Method and system for quantitatively evaluating contribution degrees of imbibition, oil washing and energy increasing in huff-puff process

Abstract

The invention relates to a method and system for quantitatively evaluating the contribution degrees of imbibition, oil washing and energy increasing in the huff and puff process, and belongs to the technical field of oil and gas development experiments. The method comprises the following steps: taking a plurality of parallel cores; randomly dividing the plurality of parallel rock cores into three groups, and respectively performing a nuclear magnetic resonance-huff-puff combined test of heavy water fluid at a first time interval, a nuclear magnetic resonance-huff-puff combined test of heavy water fluid at a second time interval and a nuclear magnetic resonance-huff-puff combined test of substitute fluid at the second time interval on the three groups of parallel rock cores, the test parameters of the three groups of nuclear magnetic resonance-huff and puff combined test are the same; the imbibition efficiency, the oil washing efficiency and the energy increasing recovery efficiency of the injected fluid in the huff and puff process are obtained on the basis of the three sets of recovery rates determined by the three sets of combined testing tests; based on the imbibition efficiency, the oil washing efficiency and the energy increasing recovery efficiency in the huff and puff process, the contribution degrees of imbibition, oil washing and energy increasing in the huff and puff process are quantitatively evaluated. Through three groups of core tests, imbibition, oil washing and energy increasing contributions in the huff and puff process are distinguished.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas development experiments, and particularly relates to a method and system for quantitatively evaluating the contribution degrees of imbibition, oil washing and energy increase in a huff and puff process. BACKGROUND

[0002] Hydraulic fracturing is a necessary way to develop unconventional oil and gas (such as shale oil, shale gas and tight oil) at the present stage. Unconventional reservoirs usually have low porosity and low permeability characteristics. The oil and gas resources inside the reservoir are difficult to flow to the wellbore under the energy of the formation. A large amount of fluid is injected into the reservoir at a very high discharge rate (more than 10 m 3 / min) by a ground pump set to form a large number of fractures in the reservoir, so as to promote the oil and gas resources in the reservoir to flow through the hydraulic fractures and then through the wellbore, thereby achieving effective development of unconventional oil and gas resources. Since the hydraulic fracturing technology is mature, the understanding of the fluid in the oil production is limited to the manufacturing of hydraulic fractures and the increase of effective seepage channels of oil and gas in the reservoir. After years of development and research, it is gradually realized that for tight sandstone and conglomerate reservoirs, the fluid has three functions in addition to being the carrier of hydraulic fracturing and manufacturing hydraulic fractures in the reservoir, namely, imbibition displacement oil displacement, oil washing oil displacement and energy increase oil displacement. The imbibition displacement oil displacement refers to the process that the fluid spontaneously imbibes into the pores of the reservoir matrix on both sides of the fracture under the action of capillary force, and displaces the original oil in the pores into the fracture. In addition, part of the fluid contains certain special additives, which can reduce the interfacial tension between the fluid and the oil to a low level, and can disperse oil droplets and promote oil stripping under the action of fluid flow, thereby achieving the effect of oil washing similar to surfactant. This part of the oil displacement is called the oil washing oil displacement of the fluid. Since the fluid has a high pressure during injection into the reservoir, the injection process will compress the oil and increase the elastic energy of the oil in the pores. During the production stage, the oil releases the elastic energy and expands in volume, which will expel part of the oil from the pores. This part of the effect is called the energy increase oil displacement.

[0003] Due to the differences in the above three oil displacement mechanisms, the contributions of the three mechanisms to oil production are quite different in different fluid and oil systems, and the play degree of the three oil displacement mechanisms is also affected by the huff and puff parameters to a certain extent. Therefore, the huff and puff parameter design needs to consider the proportions of the above mechanisms. For example, if the fluid and oil system mainly relies on the energy increase mechanism for oil production, the huff and puff time interval needs to be considered for the propagation and balance of pore pressure in the huff and puff parameter design. If the fluid and oil system mainly relies on oil washing for oil production, the huff and puff time interval needs to be considered for the oil stripping time and the mass transfer time of the effective components in the fluid. Therefore, it is of positive significance to scientifically design the huff and puff parameters to clarify the proportions of imbibition displacement oil displacement, oil washing oil displacement and energy increase oil displacement in a specific fluid and oil system.

[0004] At present, the evaluation of fluid crude oil system mainly focuses on the overall recovery rate, system interfacial tension and fluid viscosity. The overall recovery rate of the fluid is mainly obtained through indoor core swallowing or core imbibition oil displacement experiment. However, the recovery rate obtained by the core swallowing experiment cannot effectively distinguish the proportion of imbibition, oil washing and energy increasing effect in the overall recovery rate, and the core imbibition oil displacement experiment cannot effectively restore the swallowing process, and the pure imbibition oil displacement experiment also cannot distinguish the effects of imbibition and oil washing. SUMMARY

[0005] In view of the above problems, the present application provides a method and system for quantitatively evaluating the contribution degree of imbibition, oil washing and energy increasing in the swallowing process.

[0006] The first object of the present application is to provide a method for quantitatively evaluating the contribution degree of imbibition, oil washing and energy increasing in the swallowing process, comprising:

[0007] a plurality of parallel cores are taken;

[0008] The plurality of parallel cores are randomly divided into three groups, and the three groups of parallel cores are respectively subjected to a first time interval heavy water fluid nuclear magnetic resonance-swallowing combined test, a second time interval heavy water fluid nuclear magnetic resonance-swallowing combined test and a second time interval substitute liquid nuclear magnetic resonance-swallowing combined test. The test parameters in the first time interval heavy water fluid nuclear magnetic resonance-swallowing combined test, the second time interval heavy water fluid nuclear magnetic resonance-swallowing combined test and the second time interval substitute liquid nuclear magnetic resonance-swallowing combined test are the same.

[0009] Based on the first recovery rate determined by the first time interval heavy water fluid nuclear magnetic resonance-swallowing combined test, the second recovery rate determined by the second time interval heavy water fluid nuclear magnetic resonance-swallowing combined test and the third recovery rate determined by the second time interval substitute liquid nuclear magnetic resonance-swallowing combined test, the imbibition efficiency, oil washing efficiency and energy increasing recovery rate of the injected fluid in the swallowing process are obtained.

[0010] Based on the imbibition efficiency, oil washing efficiency and energy increasing recovery rate in the swallowing process, the contribution degree of imbibition, oil washing and energy increasing in the swallowing process is quantitatively evaluated.

[0011] In the embodiment of the present application, the substitute liquid and the crude oil are independent phases, and the volume after compression tends to be close to the original volume. Preferably, the substitute liquid is fluorine oil.

[0012] In the embodiment of the present application, the viscosity of the substitute liquid is the same as that of the heavy water fluid.

[0013] In the embodiment of the present application, the first time interval is smaller than the second time interval.

[0014] In the embodiment of the present application, the first recovery rate determined by the NMR-throughput combined test of the heavy water fluid in the first time interval, the second recovery rate determined by the NMR-throughput combined test of the heavy water fluid in the second time interval, and the third recovery rate determined by the NMR-throughput combined test of the substitute liquid in the second time interval are used to obtain the imbibition efficiency, the oil displacement efficiency, and the energy-enhanced recovery rate of the injected fluid in the throughput process, which comprises:

[0015] The second recovery rate determined by the NMR-throughput combined test of the heavy water fluid in the second time interval is subtracted by the first recovery rate determined by the NMR-throughput combined test of the heavy water fluid in the first time interval to obtain the imbibition efficiency of the injected fluid in the throughput process.

[0016] The first recovery rate determined by the NMR-throughput combined test of the heavy water fluid in the first time interval is subtracted by the third recovery rate determined by the NMR-throughput combined test of the substitute liquid in the second time interval to obtain the oil displacement efficiency of the injected fluid in the throughput process.

[0017] The third recovery rate determined by the NMR-throughput combined test of the substitute liquid in the second time interval is determined as the energy-enhanced recovery rate of the injected fluid in the throughput process.

[0018] In the embodiment of the present application, the specific operation of the NMR-throughput combined test comprises:

[0019] The volume of the crude oil in the oil-saturated state of the core is obtained.

[0020] The test parameters are set to be the same as those in the oil-saturated state of the core, and the NMR signal in the throughput state of the core is tested, wherein the throughput state of the core is the throughput state of the core under the heavy water fluid or the throughput state of the core under the substitute liquid.

[0021] In the embodiment of the present application, the quantitative evaluation of the contribution degree of imbibition, oil displacement, and energy enhancement in the throughput process based on the imbibition efficiency, the oil displacement efficiency, and the energy-enhanced recovery rate in the throughput process comprises:

[0022] The ratio of the imbibition efficiency to the sum of the imbibition efficiency, the oil displacement efficiency, and the energy-enhanced recovery rate is determined as the contribution rate of imbibition in the throughput process.

[0023] The ratio of the oil displacement efficiency to the sum of the imbibition efficiency, the oil displacement efficiency, and the energy-enhanced recovery rate is determined as the contribution rate of oil displacement in the throughput process.

[0024] The ratio of the energy-enhanced recovery rate to the sum of the imbibition efficiency, the oil displacement efficiency, and the energy-enhanced recovery rate is determined as the contribution rate of energy enhancement in the throughput process.

[0025] The contribution degree of imbibition, oil displacement, and energy enhancement in the throughput process is evaluated according to the contribution rate of imbibition, the contribution rate of oil displacement, and the contribution rate of energy enhancement.

[0026] In the embodiment of the present application, the quantitative evaluation of the contribution degree of imbibition, oil displacement and energy increment in the huff and puff process is based on the imbibition efficiency, oil displacement efficiency and energy increment recovery ratio in the huff and puff process, and includes:

[0027] According to the ratio among the imbibition efficiency, oil displacement efficiency and energy increment recovery ratio in the huff and puff process, the contribution degree of imbibition, oil displacement and energy increment in the huff and puff process is evaluated.

[0028] The second object of the present application is to provide a system for quantitative evaluation of the contribution degree of imbibition, oil displacement and energy increment in the huff and puff process, which includes:

[0029] The preparation module is used to take a plurality of parallel cores;

[0030] The combined measurement module is used to randomly divide the plurality of parallel cores into three groups, and the three groups of parallel cores are respectively subjected to the NMR-huff and puff combined test of the first time interval heavy water fluid, the NMR-huff and puff combined test of the second time interval heavy water fluid and the NMR-huff and puff combined test of the second time interval substitute liquid, wherein the test parameters in the NMR-huff and puff combined test of the first time interval heavy water fluid, the NMR-huff and puff combined test of the second time interval heavy water fluid and the NMR-huff and puff combined test of the second time interval substitute liquid are the same;

[0031] The calculation module is used to obtain the imbibition efficiency, oil displacement efficiency and energy increment recovery ratio of the injected fluid in the huff and puff process based on the first recovery ratio determined by the NMR-huff and puff combined test of the first time interval heavy water fluid, the second recovery ratio determined by the NMR-huff and puff combined test of the second time interval heavy water fluid and the third recovery ratio determined by the NMR-huff and puff combined test of the second time interval substitute liquid;

[0032] The evaluation module is used to quantitatively evaluate the contribution degree of imbibition, oil displacement and energy increment in the huff and puff process based on the imbibition efficiency, oil displacement efficiency and energy increment recovery ratio in the huff and puff process.

[0033] In the embodiment of the present application, the calculation module includes an imbibition efficiency submodule, an oil displacement efficiency submodule and an energy increment recovery ratio submodule;

[0034] The imbibition efficiency submodule is used to obtain the imbibition efficiency of the injected fluid in the huff and puff process by subtracting the first recovery ratio determined by the NMR-huff and puff combined test of the first time interval heavy water fluid from the second recovery ratio determined by the NMR-huff and puff combined test of the second time interval heavy water fluid;

[0035] The oil displacement efficiency submodule is used to subtract the third recovery rate of the second time interval displacement fluid determined by the nuclear magnetic resonance-displacement combined test from the first recovery rate of the first time interval heavy water fluid determined by the nuclear magnetic resonance-displacement combined test to obtain the oil displacement efficiency of the injected fluid in the displacement process.

[0036] The energy-enhanced recovery rate submodule is used to determine the third recovery rate of the second time interval displacement fluid determined by the nuclear magnetic resonance-displacement combined test as the energy-enhanced recovery rate of the injected fluid in the displacement process.

[0037] The beneficial effects of the present application are:

[0038] The method and system for quantitatively evaluating the contribution degrees of imbibition, oil displacement and energy enhancement in the displacement process have the following advantages. First, the present application uses the time difference of pressure washing oil and imbibition replacement to design different soaking times (reflected in the setting of the nuclear magnetic resonance-displacement combined test summary time interval) to distinguish the differences between imbibition and oil displacement+energy enhancement. Second, the present application combines the action mechanisms of interfacial tension and capillary force imbibition, uses a liquid that cannot be miscible with crude oil and has a small degree of volume change after compression as a displacement fluid in the injection process, and uses the displacement test of the displacement fluid to measure the recovery rate that can be obtained by pure energy enhancement. Third, the present application uses the displacement experiment to achieve the purpose of quantitatively measuring the recovery rate of energy enhancement. Through the time-differentiated displacement technology, the contribution proportions of different actions can be calculated. Based on the foregoing two points, the present application achieves the distinction between the contributions of imbibition, oil displacement and energy enhancement through three core tests.

[0039] Finally, based on the consideration that it is extremely difficult to directly measure the volume or mass of the crude oil that can be extracted in the displacement process in the existing recovery experiment, the present application uses the nuclear magnetic resonance combined with heavy water and displacement fluid to complete the displacement experiment of the control group. The recovery rate of each group of cores after the displacement experiment is calculated by measuring the total amount of nuclear magnetic signals of the whole core in each stage of the displacement experiment, which greatly simplifies the measurement in the experiment process.

[0040] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the description and claims, and the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative labor.

[0042] Figure 1 A flow chart of a method for quantitatively evaluating the contribution degree of imbibition, oil washing and energy increment in a huff and puff process according to an embodiment of the present application is shown;

[0043] Figure 2 A structural schematic diagram of an apparatus for a NMR-huff and puff test according to an embodiment of the present application is shown;

[0044] Figure 3 A framework diagram of a system for quantitatively evaluating the contribution degree of imbibition, oil washing and energy increment in a huff and puff process according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions and advantages of embodiments of the present application clearer, the following will clearly and completely explain the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0046] As shown in Figure 1 the method for quantitatively evaluating the contribution degree of imbibition, oil washing and energy increment in a huff and puff process according to an embodiment of the present application includes:

[0047] S1, taking a plurality of parallel cores;

[0048] S2, randomly dividing the plurality of parallel cores into three groups, and performing a first time interval heavy water fluid NMR-huff and puff test, a second time interval heavy water fluid NMR-huff and puff test and a second time interval substitute liquid NMR-huff and puff test on the three groups of parallel cores respectively, wherein the test parameters in the first time interval heavy water fluid NMR-huff and puff test, the second time interval heavy water fluid NMR-huff and puff test and the second time interval substitute liquid NMR-huff and puff test are the same;

[0049] S3, obtaining imbibition efficiency, oil washing efficiency and energy increment recovery efficiency of the injected fluid in the huff and puff process based on a first recovery rate determined by the first time interval heavy water fluid NMR-huff and puff test, a second recovery rate determined by the second time interval heavy water fluid NMR-huff and puff test and a third recovery rate determined by the second time interval substitute liquid NMR-huff and puff test;

[0050] S4, quantitatively evaluating the contribution degree of imbibition, oil washing and energy increment in the huff and puff process based on the imbibition efficiency, the oil washing efficiency and the energy increment recovery efficiency in the huff and puff process.

[0051] The setting basis of the method for evaluating the contribution degree of imbibition, oil washing and energy increment in the throughput process of the embodiments of the present application includes:

[0052] Firstly, during the core throughput experiment, because the core scale is relatively small, the differential pressure oil washing process under the reservoir temperature and high pressure gradient is relatively fast (tens of minutes), and the imbibition oil recovery process under the capillary force is relatively slow (usually for several days). Therefore, by using the time difference between the pressure oil washing and the imbibition displacement, different soaking times can be designed to distinguish the difference between imbibition and oil washing + energy increment. This is specifically reflected in the setting of the time interval in the first time interval NMR-throughput combined test and the second time interval NMR-throughput combined test in step S2.

[0053] Secondly, for the proportion of energy increment, the fluid (exemplarily, fracturing fluid in the embodiments of the present application) in the injection process can be replaced by certain alternative fluids, which have the following characteristics: (1) immiscible with crude oil, independent phase (2) high interfacial tension with the crude oil system, which cannot disperse the crude oil and washing oil (3) the contact angle formed by the crude oil-pore surface is close to 90°, and the capillary force difference of the interface is close to zero, so there is no capillary force, and the capillary force imbibition can be ignored (4) the volume coefficient is close to 1, so that the energy increment effect of fluid pressure is concentrated in the oil phase. The above alternative fluids are used to complete the throughput experiment, which can approximately obtain the recovery rate obtained by pure energy increment. This is specifically reflected in the setting of the alternative fluid in the second time interval alternative fluid NMR-throughput combined test in step S2. In some embodiments of the present application, the alternative fluid is fluorine oil, which meets the above conditions.

[0054] In some embodiments of the present application, in step S2, the viscosity of the alternative fluid is the same as that of the heavy water fluid.

[0055] In some embodiments of the present application, in step S2, the first time interval is less than the second time interval.

[0056] In some embodiments of the present application, in step S3, based on the first recovery rate determined by the first time interval heavy water fluid NMR-throughput combined test, the second recovery rate determined by the second time interval heavy water fluid NMR-throughput combined test and the third recovery rate determined by the second time interval alternative fluid NMR-throughput combined test, the imbibition efficiency, oil washing efficiency and energy increment recovery rate of the injected fluid in the throughput process are obtained, including:

[0057] i. The second recovery rate determined by the second time interval heavy water fluid NMR-throughput combined test is subtracted from the first recovery rate determined by the first time interval heavy water fluid NMR-throughput combined test, and the imbibition efficiency of the injected fluid in the throughput process is obtained;

[0058] ii. The oil displacement efficiency of the injected fluid during the huff and puff process is determined by subtracting the third recovery factor determined by the NMR-huff and puff test of the displacing fluid in the second time interval from the first recovery factor determined by the NMR-huff and puff test of the heavy water fluid in the first time interval.

[0059] iii. The enhanced recovery factor of the injected fluid during the huff and puff process is determined by the third recovery factor determined by the NMR-huff and puff test of the displacing fluid in the second time interval.

[0060] The device for the NMR-huff and puff test comprises a plurality of intermediate containers for containing the injected fluid or the displacing fluid, a core holder in communication with the intermediate containers, the core holder being used for clamping the core and applying confining pressure to the core, an ISCO pump connected to the intermediate containers, the ISCO pump being configured to facilitate the liquid in the intermediate containers to enter the core holder, a pressure sensor connected to the core holder, the pressure sensor being linked to a computer, the core holder, the intermediate containers and the pressure sensor being placed in an incubator, and the core holder being capable of being placed in an examination position of an NMR instrument. Figure 2

[0061] The specific operation of the NMR-huff and puff test comprises:

[0062] I. Obtaining the volume of the crude oil in the saturated oil state of the core, specifically comprising:

[0063] a. Saturating the core with the crude oil by placing the core in an intermediate container containing the reservoir crude oil, and then measuring the NMR signal of the core in the saturated oil state;

[0064] b. Measuring the NMR signal of the crude oil with different volumes by setting the same measurement parameters as the core;

[0065] c. Calculating the volume of the crude oil in the saturated state of the core based on the NMR signal of the core in the saturated oil state and the NMR signal of the crude oil with different volumes;

[0066] II. Testing the NMR signal of the core in the huff and puff state by setting the same test parameters as the core in the saturated oil state, wherein the huff and puff state of the core is the huff and puff state of the core under the heavy water fluid or the huff and puff state of the core under the displacing fluid, specifically comprising:

[0067] a. Placing the core in the saturated oil state into the core holder, and placing the heavy water fluid or the displacing fluid into the intermediate container, setting the same test parameters (temperature and confining pressure) as the core in the saturated oil state, and testing the NMR signal of the core in the huff and puff state.

[0068] ​The basis for setting the above-mentioned nuclear magnetic resonance-throughput combined test procedure is:

[0069] The existing recovery experiment generally uses the volume or mass method to measure crude oil. However, the blowout process in the core test is very fast, the total amount of crude oil in the core is limited, and the displacement device also has a certain dead volume, which makes it extremely difficult to directly measure the volume or mass of the crude oil that can be extracted during the throughput process. Accurate measurement of the total amount of crude oil in the core during the throughput process is the premise of accurately distinguishing the contributions of imbibition, oil washing, and energy increase to the oil recovery rate. Therefore, in the embodiments of the present application, an indirect measurement method is used to complete the throughput experiment of the control group by nuclear magnetic resonance, heavy water, and substitute liquid. In the oil washing+imbibition+energy increase and oil washing+energy increase experimental groups, heavy water is used to configure the injected fluid, and in the energy increase experimental group, a substitute liquid is used to replace the injected fluid. Since heavy water and the substitute liquid do not produce nuclear magnetic resonance signals, the signals of the whole core in each stage of the throughput experiment are the signals of the crude oil in the core, and the signal intensity of the nuclear magnetic resonance is linearly related to the total amount of crude oil and has good precision. Therefore, the recovery rate of each group of cores after the throughput experiment can be calculated by the total amount of nuclear magnetic signals of the whole core in each stage of the throughput, and then the recovery rates of imbibition, oil washing, and energy increase can be calculated respectively.

[0070] In some embodiments of the present application, step S4, based on the imbibition efficiency, oil washing efficiency, and energy increase recovery rate in the throughput process, quantitatively evaluates the contribution degree of imbibition, oil washing, and energy increase in the throughput process, including:

[0071] i. determining the ratio of the imbibition efficiency to the sum of the imbibition efficiency, the oil washing efficiency, and the energy increase recovery rate as the contribution rate of imbibition in the throughput process;

[0072] ii. determining the ratio of the oil washing efficiency to the sum of the imbibition efficiency, the oil washing efficiency, and the energy increase recovery rate as the contribution rate of oil washing in the throughput process;

[0073] iii. determining the ratio of the energy increase recovery rate to the sum of the imbibition efficiency, the oil washing efficiency, and the energy increase recovery rate as the contribution rate of energy increase in the throughput process;

[0074] iv. according to the contribution rate of imbibition, the contribution rate of oil washing, and the contribution rate of energy increase in the throughput process, evaluating the contribution degree of imbibition, oil washing, and energy increase in the throughput process.

[0075] In some embodiments of the present application, step S4, based on the imbibition efficiency, oil washing efficiency, and energy increase recovery rate in the throughput process, quantitatively evaluates the contribution degree of imbibition, oil washing, and energy increase in the throughput process, including:

[0076] According to the ratio among the imbibition efficiency, the oil washing efficiency, and the energy increase recovery rate in the throughput process, evaluating the contribution degree of imbibition, oil washing, and energy increase in the throughput process.

[0077] In order to more intuitively embody the method for quantitatively evaluating the imbibition, oil washing and energy increasing contribution degree in the throughput process provided by the embodiments of the present application, the following shows the specific core measurement and pricing process. In the following example, the fluid in the injection process is exemplarily a fracturing fluid, correspondingly, the heavy water fluid is exemplarily a heavy water fracturing fluid, the replacement fluid is exemplarily a fluorine oil, and the materials, reagents and the like used in the following example can be obtained from commercial channels, unless otherwise specified.

[0078] Example 1

[0079] (1) Drill three cylindrical cores with a length of 50 mm and a diameter of 25 mm at the same position of the artificial core, and place the cores in the middle container filled with reservoir crude oil to saturate the crude oil.

[0080] (2) After saturation is completed, number the cores as a, b and c, and measure the T2 relaxation spectrum using the same measurement parameters.

[0081] (3) Measure the T2 signal of 0.5 ml, 1 ml, 2 ml, 3 ml and 4 ml of crude oil using the same parameters as the core measurement, draw a graph of the signal total amount versus the crude oil volume, obtain a straight line of the crude oil volume versus the signal total amount, calculate the slope of the straight line, and obtain the nuclear magnetic signal conversion coefficient under the current measurement parameters. Calculate the crude oil volume Va, Vb and Vc in the saturation state of each core.

[0082] (4) Prepare heavy water with fracturing fluid additives in a field proportion for standby; measure the viscosity of the fracturing fluid, and prepare fluorine oil with the same viscosity as the field fracturing fluid for standby.

[0083] (5) Load the core a into the core holder, set the confining pressure to 10 MPa, and heat the system to the reservoir temperature.

[0084] (6) Close the valve at the outlet end of the holder, inject the heavy water fracturing fluid at a constant pressure of 5 MPa through the plunger pump after 0.1 times Va, close the inlet valve for 20 minutes, remove the inlet valve pipeline, open the inlet valve to release the spray, and complete one round of short interval throughput experiment.

[0085] (7) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, calculate the recovery rate of one round of short interval throughput, i.e. the recovery rate of oil washing and energy increasing effect, from the T2 signal total amount of one round of short interval throughput and the T2 signal total amount of the saturation state; wherein the calculation formula is shown in formula (1).

[0086] Recovery rate = (1 - throughput T2 signal total amount / saturation state T2 signal total amount) * 100% (1)

[0087] (8) Load the core b into the core holder, set the confining pressure to 10 MPa, and heat the system to the reservoir temperature.

[0088] (9) The outlet valve of the holder is closed, and the heavy water fracturing fluid is injected into 0.1 times Vb at a constant pressure of 5 MPa by the plunger pump. After 600 minutes, the inlet valve is closed, the inlet valve pipeline is removed, the inlet valve is opened to release the injection, and one round of long interval injection experiment is completed.

[0089] (10) The confining pressure is unloaded, the core is taken out, the T2 signal of the core is measured with the same parameters, the total amount of T2 signal of one round of long interval injection is compared with the total amount of T2 signal of the saturated state, and the recovery rate of one round of long interval injection, i.e., the recovery rate of the oil washing + imbibition + energy enhancement effect Rb, is calculated according to formula (1).

[0090] (11) The core c is loaded into the core holder, the confining pressure is 10 MPa, and the system is heated to the reservoir temperature.

[0091] (12) The outlet valve of the holder is closed, and the fluorine oil is injected into 0.1 times Vc at a constant pressure of 5 MPa by the plunger pump. After 600 minutes, the inlet valve is closed, the inlet valve pipeline is removed, the inlet valve is opened to release the injection, and one round of long interval injection experiment is completed (the long time interval is equal to the long time interval of the core b).

[0092] (13) The confining pressure is unloaded, the core is taken out, the T2 signal of the core is measured with the same parameters, the total amount of T2 signal of one round of long interval injection is compared with the total amount of T2 signal of the saturated state, and the recovery rate of one round of long interval injection, i.e., the recovery rate of the energy enhancement effect Rc, is calculated according to formula (1).

[0093] (14) Rb-Ra is the imbibition displacement recovery rate (i.e., the imbibition efficiency), Ra-Rc is the oil washing recovery rate (i.e., the oil washing efficiency), and Rc is the energy enhancement recovery rate.

[0094] (15) According to the analysis of the proportion of imbibition, oil washing and energy enhancement in the injection recovery rate, the contribution degree of imbibition, oil washing and energy enhancement in the injection process is quantitatively evaluated, and the specific results are shown in Table 1.

[0095] Example 2

[0096] (1) Three cylindrical cores with a length of 50 mm and a diameter of 25 mm are drilled at the same position of the artificial core, and the cores are placed in the middle container filled with reservoir crude oil to be saturated with crude oil.

[0097] (2) After saturation, the cores are numbered as a, b and c, and the T2 relaxation spectrum is measured with the same measurement parameters.

[0098] (3) Measure the T2 signal of 0.5ml, 1ml, 2ml, 3ml, 4ml volume of crude oil with the same parameters as core measurement, draw the relationship diagram of signal total amount and crude oil volume, get the relationship straight line of crude oil volume and signal total amount, calculate the slope of the straight line, get the conversion coefficient of crude oil volume and current measurement parameter under nuclear magnetic signal.

[0099] (4) Use heavy water to add fracturing fluid additives according to the field proportion for standby; measure the viscosity of the fracturing fluid, and prepare fluorine oil with the same viscosity as the field fracturing fluid for standby.

[0100] (5) Put core a into the core holder, 15MPa confining pressure, heat the system to reservoir temperature.

[0101] (6) Close the valve at the outlet end of the holder, inject heavy water fracturing fluid at a constant pressure of 10MPa through the plunger pump into 0.1 times Va, close the inlet valve for 20 minutes, remove the inlet valve pipeline, open the inlet valve to release, complete a round of short interval injection and production experiment.

[0102] (7) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, calculate the recovery rate of a round of short interval injection and production by the T2 signal total amount of a round of short interval injection and production and the T2 signal total amount of the saturated state according to formula (1), that is, the recovery rate Ra of oil washing + energy enhancement.

[0103] (8) Put core b into the core holder, 15MPa confining pressure, heat the system to reservoir temperature.

[0104] (9) Close the valve at the outlet end of the holder, inject heavy water fracturing fluid at a constant pressure of 10MPa through the plunger pump into 0.1 times Vb, close the inlet valve for 600 minutes, remove the inlet valve pipeline, open the inlet valve to release, complete a round of long interval injection and production experiment.

[0105] (10) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, calculate the recovery rate of a round of long interval injection and production by the T2 signal total amount of a round of long interval injection and production and the T2 signal total amount of the saturated state according to formula (1), that is, the recovery rate Rb of oil washing + imbibition + energy enhancement.

[0106] (11) Put core c into the core holder, 15MPa confining pressure, heat the system to reservoir temperature.

[0107] (12) Close the valve at the outlet end of the holder, inject fluorine oil at a constant pressure of 10MPa through the plunger pump into 0.1 times Vc, close the inlet valve for 600 minutes, remove the inlet valve pipeline, open the inlet valve to release, complete a round of long interval injection and production experiment (the long time interval is equal to the long time interval of core b).

[0108] (13) unload confining pressure, take out the core, the same parameter measurement core T2 signal, through a round of long interval T2 signal total amount and saturation state T2 signal total amount, the calculation of a round of long interval throughput recovery, namely the recovery of energy effect Rc.

[0109] (14) Rb-Ra gets imbibition displacement recovery (i.e. imbibition efficiency), Ra-Rc gets oil washing recovery (i.e. oil washing efficiency), Rc is the energy recovery.

[0110] (15) According to the analysis of the proportion of imbibition, oil washing and energy in the throughput recovery, the contribution degree of imbibition, oil washing and energy in the throughput process is quantitatively evaluated, and the specific results are shown in Table 1.

[0111] Example 3

[0112] (1) Drill three cylindrical cores with a length of 50mm and a diameter of 25mm at the same position of the artificial core, and place the cores in the middle container filled with reservoir crude oil to saturate the crude oil.

[0113] (2) After saturation, the cores are numbered as a, b and c, and the T2 relaxation spectrum is measured using the same measurement parameters.

[0114] (3) The T2 signal of 0.5ml, 1ml, 2ml, 3ml and 4ml volume of crude oil is measured using the same parameters as the core measurement, the relationship between the signal total amount and the crude oil volume is plotted, the relationship straight line between the crude oil volume and the signal total amount is obtained, the slope of the straight line is calculated, and the nuclear magnetic signal conversion coefficient under the current measurement parameter is obtained. The volume of crude oil in each core in the saturation state Va, Vb, Vc is calculated.

[0115] (4) Heavy water is added according to the field proportion to prepare fracturing fluid additives for standby; the viscosity of the fracturing fluid is measured, and fluorine oil with the same viscosity as the field fracturing fluid is prepared for standby.

[0116] (5) The core a is loaded into the core holder, the confining pressure is 20MPa, and the system is heated to the reservoir temperature.

[0117] (6) The outlet valve of the holder is closed, the heavy water fracturing fluid is injected into 0.1 times Va at a constant pressure of 15MPa through the plunger pump, the inlet valve is closed for 20 minutes, the inlet valve pipeline is removed, the inlet valve is opened to blow, and a round of short interval experiment is completed.

[0118] (7) unload confining pressure, take out the core, the same parameter measurement core T2 signal, through a round of long interval T2 signal total amount and saturation state T2 signal total amount, the calculation of a round of long interval throughput recovery, namely the recovery of energy effect Rc.

[0119] (8) Put core b into the core holder, confine pressure 20 Pa, heat the system to reservoir temperature.

[0120] (9) Close the outlet end valve of the holder, inject heavy water fracturing fluid into 0.1 times Vb at a constant pressure of 15 MPa through the plunger pump, close the inlet valve for 600 minutes, remove the inlet valve pipeline, open the inlet valve to blow out, and complete one round of long interval huff and puff experiment.

[0121] (10) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, pass the total amount of T2 signal of one round of long interval huff and puff through the total amount of T2 signal in the saturated state, and calculate the recovery rate of one round of long interval huff and puff according to formula (1), that is, the recovery rate of oil washing + imbibition + energy enhancement, Rb.

[0122] (11) Put core c into the core holder, confine pressure 20 MPa, heat the system to reservoir temperature.

[0123] (12) Close the outlet end valve of the holder, inject fluorine oil into 0.1 times Vc at a constant pressure of 15 MPa through the plunger pump, close the inlet valve for 600 minutes, remove the inlet valve pipeline, open the inlet valve to blow out, and complete one round of long interval huff and puff experiment (the long time interval is equal to the long time interval of core b).

[0124] (13) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, pass the total amount of T2 signal of one round of long interval huff and puff through the total amount of T2 signal in the saturated state, and calculate the recovery rate of one round of long interval huff and puff according to formula (1), that is, the recovery rate of energy enhancement, Rc.

[0125] (14) Rb-Ra gets the imbibition displacement recovery rate (i.e. imbibition efficiency), Ra-Rc gets the oil washing recovery rate (i.e. oil washing efficiency), and Rc is the energy enhancement recovery rate.

[0126] (15) According to the analysis of the proportion of imbibition, oil washing and energy enhancement in the huff and puff recovery rate, the contribution degree of imbibition, oil washing and energy enhancement in the huff and puff process is quantitatively evaluated, and the specific results are shown in Table 1.

[0127] Example 4

[0128] (1) Drill three cylindrical cores with a length of 50 mm and a diameter of 25 mm at the same position of the artificial core, and place the cores in the middle container filled with reservoir crude oil to saturate the crude oil.

[0129] (2) After saturation, number the cores as a, b and c, and measure the T2 relaxation spectrum with the same measurement parameters.

[0130] (3) Measure the T2 signal of 0.5ml, 1ml, 2ml, 3ml, 4ml volume of crude oil with the same parameters as core measurement, draw the relationship diagram of signal total amount and crude oil volume, get the relationship straight line of crude oil volume and signal total amount, calculate the slope of the straight line, get the conversion coefficient of crude oil volume and current measurement parameter under nuclear magnetic signal.

[0131] (4) Use heavy water to add fracturing fluid additives according to the field proportion for standby; measure the viscosity of the fracturing fluid, and prepare fluorine oil with the same viscosity as the field fracturing fluid for standby.

[0132] (5) Put core a into the core holder, confine pressure 25MPa, heat the system to reservoir temperature.

[0133] (6) Close the valve at the outlet end of the holder, inject heavy water fracturing fluid at a constant pressure of 20MPa through the plunger pump into 0.1 times Va, close the inlet valve for 20 minutes, remove the inlet valve pipeline, open the inlet valve to release, complete one round of short interval injection and production experiment.

[0134] (7) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, calculate the recovery rate of one round of short interval injection and production through the T2 signal total amount of one round of short interval injection and production and the T2 signal total amount of the saturated state according to formula (1), that is, the recovery rate Ra of oil washing + energy enhancement.

[0135] (8) Put core b into the core holder, confine pressure 25MPa, heat the system to reservoir temperature.

[0136] (9) Close the valve at the outlet end of the holder, inject heavy water fracturing fluid at a constant pressure of 20MPa through the plunger pump into 0.1 times Vb, close the inlet valve for 600 minutes, remove the inlet valve pipeline, open the inlet valve to release, complete one round of long interval injection and production experiment.

[0137] (10) Unload the confining pressure, take out the core, measure the T2 signal of the core with the same parameters, calculate the recovery rate of one round of long interval injection and production through the T2 signal total amount of one round of long interval injection and production and the T2 signal total amount of the saturated state according to formula (1), that is, the recovery rate Rb of oil washing + imbibition + energy enhancement.

[0138] (11) Put core c into the core holder, confine pressure 25MPa, heat the system to reservoir temperature.

[0139] (12) Close the valve at the outlet end of the holder, inject fluorine oil at a constant pressure of 20MPa through the plunger pump into 0.1 times Vc, close the inlet valve for 600 minutes, remove the inlet valve pipeline, open the inlet valve to release, complete one round of long interval injection and production experiment (the long time interval is equal to the long time interval of core b).

[0140] (13) unload confining pressure, take out the core, the same parameter measurement core T2 signal, through a round of long interval T2 signal total amount and saturation state T2 signal total amount, according to formula (1) calculation obtained a round of long interval throughput recovery, namely the recovery of energy effect Rc.

[0141] (14) Rb-Ra get imbibition displacement recovery (i.e. imbibition efficiency), Ra-Rc get oil washing recovery (i.e. oil washing efficiency), Rc is the energy recovery.

[0142] (15) according to the analysis of the proportion of imbibition, oil washing, energy in the throughput recovery, quantitative evaluation of imbibition, oil washing, energy contribution degree in the process of throughput, the specific results are shown in table 1.

[0143] Example 5

[0144] (1) in the same position of artificial core drilling three length 50mm diameter 25mm cylindrical core, the core is placed in the middle of the container with reservoir oil saturated oil.

[0145] (2) after saturation, the core is numbered as a, b, c, respectively, using the same measurement parameters to measure T2 relaxation spectrum.

[0146] (3) using the same parameters as the core measurement of 0.5ml, 1ml, 2ml, 3ml, 4ml volume of oil T2 signal, draw the signal total amount and oil volume relationship diagram, get the oil volume and signal total amount of linear relationship, calculate the slope of the straight line, get the oil volume and the current measurement parameter under the nuclear magnetic signal conversion coefficient. Calculate the oil volume Va, Vb, Vc in each core saturation state.

[0147] (4) using heavy water according to the field proportion to add fracturing fluid additives for standby; measurement of fracturing fluid viscosity, configuration and field fracturing fluid viscosity of fluorine oil for standby.

[0148] (5) the core a is loaded into the core holder, confining pressure 30MPa, the system is heated to reservoir temperature.

[0149] (6) the outlet valve of the holder is closed, and the heavy water fracturing fluid is injected into 0.1 times Va by constant pressure 25MPa through the plunger pump, the inlet valve is closed for 20 minutes, the inlet valve pipeline is unloaded, the inlet valve is opened, and the short interval experiment is completed.

[0150] (7) unload confining pressure, take out the core, the same parameter measurement core T2 signal, through a round of long interval T2 signal total amount and saturation state T2 signal total amount, according to formula (1) calculation obtained a round of long interval throughput recovery, namely the recovery of energy effect Rc.

[0151] (8) Put the core b into the core holder, the confining pressure is 30 Pa, and the system is heated to the reservoir temperature.

[0152] (9) The outlet end valve of the holder is closed, the heavy water fracturing fluid is injected into 0.1 times of Vb at a constant pressure of 25 MPa through the plunger pump, the inlet valve is closed for 600 minutes, the inlet valve pipeline is removed, the inlet valve is opened to blow out, and one round of long interval huffing experiment is completed.

[0153] (10) The confining pressure is unloaded, the core is taken out, the T2 signal of the core is measured with the same parameters, the total amount of the T2 signal in one round of long interval huffing is compared with the total amount of the T2 signal in the saturated state, the recovery rate of one round of long interval huffing is calculated according to formula (1), that is, the recovery rate of the oil washing + imbibition + energy enhancement effect Rb.

[0154] (11) Put the core c into the core holder, the confining pressure is 25 MPa, and the system is heated to the reservoir temperature.

[0155] (12) The outlet end valve of the holder is closed, the fluorine oil is injected into 0.1 times of Vc at a constant pressure of 20 MPa through the plunger pump, the inlet valve is closed for 600 minutes, the inlet valve pipeline is removed, the inlet valve is opened to blow out, and one round of long interval huffing experiment is completed (the long time interval is equal to the long time interval of the core b).

[0156] (13) The confining pressure is unloaded, the core is taken out, the T2 signal of the core is measured with the same parameters, the total amount of the T2 signal in one round of long interval huffing is compared with the total amount of the T2 signal in the saturated state, the recovery rate of one round of long interval huffing is calculated according to formula (1), that is, the recovery rate of the energy enhancement effect Rc.

[0157] (14) Rb-Ra is the imbibition displacement recovery rate (that is, the imbibition efficiency), Ra-Rc is the oil washing recovery rate (that is, the oil washing efficiency), and Rc is the energy enhancement recovery rate.

[0158] (15) According to the analysis of the proportion of imbibition, oil washing and energy enhancement in the huffing recovery rate, the contribution degree of imbibition, oil washing and energy enhancement in the huffing process is quantitatively evaluated, and the specific results are shown in Table 1.

[0159] Table 1

[0160]

[0161] As can be seen from the data in Table 1, the contribution degree of imbibition, oil washing and energy enhancement in the huffing process in Examples 1-5 is shown, and from the comparison between the data of Examples 1-5, it can be known that the difference of confining pressure and injection pressure affects the contribution degree of imbibition, oil washing and energy enhancement in the huffing process.

[0162] In the above examples, the fluid injected is only exemplarily listed as the fracturing fluid, and the method for quantitatively evaluating the contribution degrees of imbibition, oil displacement and energy increment in the huff and puff process of the embodiment of the present application is also applicable to the evaluation of the contribution degrees of imbibition, oil displacement and energy increment in the huff and puff process of other fluids (such as water, a mixture of water and surfactant and other displacement fluids) injected.

[0163] As shown in Figure 3 the system for quantitatively evaluating the contribution degrees of imbibition, oil displacement and energy increment in the huff and puff process according to the embodiment of the present application comprises:

[0164] a preparation module 1 for taking a plurality of parallel cores;

[0165] a combined measurement module 2 for randomly dividing the plurality of parallel cores into three groups, and performing a nuclear magnetic resonance-huff and puff combined test of a first time interval heavy water fluid, a nuclear magnetic resonance-huff and puff combined test of a second time interval heavy water fluid and a nuclear magnetic resonance-huff and puff combined test of a second time interval substitute liquid on the three groups of parallel cores respectively, wherein the test parameters in the nuclear magnetic resonance-huff and puff combined test of the first time interval heavy water fluid, the nuclear magnetic resonance-huff and puff combined test of the second time interval heavy water fluid and the nuclear magnetic resonance-huff and puff combined test of the second time interval substitute liquid are the same;

[0166] a calculation module 3 for obtaining the imbibition efficiency, oil displacement efficiency and energy increment recovery efficiency of the injected fluid in the huff and puff process based on a first recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the first time interval heavy water fluid, a second recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the second time interval heavy water fluid and a third recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the second time interval substitute liquid;

[0167] an evaluation module 4 for quantitatively evaluating the contribution degrees of imbibition, oil displacement and energy increment in the huff and puff process based on the imbibition efficiency, oil displacement efficiency and energy increment recovery efficiency in the huff and puff process.

[0168] In the embodiment of the present application, the calculation module 3 comprises an imbibition efficiency submodule, an oil displacement efficiency submodule and an energy increment recovery efficiency submodule;

[0169] the imbibition efficiency submodule is used for obtaining the imbibition efficiency of the injected fluid in the huff and puff process by subtracting the first recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the first time interval heavy water fluid from the second recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the second time interval heavy water fluid;

[0170] the oil displacement efficiency submodule is used for obtaining the oil displacement efficiency of the injected fluid in the huff and puff process by subtracting the third recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the second time interval substitute liquid from the first recovery efficiency determined by the nuclear magnetic resonance-huff and puff combined test of the first time interval heavy water fluid.

[0171] The energized recovery sub-module is configured to determine a third recovery determined by the second time interval instead of a liquid NMR-throughput test of the injected fluid in the process of the throughput as the energized recovery.

[0172] Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood that modifications can be made to the foregoing embodiments, or equivalents thereto, without departing from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for quantitatively evaluating the degree of contribution of imbibition, oil washing, and energy increase during a production process, characterized by, The method comprises the following steps: a plurality of parallel cores are taken; the plurality of parallel cores are randomly divided into three groups, and the three groups of parallel cores are respectively subjected to a first time interval heavy water fluid NMR-throughput combined test, a second time interval heavy water fluid NMR-throughput combined test, and a second time interval substitute liquid NMR-throughput combined test, wherein the test parameters in the first time interval heavy water fluid NMR-throughput combined test, the second time interval heavy water fluid NMR-throughput combined test, and the second time interval substitute liquid NMR-throughput combined test are the same; based on a first recovery rate determined by the first time interval heavy water fluid NMR-throughput combined test, a second recovery rate determined by the second time interval heavy water fluid NMR-throughput combined test, and a third recovery rate determined by the second time interval substitute liquid NMR-throughput combined test, the imbibition efficiency, the oil displacement efficiency, and the energy-increasing recovery rate of the injected fluid in the throughput process are obtained; based on the imbibition efficiency, the oil displacement efficiency, and the energy-increasing recovery rate in the throughput process, the contribution degrees of imbibition, oil displacement, and energy increase in the throughput process are quantitatively evaluated.

2. The method for quantitatively evaluating the degree of imbibition, oil-washing, and energy contribution in a production process according to claim 1, characterized by, The substitute liquid and the crude oil are independent phases from each other, and the volume of the substitute liquid after compression tends to be close to the original volume.

3. The method for quantitatively evaluating the degree of imbibition, oil-washing, and energy contribution in a production process according to claim 1, characterized by, The viscosity of the substitute liquid is the same as that of the heavy water fluid.

4. The method for quantitatively evaluating the degree of imbibition, oil-washing, and energy contribution in a production process according to claim 1, characterized by, The first time interval is smaller than the second time interval.

5. The method for quantitatively evaluating the degree of imbibition, oil-washing, and energy contribution in a production process according to claim 1, characterized in that, The first recovery rate determined by the first time interval heavy water fluid NMR-throughput combined test, the second recovery rate determined by the second time interval heavy water fluid NMR-throughput combined test, and the third recovery rate determined by the second time interval substitute liquid NMR-throughput combined test are used to obtain the imbibition efficiency, the oil displacement efficiency, and the energy-increasing recovery rate of the injected fluid in the throughput process, which comprises the following steps: the second recovery rate determined by the second time interval heavy water fluid NMR-throughput combined test is subtracted from the first recovery rate determined by the first time interval heavy water fluid NMR-throughput combined test to obtain the imbibition efficiency of the injected fluid in the throughput process; the first recovery rate determined by the first time interval heavy water fluid NMR-throughput combined test is subtracted from the third recovery rate determined by the second time interval substitute liquid NMR-throughput combined test to obtain the oil displacement efficiency of the injected fluid in the throughput process; the third recovery rate determined by the second time interval substitute liquid NMR-throughput combined test is determined as the energy-increasing recovery rate of the injected fluid in the throughput process.

6. The method for quantitatively evaluating the degree of imbibition, oil-washing, and energy contribution in a production process according to claim 1, characterized by, The specific operation of the NMR-throughput combined test comprises the following steps: the volume of the crude oil in the oil-saturated state of the core is obtained; the same test parameters as in the oil-saturated state of the core are set, and the NMR signal in the throughput state of the core is tested, wherein the throughput state of the core is the throughput state of the core under the heavy water fluid or the throughput state of the core under the substitute liquid.

7. The method for quantitatively evaluating the degree of imbibition, oil displacement, and energy increase contribution during the production process according to any one of claims 1 to 6, characterized in that, The quantitative evaluation of the contribution degrees of imbibition, oil displacement, and energy increase in the throughput process based on the imbibition efficiency, the oil displacement efficiency, and the energy-increasing recovery rate in the throughput process comprises the following steps: the ratio of the imbibition efficiency to the sum of the imbibition efficiency, the oil displacement efficiency, and the energy-increasing recovery rate is determined as the contribution rate of imbibition in the throughput process. The ratio of the oil washing efficiency to the imbibition efficiency, the oil washing efficiency and the energy increment recovery rate is determined as the contribution rate of oil washing in the huff and puff process; The ratio of the energy increment recovery rate to the imbibition efficiency, the oil washing efficiency and the energy increment recovery rate is determined as the contribution rate of energy increment in the huff and puff process; According to the contribution rate of imbibition, the contribution rate of oil washing and the contribution rate of energy increment in the huff and puff process, the contribution degrees of imbibition, oil washing and energy increment in the huff and puff process are evaluated.

8. The method for quantitatively evaluating the degree of imbibition, oil displacement, and energy increase contribution during the production process according to any one of claims 1 to 6, characterized by, The quantitative evaluation of the contribution degrees of imbibition, oil washing and energy increment in the huff and puff process based on the imbibition efficiency, the oil washing efficiency and the energy increment recovery rate in the huff and puff process comprises: According to the ratio among the imbibition efficiency, the oil washing efficiency and the energy increment recovery rate in the huff and puff process, the contribution degrees of imbibition, oil washing and energy increment in the huff and puff process are evaluated.

9. A system for quantitatively evaluating the degree of imbibition, oil washing, and energy increment contribution during the process of huff and puff, characterized in that, It comprises: The preparation module is used to take a plurality of parallel cores; The combined measurement module is used to randomly divide the plurality of parallel cores into three groups, and the three groups of parallel cores are respectively subjected to the first time interval heavy water fluid NMR-huff and puff combined test, the second time interval heavy water fluid NMR-huff and puff combined test and the second time interval substitute liquid NMR-huff and puff combined test, wherein the test parameters in the first time interval heavy water fluid NMR-huff and puff combined test, the second time interval heavy water fluid NMR-huff and puff combined test and the second time interval substitute liquid NMR-huff and puff combined test are the same; The calculation module is used to obtain the imbibition efficiency, the oil washing efficiency and the energy increment recovery rate of the injected fluid in the huff and puff process based on the first recovery rate determined by the first time interval heavy water fluid NMR-huff and puff combined test, the second recovery rate determined by the second time interval heavy water fluid NMR-huff and puff combined test and the third recovery rate determined by the second time interval substitute liquid NMR-huff and puff combined test; The evaluation module is used to quantitatively evaluate the contribution degrees of imbibition, oil washing and energy increment in the huff and puff process based on the imbibition efficiency, the oil washing efficiency and the energy increment recovery rate in the huff and puff process.

10. The system for quantitatively evaluating the degree of imbibition, oil-washing, and energy contribution during a production process according to claim 9, wherein The calculation module comprises an imbibition efficiency submodule, an oil washing efficiency submodule and an energy increment recovery rate submodule; The imbibition efficiency submodule is used to obtain the imbibition efficiency of the injected fluid in the huff and puff process by subtracting the first recovery rate determined by the first time interval heavy water fluid NMR-huff and puff combined test from the second recovery rate determined by the second time interval heavy water fluid NMR-huff and puff combined test; The oil washing efficiency submodule is used to obtain the oil washing efficiency of the injected fluid in the huff and puff process by subtracting the third recovery rate determined by the second time interval substitute liquid NMR-huff and puff combined test from the first recovery rate determined by the first time interval heavy water fluid NMR-huff and puff combined test; The energy increment recovery rate submodule is used to determine the third recovery rate determined by the second time interval substitute liquid NMR-huff and puff combined test as the energy increment recovery rate of the injected fluid in the huff and puff process.

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