spectrum and two-dimensional spectrum, the present application provides two methods for evaluating the helium-rich natural gas reservoir efficiency based on the one-dimensional spectrum and the two-dimensional spectrum of nuclear magnetic resonance, respectively. The nuclear magnetic resonance spectrum signal amount and quality under different gas drive pressures can be tested by the following steps: opening the third valve 43, the fourth valve 53 and the fifth valve 54 through the display device, setting the second pressure pump 42 to generate different gas drive pressures (the maximum pressure is 30 MPa); opening the pressure pump, testing the nuclear magnetic resonance signal spectrum of the helium and methane mixed gas with a mixing ratio of 1:1 under different pressures for driving water (the maximum pressure is 30 MPa), and measuring the nuclear magnetic resonance spectrum signal amount and quality m P , under different gas drive pressures to draw the nuclear magnetic resonance signal spectrum diagram of driving water under different gas drive pressures; then, closing the third valve 43, continuously opening the fourth valve 53 and the fifth valve 54 to recover the gas and water until the nuclear magnetic resonance spectrum signal amount is 0, closing the fourth valve 53 and the fifth valve 54, and ending the recovery.

[0096] Through the above steps, the spectrum diagrams shown in FIGS. 4 and 5 can be obtained. FIG. 4 is a one-dimensional spectrum diagram of the nuclear magnetic resonance signal of the helium and methane mixed gas for driving water, and FIG. 5 is a two-dimensional spectrum diagram of the nuclear magnetic resonance signal of the helium and methane mixed gas for driving water. In FIG. 4, the abscissa is the relaxation time, and the ordinate is the nuclear magnetic resonance signal amount; with the increase of the relaxation time, the nuclear magnetic resonance signal amount gradually decreases after reaching the peak value. FIG. 5 shows the two-dimensional spectrum diagram of the nuclear magnetic resonance signal of the helium and methane mixed gas for driving water under different gas drive pressures; wherein, FIG. 5(a) is the nuclear magnetic resonance signal of the saturated water sample; FIG. 5(b) is the nuclear magnetic resonance signal under a pressure of AMPa (for example, 4 MPa); FIG. 5(c) is the nuclear magnetic resonance signal under a pressure of BMPa (for example, 8 MPa); FIG. 5(d) is the nuclear magnetic resonance signal under a pressure of CMPa (for example, 12 MPa); FIG. 5(e) is the nuclear magnetic resonance signal under a pressure of DMPa (for example, 16 MPa); FIG. 5(f) is the nuclear magnetic resonance signal under a pressure of EMPa (for example, 20 MPa); FIG. 5(g) is the nuclear magnetic resonance signal under a pressure of FMPa (for example, 24 MPa); FIG. 5(h) is the nuclear magnetic resonance signal under a pressure of GMPa (for example, 28 MPa); FIG. 5(i) is the nuclear magnetic resonance signal under a pressure of HMPa (for example, 30 MPa); in each figure, the abscissa is the transverse relaxation time, the ordinate is the longitudinal relaxation time, the white solid line box is water, and the white dashed line box is methane.

[0097] Through the above steps, the geological data of the underground reservoir rock sample to be evaluated in step 110 can be obtained. The geological data is processed by steps 120-150 to evaluate the helium-rich natural gas reservoir efficiency. Steps 120-150 are described in detail as follows.

[0098] Step 120: calculating the volume of the target fluid saturated in the rock sample of the underground reservoir to be evaluated after vacuum saturation according to the NMR spectrum signal of the dry sample, the linear fitting slope of the target fluid and the NMR signal amount, and the NMR spectrum signal of the target fluid after vacuum saturation.

[0099] Taking water as an example (i.e., the target fluid is water), the volume of water saturated in the rock sample of the underground reservoir to be evaluated after vacuum saturation can be calculated by the following formula: L 饱 干

[0100] wherein, V L is the volume of water saturated in the rock sample of the underground reservoir to be evaluated after vacuum saturation.

[0101] The helium-rich natural gas accumulation efficiency can be evaluated based on the NMR one-dimensional spectrum and the NMR two-dimensional spectrum, and the calculation method of the gas drive efficiency is different in the two methods. The following describes the evaluation of the helium-rich natural gas accumulation efficiency based on the NMR one-dimensional spectrum through an optional embodiment:

[0102] In an optional embodiment, the gas drive efficiency of the rock sample of the underground reservoir to be evaluated under different gas drive pressures can be determined according to the volume of the target fluid saturated in the rock sample of the underground reservoir to be evaluated after vacuum saturation in step 130, which can include:

[0103] The gas drive efficiency of the rock sample of the underground reservoir to be evaluated under different gas drive pressures in the NMR one-dimensional spectrum can be calculated according to the volume of the target fluid saturated in the rock sample of the underground reservoir to be evaluated after vacuum saturation, the mass of the target fluid after vacuum saturation, the mass of the sample under different gas drive pressures, and the first calculation formula.

[0104] In this embodiment, taking water as an example (i.e., the target fluid is water), the first calculation formula can be:

[0105] wherein, E P驱1 is the gas drive efficiency of the rock sample of the underground reservoir to be evaluated under different gas drive pressures in the NMR one-dimensional spectrum; m 饱 is the mass of the water after vacuum saturation; m P is the mass of the sample under different gas drive pressures; p is the density of water; and V L is the volume of water saturated in the rock sample of the underground reservoir to be evaluated after vacuum saturation.

[0106] ​​​After obtaining the gas displacement efficiency of the rock sample of the underground reservoir to be evaluated under different gas displacement pressures in the nuclear magnetic resonance one-dimensional spectrum, the accumulation pressure of the rock sample of the underground reservoir to be evaluated under the nuclear magnetic resonance one-dimensional spectrum needs to be determined. Correspondingly, determining the accumulation pressure based on the gas displacement efficiency under different gas displacement pressures in step 140 can include:

[0107] According to the gas displacement efficiency under different gas displacement pressures and the corresponding gas displacement pressures, a gas displacement pressure-gas displacement efficiency graph is drawn.

[0108] In the gas displacement pressure-gas displacement efficiency graph, the corresponding gas displacement pressure when the curve slope is not greater than the first preset threshold is taken as the accumulation pressure.

[0109] FIG. 6 is a gas displacement pressure-gas displacement efficiency graph of the helium-rich natural gas accumulation efficiency evaluation method provided by the embodiment of the present application. The present embodiment will be described below in combination with FIG. 6:

[0110] In the present embodiment, the first preset threshold can be set to 0.1, 0.07, 0.05, etc., which is not limited herein. The essence of “taking the corresponding gas displacement pressure when the curve slope is not greater than the first preset threshold as the accumulation pressure” is to take the corresponding gas displacement pressure when the curve slope approaches 0 as the accumulation pressure. Specifically, in FIG. 6, the abscissa is the gas displacement pressure, and the ordinate is the gas displacement efficiency. The curve slope corresponding to point G is not greater than the first preset threshold, so the gas displacement pressure corresponding to point G is the accumulation pressure.

[0111] After determining the accumulation pressure of the rock sample of the underground reservoir to be evaluated under the nuclear magnetic resonance one-dimensional spectrum, the accumulation rate under the nuclear magnetic resonance one-dimensional spectrum needs to be calculated according to the accumulation pressure; correspondingly, evaluating the accumulation efficiency of the rock sample of the underground reservoir to be evaluated in step 150 according to the accumulation pressure and the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid after being vacuumized can include:

[0112] According to the accumulation pressure of the rock sample of the underground reservoir to be evaluated in the nuclear magnetic resonance one-dimensional spectrum, the volume of helium in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the nuclear magnetic resonance one-dimensional spectrum is determined.

[0113] According to the volume of helium in the rock sample of the underground reservoir to be evaluated, the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid after being vacuumized, and the second calculation formula, the accumulation rate of the rock sample of the underground reservoir to be evaluated in the nuclear magnetic resonance one-dimensional spectrum is calculated.

[0114] The accumulation efficiency of the rock sample of the underground reservoir to be evaluated is evaluated according to the accumulation rate of the rock sample of the underground reservoir to be evaluated in the nuclear magnetic resonance one-dimensional spectrum.

[0115] In the present embodiment, taking water and methane as examples, the volume of helium in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the one-dimensional spectrum of nuclear magnetic resonance can be determined by solving the following equations simultaneously: V PL1 +V PTG1 +V P氦气 =V L K1×V PL1 +P 成藏1 ×K2×V PTG1 =S P

[0116] wherein V PL1 is the volume of water in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the one-dimensional spectrum of nuclear magnetic resonance; V PTG1 is the volume of methane in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the one-dimensional spectrum of nuclear magnetic resonance; K1 is the slope of the linear fitting of different volumes of water and nuclear magnetic signal; P 成藏1 is the accumulation pressure in the one-dimensional spectrum of nuclear magnetic resonance; K2 is the slope of the linear fitting of different gas drive pressures and unit volume of methane under different gas drive pressures; S P is the nuclear magnetic resonance spectrum signal amount under different gas drive pressures.

[0117] Correspondingly, the second calculation formula can be:

[0118] wherein E 成藏1 is the accumulation rate of the rock sample of the underground reservoir to be evaluated in the one-dimensional spectrum of nuclear magnetic resonance; V P氦气 is the volume of helium in the rock sample of the underground reservoir to be evaluated under the accumulation pressure.

[0119] After determining the accumulation rate of the rock sample of the underground reservoir to be evaluated in the one-dimensional spectrum of nuclear magnetic resonance, the accumulation efficiency of the rock sample of the underground reservoir to be evaluated can be evaluated according to the content in Table 1. Specifically, refer to Table 1 for the accumulation efficiency evaluation table:

[0120] Table 1 Accumulation efficiency evaluation table

[0121] Referring to Table 1, if the accumulation rate is less than the first evaluation threshold, it is determined that the accumulation efficiency of the underground reservoir rock sample to be evaluated is poor; if the accumulation rate is not less than the first evaluation threshold and not greater than the second evaluation threshold, it is determined that the accumulation efficiency of the underground reservoir rock sample to be evaluated is good; and if the accumulation rate is greater than the second evaluation threshold, it is determined that the accumulation efficiency of the underground reservoir rock sample to be evaluated is excellent. The first evaluation threshold and the second evaluation threshold can be determined based on experimental test data of multiple different types of rock samples. Specifically, the first evaluation threshold can be 9%, 10%, 11%, and the second evaluation threshold can be 24%, 25%, 26%, and the like, which are not limited herein.

[0122] After the evaluation and explanation of the helium-rich natural gas accumulation efficiency based on the one-dimensional spectrum of nuclear magnetic resonance, the following will describe the evaluation of the helium-rich natural gas accumulation efficiency based on the two-dimensional spectrum of nuclear magnetic resonance through another optional embodiment:

[0123] In an optional embodiment, the determination of the gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures according to the volume of the target fluid saturated in the underground reservoir rock sample to be evaluated after vacuumizing in step 130 can include:

[0124] The gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures in the two-dimensional spectrum of nuclear magnetic resonance is calculated according to the volume of the target fluid saturated in the underground reservoir rock sample to be evaluated after vacuumizing, the nuclear magnetic signal amount of the target fluid under different gas displacement pressures, and the linear fitting slope of different volumes of the target fluid and the nuclear magnetic signal amount and the third calculation formula.

[0125] In this embodiment, taking water as an example, the third calculation formula can be:

[0126] wherein, E P驱2 is the gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures in the two-dimensional spectrum of nuclear magnetic resonance; S PL is the nuclear magnetic signal amount of water under different gas displacement pressures.

[0127] After determining the gas displacement efficiency of the underground reservoir rock sample to be evaluated under different gas displacement pressures in the two-dimensional spectrum of nuclear magnetic resonance, the accumulation pressure of the underground reservoir rock sample to be evaluated in the two-dimensional spectrum of nuclear magnetic resonance can be determined by referring to the explanation and description in the above step 140, which will not be repeated here.

[0128] After determining the accumulation pressure of the underground reservoir rock sample to be evaluated in the two-dimensional spectrum of nuclear magnetic resonance, in step 150, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated according to the accumulation pressure and the volume of the target fluid saturated in the underground reservoir rock sample to be evaluated after vacuumizing can include:

[0129] According to the accumulation pressure of the rock sample of the underground reservoir to be evaluated in the NMR two-dimensional spectrum, the volume of the target hydrocarbon gas of the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum is determined.

[0130] According to the NMR signal amount of the target fluid under different gas drive pressures and the linear fitting slope of different volumes of the target fluid and the NMR signal amount, the volume of the target fluid in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum is calculated.

[0131] According to the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid under vacuum, the volume of the target hydrocarbon gas of the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum, the volume of the target fluid in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum, and the fourth calculation formula, the accumulation efficiency of the rock sample of the underground reservoir to be evaluated in the NMR two-dimensional spectrum is calculated.

[0132] According to the accumulation efficiency of the rock sample of the underground reservoir to be evaluated in the NMR two-dimensional spectrum, the accumulation efficiency of the rock sample of the underground reservoir to be evaluated is evaluated.

[0133] In this embodiment, taking methane as an example, the volume of methane of the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum can be determined by the following calculation formula:

[0134] Wherein, V PTG2 is the volume of methane in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum; S PTG is the signal amount of methane under the accumulation pressure in the NMR two-dimensional spectrum; P 成藏2 is the accumulation pressure in the NMR two-dimensional spectrum.

[0135] Wherein, the signal amount of methane under the accumulation pressure in the NMR two-dimensional spectrum can be obtained by using the distribution range of methane (or other hydrocarbon gas) in the sample under the sample accumulation pressure in the two-dimensional spectrum.

[0136] Taking water as an example, the volume of water in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum can be calculated by the following calculation formula:

[0137] Wherein, V PL2 is the volume of water in the rock sample of the underground reservoir to be evaluated under the accumulation pressure in the NMR two-dimensional spectrum.

[0138] Correspondingly, the fourth calculation formula can be: E 成藏2 = (V L-V PTG2 -V PL2 ) / V L ×100

[0139] E 成藏2 is the accumulation efficiency of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance two-dimensional spectrum.

[0140] After determining the accumulation efficiency of the underground reservoir rock sample to be evaluated in the nuclear magnetic resonance two-dimensional spectrum, the accumulation efficiency of the underground reservoir rock sample to be evaluated is evaluated based on the accumulation efficiency. For reference, the other related embodiments described above will not be repeated here.

[0141] In summary, compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0142] 1. The "accumulation pressure" and "accumulation efficiency" of the helium-rich natural gas obtained by the embodiments of the present application based on the change of the nuclear magnetic resonance spectrum signal amount of the mixed gas of helium and methane (or other hydrocarbon gas) driving water (or other fluid) under different pressures are obtained under the simulation of real geological history conditions, and have a certain accuracy.

[0143] 2. The evaluation method proposed in the present application is not limited by the type of rock, and is generally applicable to various types of rock reservoirs known at present.

[0144] 3. The embodiments of the present application study the direct influence of external fluid on different types of rock reservoirs, are not affected by external characterization and human factors, and the evaluation results are more scientific and objective.

[0145] 4. The embodiments of the present application are simple in operation, clear in principle, accurate in result, easy to implement, and can be widely promoted and applied.

[0146] It should be understood that the size of the serial number of each step in the above embodiments does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and the serial number of each step should not constitute any limitation on the implementation process of the embodiments of the present application.

[0147] The following is an embodiment of the display device of the present application. For details not described in detail, reference can be made to the corresponding method embodiments described above.

[0148] FIG. 7 is a schematic diagram of a display device according to an embodiment of the present application. As shown in FIG. 7, the display device 7 according to the embodiment includes a processor 70, a memory 71, and a computer program 72 stored in the memory 71 and capable of running on the processor 70. The processor 70 implements the steps in the above various embodiments of the method for evaluating the accumulation efficiency of a helium-rich natural gas reservoir when executing the computer program 72, such as steps 110 to 150 shown in FIG. 1. Alternatively, the processor 70 implements the functions of each module / unit in the display device embodiment when executing the computer program 72.

[0149] For example, the computer program 72 can be divided into one or more modules / units, which are stored in the memory 71 and executed by the processor 70 to implement the technical solutions provided by the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 72 in the display device 7.

[0150] The display device 7 can be a desktop computer, a notebook computer, a handheld computer, a cloud server, or the like. The display device 7 can include, but is not limited to, the processor 70 and the memory 71. Those skilled in the art can understand that FIG. 7 is only an example of the display device 7, and does not limit the display device 7; the display device can include more or fewer components than those shown, or combine certain components, or include different components, for example, the display device according to the present application can also include an input / output device, a network access device, a bus, and the like.

[0151] The processor 70 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, or the like. The general-purpose processor can be a microprocessor or other any normal processor.

[0152] The memory 71 can be an internal storage unit of the display device 7, such as a hard disk or a 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 card, and the like equipped on the display device 7. Further, the memory 71 can also include both the internal storage unit and the external storage device of the display device 7. 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 to be output.

[0153] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified; in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs; that is, the internal structure of the display device is divided into different functional units or modules to complete all or part of the above-described functions. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit; the above-mentioned integrated unit can be realized in the form of hardware or in the form of software functional unit. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the present application. The specific working process of the device, unit and module in the rich-helium natural gas reservoir efficiency evaluation system provided by the present application can refer to the corresponding process in the foregoing method embodiment, which will not be described here.

[0154] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0155] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art 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 application.

[0156] In the embodiments of the present application, it should be understood that the disclosed apparatus / display apparatus and method can be implemented in other manners. For example, the described apparatus / display apparatus embodiments are merely schematic. Taking the division of the modules or units as an example, the division can be changed in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or the displayed or discussed mutual couplings or direct couplings or communication connections, can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0157] The units provided as separate components can or can not be physically separate, and the components provided as units can or can not be physical units; that is, they can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0158] In addition, each functional unit in the various embodiments of the present application can be integrated into one processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be implemented in the form of hardware, or in the form of a software functional unit.

[0159] The integrated module / unit, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such an understanding, all or part of the flow of the above-described embodiment methods can also be implemented by a computer program instructing related hardware to complete; the computer program can be stored in a computer readable storage medium, and when the processor executes the computer program, the steps of each of the above-mentioned rich helium natural gas reservoir efficiency evaluation method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable file or some intermediate form. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0160] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for evaluating the accumulation efficiency of a helium-rich natural gas, characterized in that, The method comprises: obtaining geological data of a rock sample of a to-be-evaluated underground reservoir; wherein the geological data comprises a dry-weight nuclear magnetic resonance spectrum signal, a slope of a linear fitting of different volumes of target fluid and nuclear magnetic signal, and a nuclear magnetic resonance spectrum signal after the target fluid is saturated by vacuumizing; calculating a volume of the target fluid after the rock sample of the to-be-evaluated underground reservoir is saturated by vacuumizing, according to the dry-weight nuclear magnetic resonance spectrum signal, the slope of the linear fitting of different volumes of target fluid and nuclear magnetic signal, and the nuclear magnetic resonance spectrum signal after the target fluid is saturated by vacuumizing; determining gas displacement efficiency of the rock sample of the to-be-evaluated underground reservoir under different gas displacement pressures, according to the volume of the target fluid after the rock sample of the to-be-evaluated underground reservoir is saturated by vacuumizing; determining a reservoir-forming pressure based on the gas displacement efficiency under different gas displacement pressures; evaluating reservoir-forming efficiency of the rock sample of the to-be-evaluated underground reservoir, according to the reservoir-forming pressure and the volume of the target fluid after the rock sample of the to-be-evaluated underground reservoir is saturated by vacuumizing.

2. The method according to claim 1, wherein, The method further comprises: drawing a gas displacement pressure-gas displacement efficiency graph according to the gas displacement efficiency under different gas displacement pressures and the corresponding gas displacement pressures; determining the reservoir-forming pressure as the gas displacement pressure corresponding to a curve slope not greater than a first preset threshold in the gas displacement pressure-gas displacement efficiency graph.

3. The method according to claim 1, wherein, The geological data further comprises a mass after the target fluid is saturated by vacuumizing and a mass of the rock sample of the to-be-evaluated underground reservoir under different gas displacement pressures; The method further comprises: calculating the gas displacement efficiency of the rock sample of the to-be-evaluated underground reservoir under different gas displacement pressures in a nuclear magnetic resonance one-dimensional spectrum, according to the volume of the target fluid after the rock sample of the to-be-evaluated underground reservoir is saturated by vacuumizing, the mass after the target fluid is saturated by vacuumizing, the mass of the rock sample of the to-be-evaluated underground reservoir under different gas displacement pressures, and a first calculation formula.

4. The method according to claim 3, wherein, The method further comprises: determining a volume of helium in the rock sample of the to-be-evaluated underground reservoir under the reservoir-forming pressure in the nuclear magnetic resonance one-dimensional spectrum, according to the reservoir-forming pressure in the nuclear magnetic resonance one-dimensional spectrum; calculating a reservoir-forming rate in the nuclear magnetic resonance one-dimensional spectrum of the rock sample of the to-be-evaluated underground reservoir, according to the volume of helium in the rock sample of the to-be-evaluated underground reservoir and the volume of the target fluid after the rock sample of the to-be-evaluated underground reservoir is saturated by vacuumizing, and a second calculation formula; evaluating the reservoir-forming efficiency of the rock sample of the to-be-evaluated underground reservoir, according to the reservoir-forming rate in the nuclear magnetic resonance one-dimensional spectrum.

5. The method according to claim 4, wherein, The geological data further comprises different gas displacement pressures and a slope of a linear fitting of different gas displacement pressures and unit pressure unit volume target hydrocarbon gas nuclear magnetic signal. The first calculation formula is: wherein E P驱1 is the gas displacement efficiency of the rock sample of the underground reservoir to be evaluated under different gas displacement pressures in the one-dimensional spectrum of nuclear magnetic resonance; m 饱 is the mass of the target fluid after the vacuum extraction; m P is the mass of the rock sample of the underground reservoir to be evaluated under different gas displacement pressures; p is the density of the target fluid; V L is the volume of the target fluid after the vacuum extraction of the rock sample of the underground reservoir to be evaluated; The volume of the helium is determined by the following formula: V PL1 +V PTG1 +V P氦气 =V L K1 x V PL1 + P 成藏1 K2 x V PTG1 = S P wherein V PL1 is the volume of the target fluid in the rock sample of the subterranean reservoir to be evaluated at the reservoir pressure in the one-dimensional spectrum of nuclear magnetic resonance; V PTG1 is the volume of the target fluid in the rock sample of the subterranean reservoir to be evaluated at the reservoir pressure in the one-dimensional spectrum of nuclear magnetic resonance V is the volume of the target hydrocarbon gas in the rock sample; V P氦气 K1 is the slope of the linear fit of the different volumes of the target fluid to the NMR signal; P 成藏1 K2 is the slope of the linear fit of the different gas drive pressures to the NMR signal per unit volume of the target hydrocarbon gas per unit pressure at different gas drive pressures; S P S is the NMR signal at different gas drive pressures. The second calculation formula is: wherein E 成藏1 is the accumulation rate of the rock sample of the underground reservoir to be evaluated in the one-dimensional spectrum of nuclear magnetic resonance.

6. The method according to claim 1, wherein, The geological data further includes the nuclear magnetic signal amount of the target fluid under different gas drive pressures; The gas drive efficiency of the rock sample of the underground reservoir to be evaluated under different gas drive pressures is determined according to the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid under vacuum, and the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid under vacuum, the nuclear magnetic signal amount of the target fluid under different gas drive pressures, and the linear fitting slope of the different volumes of the target fluid and the nuclear magnetic signal amount and a third calculation formula. The gas drive efficiency of the rock sample of the underground reservoir to be evaluated under different gas drive pressures in the nuclear magnetic resonance two-dimensional spectrum is calculated according to the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid under vacuum, the nuclear magnetic signal amount of the target fluid under different gas drive pressures, and the linear fitting slope of the different volumes of the target fluid and the nuclear magnetic signal amount and a third calculation formula. The reservoir efficiency of the rock sample of the underground reservoir to be evaluated is evaluated according to the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid under vacuum and the reservoir pressure of the rock sample of the underground reservoir to be evaluated in the nuclear magnetic resonance two-dimensional spectrum. The volume of the target hydrocarbon gas of the rock sample of the underground reservoir to be evaluated under the reservoir pressure in the nuclear magnetic resonance two-dimensional spectrum is determined according to the reservoir pressure of the rock sample of the underground reservoir to be evaluated in the nuclear magnetic resonance two-dimensional spectrum. The volume of the target fluid in the rock sample of the underground reservoir to be evaluated under the reservoir pressure in the nuclear magnetic resonance two-dimensional spectrum is calculated according to the volume of the target fluid after the rock sample of the underground reservoir to be evaluated is saturated with the target fluid under vacuum, the volume of the target hydrocarbon gas of the rock sample of the underground reservoir to be evaluated under the reservoir pressure in the nuclear magnetic resonance two-dimensional spectrum, the volume of the target fluid in the rock sample of the underground reservoir to be evaluated under the reservoir pressure in the nuclear magnetic resonance two-dimensional spectrum, and a fourth calculation formula. The reservoir efficiency of the rock sample of the underground reservoir to be evaluated is evaluated according to the reservoir rate of the rock sample of the underground reservoir to be evaluated in the nuclear magnetic resonance two-dimensional spectrum. The fourth calculation formula is: The processor executes the computer program to realize the steps of the method of any one of claims 1 to 7.

7. The method according to claim 6, wherein, The third calculation formula is: wherein E P驱2 is the gas displacement efficiency of the rock sample of the underground reservoir to be evaluated under different gas displacement pressures in the nuclear magnetic resonance two-dimensional spectrum; S PL is the nuclear magnetic signal amount of the target fluid under the different gas displacement pressures. The target hydrocarbon gas volume is determined by the following equation: wherein V PTG2 is the volume of the target hydrocarbon gas in the rock sample of the underground reservoir to be evaluated under the reservoir pressure in the two-dimensional nuclear magnetic resonance spectrum; S PTG is the signal amount of the target hydrocarbon gas under the reservoir pressure in the two-dimensional nuclear magnetic resonance spectrum; P 成藏2 is the reservoir pressure in the two-dimensional nuclear magnetic resonance spectrum; The device comprises a vacuum saturation device, a simulation test device, a gas supply device, a recovery device, and a display device as claimed in claim 8. E 成藏2 = (V L - V PTG2 - V PL2 ) / V L x 100 wherein E 成藏2 is the accumulation rate of the rock sample of the underground reservoir to be evaluated in the NMR two-dimensional spectrum; V PL2 is the volume of the target fluid in the rock sample of the underground reservoir to be evaluated at the accumulation pressure in the NMR two-dimensional spectrum.

8. A display device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that The computer program is executed by the processor to realize the steps of the method of any one of claims 1 to 7.

9. A system for evaluating the accumulation efficiency of a helium-rich natural gas, characterized in that, The computer program is executed by the processor to realize the steps of the method of any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1-9. ​

Images