Method and equipment for simulating tertiary oil recovery after water drive of strong heterogeneity oil reservoir

Abstract

The invention provides a method and equipment for simulating tertiary oil recovery after strong heterogeneity oil reservoir water flooding, and the method comprises the steps: determining corresponding stratum particle size distribution information according to drilling and logging data of a target reservoir, so as to obtain a corresponding initial core sample; performing displacement saturation treatment on the first rock core sample by adopting a standard formation water solution and formation crude oil to obtain a second rock core sample; putting the second rock core sample and a standard formation water solution into a target displacement device, establishing a target displacement environment, and controlling the target displacement device to monitor the second rock core sample in real time according to the target displacement environment; according to the target displacement device, obtaining a corresponding initial picture, and adopting multiple displacement phases to perform multiple displacement treatment on the second rock core sample; and when each displacement treatment is completed, the corresponding target picture is obtained according to the target displacement device, and the target oil extraction data is determined according to the initial picture and the target picture, so that the technical effect of improving the oil extraction efficiency of the heterogeneous oil reservoir is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas field development, and in particular to a method and equipment for simulating tertiary oil recovery after water flooding in a highly heterogeneous oil reservoir. Background Art

[0002] With the continuous advancement of science and technology, oil and gas field exploration and development technology has become increasingly sophisticated. In the secondary and tertiary oil recovery processes in the field of oil and gas field development, vertical reservoir heterogeneity is a common problem, which has a significant impact on the water injection development effect of the oil field. Due to the vertical heterogeneity of the reservoir, the injected water tends to flow to the high permeability layer, resulting in the ineffective development of oil and gas resources in the low permeability layer. In view of this, in order to solve this key problem that restricts the efficient development of oil fields, the tertiary oil recovery method after water flooding in strongly heterogeneous reservoirs has become a research direction with application prospects.

[0003] In the prior art, the tertiary oil recovery method after water flooding in highly heterogeneous reservoirs is mainly carried out through indoor displacement experiments. Under the condition of simulating a single reservoir unit, operators inject different profile control agents into it to change the permeability distribution of the reservoir, thereby improving the oil and gas recovery rate of the permeability layer.

[0004] In the prior art, there is a lack of intuitive observation methods in the overall displacement process, and some experimental devices are complicated in design and rely on manual operation. The displacement process consumes a lot of time and manpower costs. For heterogeneous reservoirs, there is a technical problem of low oil recovery efficiency in heterogeneous reservoirs. Summary of the invention

[0005] The embodiment of the present application provides a method and equipment for simulating tertiary oil recovery after water flooding in a highly heterogeneous oil reservoir, so as to achieve the technical effect of improving the oil recovery efficiency of the heterogeneous oil reservoir.

[0006] In a first aspect, the present application provides a method for simulating tertiary oil recovery after water flooding in a highly heterogeneous reservoir, comprising:

[0007] According to the drilling and logging data of the target reservoir, the corresponding formation grain size distribution information is determined to obtain the corresponding initial core sample, wherein the initial core sample is a heterogeneous core sample prepared after simulating the formation grain size distribution;

[0008] Using a standard formation water solution and formation crude oil, the first core sample is subjected to a displacement saturation treatment to obtain a second core sample, wherein the first core sample is a core sample obtained by drying the initial core sample, and the second core sample is a core sample obtained by displacing and saturating the first core sample;

[0009] placing the second core sample and the standard formation water solution into a target displacement device to establish a target displacement environment, and controlling the target displacement device to monitor the second core sample in real time according to the target displacement environment;

[0010] According to the target displacement device, a corresponding initial image is obtained, and multiple displacement phases are used to perform multiple displacement treatments on the second core sample, wherein the displacement phase includes a chemical displacement agent, a standard formation water solution and a target gas, the displacement treatment includes a chemical displacement treatment, a water displacement treatment and a gas displacement treatment, the chemical displacement agent includes a chemical plugging agent or a cross-linking agent, and the initial image is used to indicate the nuclear magnetic resonance imaging image of the second core sample before the displacement treatment;

[0011] When each displacement treatment is completed, the corresponding target image is obtained according to the target displacement device, and the target oil production data is determined according to the initial image and the target image, wherein the target oil production data includes the injection end pressure change rate with the seepage distance and the recovery rate. The target image is used to indicate the nuclear magnetic resonance imaging image of the second core sample after each displacement treatment is completed, and each displacement treatment corresponds to a target image.

[0012] Optionally, a standard formation water solution and formation crude oil are used to perform displacement saturation treatment on the first core sample to obtain a second core sample, including:

[0013] subjecting the experimental beaker with the initial core sample to vacuum treatment, and adding simulated formation water solution into the vacuum treated experimental beaker;

[0014] After confirming that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on the surface of the initial core sample, the initial core sample is subjected to water flooding treatment using a standard formation water solution to obtain a third core sample after treatment;

[0015] Using formation crude oil, the third core sample is subjected to displacement saturation treatment to obtain a fourth core sample after treatment;

[0016] After placing the fourth core sample into the formation crude oil and pressurizing it to a target pressure, the fourth core sample is subjected to a static treatment;

[0017] After determining that the static time of the fourth core sample reaches the first threshold, the corresponding second core sample is obtained.

[0018] Optionally, the target displacement device comprises:

[0019] a core holder for fixing and holding the second core sample;

[0020] a displacement pump for controlling the flow rate of the displacement phase and the rate at which the second core sample is injected;

[0021] An intermediate container for storing and supplying the displacement phase required for the displacement treatment;

[0022] Dual-cylinder constant speed and constant pressure displacement system, used to control and adjust the working state of the displacement pump;

[0023] Axial confining pressure pump, used to simulate the pressure of the formation in the vertical direction;

[0024] Radial confining pressure pump, used to simulate the horizontal pressure of the formation;

[0025] A heated circulation pump to set and maintain the internal temperature of the core holder;

[0026] Needle valves at the front and rear ends of the core holder are used to control the injection and discharge of the displacement phase at the front and rear ends of the core holder;

[0027] A magnet, used to generate a stable magnetic field environment;

[0028] The data acquisition imaging system is used to monitor and collect nuclear magnetic imaging images in real time during the displacement process according to the magnetic field environment, and determine the signal quantity corresponding to the nuclear magnetic imaging images;

[0029] Back pressure pump, used to set the outlet pressure value required for displacement treatment, and to adjust and control the back pressure during displacement treatment;

[0030] The measuring cylinder is used to receive the produced liquid generated when the pressure of the back pressure pump valve is released when it is determined that the pressure corresponding to the back pressure pump reaches the second threshold.

[0031] Optionally, placing a second core sample and a standard formation water solution into a target displacement device to establish a target displacement environment includes:

[0032] According to the target displacement device, a second core sample is fixed to the core holder, and a standard formation water solution is placed in an intermediate container;

[0033] According to the dual-cylinder constant speed and constant pressure displacement system, the pressures of the axial confining pressure pump and the radial confining pressure pump are set to target pressure values, and the heating circulation pump is set to a third threshold value;

[0034] After determining that the temperature inside the core holder is constant at the third threshold, controlling the needle valves at the front and rear ends of the core holder to close the valves;

[0035] After determining that the upper end pressure of the core holder reaches the fourth threshold, the front and rear end needle valves of the core holder are controlled to open the valves, and the outlet pressure value of the back pressure pump is set to the fifth threshold to establish the target displacement environment.

[0036] Optionally, the second core sample is subjected to multiple flooding treatments using multiple flooding phases, including:

[0037] According to the dual-cylinder constant speed and constant pressure displacement system, the displacement pump flow rate is set to a target flow rate, and according to the target flow rate, a standard formation water solution having a target injection volume is injected into the second core sample to perform water flooding treatment;

[0038] After determining that the displacement pump displacement volume reaches the sixth threshold, replacing the standard formation water solution with a chemical displacement agent, and injecting the chemical displacement agent with a target injection volume into the second core sample to perform chemical flooding treatment;

[0039] After confirming that the chemical flooding treatment is completed, the chemical flooding agent is replaced with a standard formation water solution, and the standard formation water solution having a target injection volume is injected into the second core sample, and the second core sample is subjected to water flooding treatment;

[0040] After it is determined that the water flooding treatment is completed, the standard formation water solution is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform the gas flooding treatment.

[0041] Optionally, according to the second fragment sequence, the target injection amount is obtained by:

[0042] Determine a corresponding initial weight based on the initial core sample, and determine a corresponding target weight and pore volume based on the second core sample;

[0043] According to the initial weight and the target weight, the corresponding weight difference is determined;

[0044] The corresponding pore volume is obtained according to the weight difference and the density of the standard formation water solution, and the corresponding target injection volume is determined according to the pore volume.

[0045] Optionally, after injecting a target gas having a target injection volume into the second core sample for gas drive treatment, the method further includes:

[0046] The second core sample is monitored according to the target displacement device;

[0047] After determining that gas channeling occurs in the second core sample, injecting a chemical plugging agent having a target injection amount into the second core sample for plugging;

[0048] After confirming that there is no gas channeling in the second core sample, the chemical plugging agent is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform gas drive treatment.

[0049] Optionally, target oil production data is determined based on the initial image and the target image, including:

[0050] According to the initial image and the corresponding target image after water flooding treatment, the injection end pressure curve corresponding to the second core sample is obtained, wherein the injection end pressure curve is used to indicate the penetration distance of the displacement phase in the second core sample during the displacement treatment process and the variation trend of the injection end pressure with time or the injection amount of the displacement phase;

[0051] According to the injection end pressure curve, determine the injection end pressure change rate of the second core sample with the seepage distance;

[0052] According to the data acquisition imaging system, an initial signal amount corresponding to the initial image is obtained, and according to each target image, a target signal amount corresponding to each target image is obtained;

[0053] The recovery factor of the second core sample is determined based on the initial signal amount and the target signal amount.

[0054] In a second aspect, the present application provides a tertiary oil recovery device for simulating water flooding of a strongly heterogeneous oil reservoir, comprising:

[0055] The first acquisition module is used to determine the corresponding formation grain size distribution information according to the drilling and logging data of the target reservoir to obtain the corresponding initial core sample, wherein the initial core sample is a heterogeneous core sample prepared after simulating the formation grain size distribution;

[0056] A second acquisition module is used to perform a displacement saturation treatment on the first core sample using a standard formation water solution and formation crude oil to obtain a second core sample, wherein the first core sample is a core sample obtained by drying the initial core sample, and the second core sample is a core sample obtained by performing a displacement saturation treatment on the first core sample;

[0057] The first processing module is used to place the second core sample and the standard formation water solution into the target displacement device to establish a target displacement environment, and control the target displacement device to monitor the second core sample in real time according to the target displacement environment;

[0058] The second processing module is used to obtain the corresponding initial image according to the target displacement device, and use multiple displacement phases to perform multiple displacement treatments on the second core sample, wherein the displacement phase includes a chemical displacement agent, a standard formation water solution and a target gas, the displacement treatment includes a chemical displacement treatment, a water displacement treatment and a gas displacement treatment, the chemical displacement agent includes a chemical plugging agent or a cross-linking agent, and the initial image is used to indicate the nuclear magnetic resonance imaging image of the second core sample before the displacement treatment;

[0059] The third acquisition module is used to obtain the corresponding target image according to the target displacement device when each displacement treatment is completed, and determine the target oil production data according to the initial image and the target image, wherein the target oil production data includes the injection end pressure change rate with the seepage distance and the recovery rate. The target image is used to indicate the nuclear magnetic resonance imaging image of the second core sample after each displacement treatment is completed, and each displacement treatment corresponds to a target image.

[0060] Optionally, the second acquisition module is further used for:

[0061] subjecting the experimental beaker with the initial core sample to vacuum treatment, and adding simulated formation water solution into the vacuum treated experimental beaker;

[0062] After confirming that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on the surface of the initial core sample, the initial core sample is subjected to water flooding treatment using a standard formation water solution to obtain a third core sample after treatment;

[0063] Using formation crude oil, the third core sample is subjected to displacement saturation treatment to obtain a fourth core sample after treatment;

[0064] After placing the fourth core sample into the formation crude oil and pressurizing it to a target pressure, the fourth core sample is subjected to a static treatment;

[0065] After determining that the static time of the fourth core sample reaches the first threshold, the corresponding second core sample is obtained.

[0066] Optionally, the first processing module is also used for a target displacement device, comprising:

[0067] a core holder for fixing and holding the second core sample;

[0068] a displacement pump for controlling the flow rate of the displacement phase and the rate at which the second core sample is injected;

[0069] An intermediate container for storing and supplying the displacement phase required for the displacement treatment;

[0070] Dual-cylinder constant speed and constant pressure displacement system, used to control and adjust the working state of the displacement pump;

[0071] Axial confining pressure pump, used to simulate the pressure of the formation in the vertical direction;

[0072] Radial confining pressure pump, used to simulate the horizontal pressure of the formation;

[0073] A heated circulation pump to set and maintain the internal temperature of the core holder;

[0074] Needle valves at the front and rear ends of the core holder are used to control the injection and discharge of the displacement phase at the front and rear ends of the core holder;

[0075] A magnet, used to generate a stable magnetic field environment;

[0076] The data acquisition imaging system is used to monitor and collect nuclear magnetic imaging images in real time during the displacement process according to the magnetic field environment, and determine the signal quantity corresponding to the nuclear magnetic imaging images;

[0077] Back pressure pump, used to set the outlet pressure value required for displacement treatment, and to adjust and control the back pressure during displacement treatment;

[0078] The measuring cylinder is used to receive the produced liquid generated when the pressure of the back pressure pump valve is released when it is determined that the pressure corresponding to the back pressure pump reaches the second threshold.

[0079] Optionally, the first processing module is further used for:

[0080] According to the target displacement device, a second core sample is fixed to the core holder, and a standard formation water solution is placed in an intermediate container;

[0081] According to the dual-cylinder constant speed and constant pressure displacement system, the pressures of the axial confining pressure pump and the radial confining pressure pump are set to target pressure values, and the heating circulation pump is set to a third threshold value;

[0082] After determining that the temperature inside the core holder is constant at the third threshold, controlling the needle valves at the front and rear ends of the core holder to close the valves;

[0083] After determining that the upper end pressure of the core holder reaches the fourth threshold, the front and rear end needle valves of the core holder are controlled to open the valves, and the outlet pressure value of the back pressure pump is set to the fifth threshold to establish the target displacement environment.

[0084] Optionally, the second processing module is further used for:

[0085] According to the dual-cylinder constant speed and constant pressure displacement system, the displacement pump flow rate is set to a target flow rate, and according to the target flow rate, a standard formation water solution having a target injection volume is injected into the second core sample to perform water flooding treatment;

[0086] After determining that the displacement pump displacement volume reaches the sixth threshold, replacing the standard formation water solution with a chemical displacement agent, and injecting the chemical displacement agent with a target injection volume into the second core sample to perform chemical flooding treatment;

[0087] After confirming that the chemical flooding treatment is completed, the chemical flooding agent is replaced with a standard formation water solution, and the standard formation water solution having a target injection volume is injected into the second core sample, and the second core sample is subjected to water flooding treatment;

[0088] After it is determined that the water flooding treatment is completed, the standard formation water solution is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform the gas flooding treatment.

[0089] Optionally, the second processing module is further used for:

[0090] Determine a corresponding initial weight based on the initial core sample, and determine a corresponding target weight and pore volume based on the second core sample;

[0091] According to the initial weight and the target weight, the corresponding weight difference is determined;

[0092] The corresponding pore volume is obtained according to the weight difference and the density of the standard formation water solution, and the corresponding target injection volume is determined according to the pore volume.

[0093] Optionally, the second processing module is further used for:

[0094] The second core sample is monitored according to the target displacement device;

[0095] After determining that gas channeling occurs in the second core sample, injecting a chemical plugging agent having a target injection amount into the second core sample for plugging;

[0096] After confirming that there is no gas channeling in the second core sample, the chemical plugging agent is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform gas drive treatment.

[0097] Optionally, the third acquisition module is further used for:

[0098] According to the initial image and the corresponding target image after water flooding treatment, the injection end pressure curve corresponding to the second core sample is obtained, wherein the injection end pressure curve is used to indicate the penetration distance of the displacement phase in the second core sample during the displacement treatment process and the variation trend of the injection end pressure with time or the injection amount of the displacement phase;

[0099] According to the injection end pressure curve, determine the injection end pressure change rate of the second core sample with the seepage distance;

[0100] According to the data acquisition imaging system, an initial signal amount corresponding to the initial image is obtained, and according to each target image, a target signal amount corresponding to each target image is obtained;

[0101] The recovery factor of the second core sample is determined based on the initial signal amount and the target signal amount.

[0102] In a third aspect, the present application provides a tertiary oil recovery device for simulating water flooding of a strongly heterogeneous oil reservoir, comprising:

[0103] Processor and memory;

[0104] Memory stores computer-executable instructions;

[0105] The processor executes the computer-executable instructions stored in the memory, so that the processor executes various possible implementations of the first aspect as described above.

[0106] In a fourth aspect, the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement various possible implementation methods as in the first aspect.

[0107] In a fifth aspect, the present application provides a computer program product, which, when executed by a processor, is used to implement various possible implementations as in the first aspect.

[0108] The present application provides a method and device for simulating tertiary oil recovery after water flooding of a strongly heterogeneous oil reservoir. The method comprises the following steps: determining the corresponding formation particle size distribution information according to the drilling and logging data of the target reservoir to obtain the corresponding initial core sample; performing a displacement saturation treatment on the first core sample using a standard formation water solution and formation crude oil to obtain a second core sample; placing the second core sample and the standard formation water solution into a target displacement device to establish a target displacement environment, and controlling the target displacement device to monitor the second core sample in real time according to the target displacement environment; obtaining the corresponding initial image according to the target displacement device, and performing multiple displacement treatments on the second core sample using multiple displacement phases; obtaining the corresponding target image according to the target displacement device when each displacement treatment is completed, and performing a multiple displacement treatment on the second core sample according to the initial image and the displacement phase; The target picture is obtained to determine the target oil production data, so that multiple displacement treatments can be flexibly adopted by the target displacement device relative to the second core sample for multiple displacement treatments, which not only significantly improves the convenience and rapidity of the overall displacement treatment process, but also effectively reduces the cost consumption in terms of manpower, material resources and time. In addition, with the help of the target displacement device, while real-time monitoring of the changes of the second core sample during the displacement experiment is carried out, the corresponding initial picture and target picture are generated, which provides a more intuitive observation method for the overall displacement treatment process, and through the analysis of these initial pictures and target pictures, the corresponding target oil production data are obtained, which ensures the reliability and accuracy of the data, solves the technical problem of low oil production efficiency in heterogeneous reservoirs, and achieves the technical effect of improving the oil production efficiency in heterogeneous reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0110] Figure 1 The process of simulating the tertiary oil recovery method after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application Figure 1 ;

[0111] Figure 2A schematic diagram of the structure of the initial core sample provided in the embodiment of the present application;

[0112] Figure 3 The process of tertiary oil recovery after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application is as follows Figure 2 ;

[0113] Figure 4 A schematic diagram of the structure of a target displacement device provided in an embodiment of the present application;

[0114] Figure 5 The process of tertiary oil recovery after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application is as follows Figure 3 ;

[0115] Figure 6 The process of tertiary oil recovery after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application is as follows Figure 4 ;

[0116] Figure 7 The process of simulating the tertiary oil recovery method after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application Figure 5 ;

[0117] Figure 8 A schematic diagram of a target image provided in an embodiment of the present application;

[0118] Fig. 9 A schematic diagram of the structure of a tertiary oil recovery device after water flooding in a simulated strongly heterogeneous reservoir provided in an embodiment of the present application;

[0119] Fig.10 A hardware structure diagram of a tertiary oil recovery device for simulating water flooding in a highly heterogeneous reservoir provided in an embodiment of the present application.

[0120] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0121] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0122] In the prior art, there is a lack of intuitive observation methods in the overall displacement process, and some experimental devices are complicated in design. The displacement process consumes a lot of time and manpower costs. For heterogeneous reservoirs, there is a technical problem of low oil recovery efficiency in heterogeneous reservoirs.

[0123] In response to the above problems, the present application provides a method and equipment for simulating tertiary oil recovery after water flooding in a strongly heterogeneous oil reservoir. Through a target displacement device, a variety of relatively heterogeneous core samples are flexibly used for multiple displacement treatments, which not only significantly improves the convenience and speed of the overall displacement treatment process, but also effectively reduces the cost consumption in terms of manpower, material resources and time. In addition, with the help of the target displacement device, while real-time monitoring of the changes in the core samples during the displacement experiment, the corresponding initial images before displacement and target images after displacement are generated, which provides a more intuitive means of observation for the overall displacement treatment process. By analyzing these initial images and target images, the injection end pressure change rate and recovery rate corresponding to the core sample with the seepage distance are obtained, ensuring the reliability and accuracy of the data, solving the technical problem of low oil recovery efficiency in heterogeneous reservoirs, and achieving the technical effect of improving the oil recovery efficiency in heterogeneous reservoirs.

[0124] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0125] Figure 1 The process of simulating the tertiary oil recovery method after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application Figure 1 .like Figure 1 As shown, the tertiary oil recovery method after water flooding of a simulated strongly heterogeneous reservoir provided in the embodiment of the present application includes:

[0126] S101, determining corresponding formation grain size distribution information according to drilling and logging data of the target reservoir to obtain a corresponding initial core sample;

[0127] In this embodiment, the initial core sample is a heterogeneous core sample prepared after simulating the formation particle size distribution. The target reservoir includes multiple different reservoirs, and the drilling and logging data include but are not limited to layer porosity, permeability, oil and gas saturation, lithology, particle size, and sorting.

[0128] According to the drilling and logging data of multiple different reservoirs in the target reservoir, the corresponding formation grain size distribution information is determined, and according to the formation grain size distribution information, the corresponding initial core sample is prepared.

[0129] Specifically, Figure 2The structural schematic diagram of the initial core sample provided in the embodiment of the present application relies on the drilling and logging data obtained during the drilling and logging process to obtain the stratigraphic grain size distribution information of different reservoirs corresponding to the target reservoir, and according to the stratigraphic grain size distribution information, sand and gravel are put into the core preparation mold in stages and layers, and pressed into the core by a hydraulic press. Figure 2 Heterogeneous core sample shown.

[0130] S102, using a standard formation water solution and formation crude oil to perform a displacement saturation treatment on the first core sample to obtain a second core sample;

[0131] In this embodiment, the first core sample is a core sample obtained by drying the initial core sample, and the second core sample is a core sample obtained by performing a displacement saturation treatment on the first core sample.

[0132] After the initial core sample is prepared, the initial core sample is dried to obtain a first processed core sample, and the configured standard formation water solution and formation crude oil are selected to perform displacement saturation treatment on the first core sample to obtain a second processed core sample.

[0133] Specifically, according to SY / T5336 standard, the initial core sample is kept at a temperature not higher than 60°C, the relative humidity is controlled to be maintained at about 40% to 50%, and the drying is continued for 48 hours. After 48 hours, it is measured every 8 hours, and the difference between the two masses is controlled to be less than 10 mg. The dried core sample is placed on an analytical balance to measure the weight. After determining that the weight of the core sample is constant, the dried core sample is determined as the first core sample. The configured standard formation water solution and formation crude oil are selected, and the first core sample is subjected to displacement saturation treatment to obtain the treated second core sample.

[0134] S103, placing the second core sample and the standard formation water solution into a target displacement device, establishing a target displacement environment, and controlling the target displacement device to monitor the second core sample in real time according to the target displacement environment;

[0135] The second core sample and the standard formation water solution are placed in the target displacement device respectively, and the target displacement device is adjusted internally to establish a target displacement environment suitable for displacement treatment. After it is determined that the target displacement environment has been established, the target displacement device is started and controlled to facilitate real-time detection of the second core sample before and after the displacement treatment.

[0136] S104, acquiring a corresponding initial image according to a target displacement device, and performing multiple displacement processes on the second core sample using multiple displacement phases;

[0137] In this embodiment, the displacement phase includes a chemical displacement agent, a standard formation water solution and a target gas, the displacement treatment includes a chemical displacement treatment, a water displacement treatment and a gas displacement treatment, the chemical displacement agent includes a chemical plugging agent or a cross-linking agent, and the initial image is used to indicate the nuclear magnetic resonance imaging image of the second core sample before the displacement treatment.

[0138] Before the displacement treatment begins, the target displacement device is controlled to obtain an initial image corresponding to the second core sample, and the second core sample is subjected to multiple displacement treatments using a chemical displacement agent, a standard formation water solution, and a target gas, respectively.

[0139] S105, when each displacement process is completed, a corresponding target image is obtained according to the target displacement device, and target oil production data is determined according to the initial image and the target image;

[0140] In this embodiment, the target oil production data include the injection end pressure change rate with the seepage distance and the recovery rate. The target image is used to indicate the nuclear magnetic resonance imaging image of the second core sample after each displacement treatment is completed. Each displacement treatment corresponds to a target image.

[0141] During the process of monitoring the displacement treatment, the target displacement device will generate corresponding nuclear magnetic resonance imaging images in real time. When each displacement phase completes a displacement treatment, the processed target image is obtained based on these nuclear magnetic resonance imaging images, and the initial image is combined with the target image to determine the changes before and after the second core sample and analyze them to determine the target oil production data of the second core sample after the displacement treatment.

[0142] The present application provides a method for simulating tertiary oil recovery after water flooding in a highly heterogeneous reservoir. The method comprises the following steps: determining the corresponding formation particle size distribution information according to the drilling and logging data of the target reservoir to obtain the corresponding initial core sample; using a standard formation water solution and formation crude oil to perform displacement saturation treatment on the first core sample to obtain a second core sample; placing the second core sample and the standard formation water solution into a target displacement device to establish a target displacement environment, and controlling the target displacement device to monitor the second core sample in real time according to the target displacement environment; obtaining the corresponding initial image according to the target displacement device, and using The second core sample is subjected to multiple displacement phases and multiple displacement treatments; when each displacement treatment is completed, the corresponding target image is obtained according to the target displacement device, and the target oil production data is determined according to the initial image and the target image, so as to prepare the heterogeneous initial core sample separately according to the drilling and logging data of the target reservoir. The sample fully reflects the heterogeneity of the reservoir between the vertical layers and the heterogeneity of the sedimentary particle size. The representativeness and accuracy of the core sample are further enhanced by the refined formation grain size distribution information. At the same time, the standard formation water solution is used to determine the target oil production data. After the first core sample is saturated with liquid and formation crude oil, the second core sample obtained is placed in a target displacement device, which has non-destructive monitoring capabilities and can monitor and evaluate the changes of the second core sample in real time and accurately during the displacement process; in addition, the target displacement device can not only obtain the initial picture at the beginning of the experiment, but also flexibly adopt multiple displacements to carry out multiple displacement treatments relative to the second core sample, which significantly improves the convenience and rapidity of the overall displacement treatment process while effectively reducing the cost consumption in manpower, material resources and time; with the help of the target displacement device, the corresponding initial picture and target picture are generated while the changes of the second core sample in the displacement experiment are monitored in real time, which provides a more intuitive observation method for the overall displacement treatment process, and through the analysis of these initial pictures and target pictures, the corresponding target oil production data are obtained, ensuring the reliability and accuracy of the data, solving the technical problem of low oil production efficiency in heterogeneous reservoirs, and achieving the technical effect of improving the oil production efficiency of heterogeneous reservoirs.

[0143] Figure 3 The process of tertiary oil recovery after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application is as follows Figure 2 .like Figure 3 As shown, this embodiment provides a supplementary description of the process of obtaining the second core sample based on the above embodiment, including:

[0144] S301, subjecting the experimental beaker with the initial core sample to vacuum treatment, and adding simulated formation water solution into the vacuum treated experimental beaker;

[0145] The experimental beaker with the initial core sample is placed in a vacuum pump and subjected to vacuum treatment by the vacuum pump. After the vacuum treatment is completed, a simulated formation water solution is added into the experimental beaker.

[0146] Specifically, the experimental beaker with the initial core sample is placed in a vacuum pump, and the vacuum pump is continuously evacuated for 12 hours. After it is determined that the vacuum treatment is completed, the simulated formation water solution is added to the experimental beaker.

[0147] S302, after determining that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on the surface of the initial core sample, use a standard formation water solution to perform water flooding treatment on the initial core sample to obtain a third core sample after treatment;

[0148] After confirming that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on its surface, the initial core sample is continuously subjected to displacement treatment using a standard formation water solution to obtain a third core sample after treatment.

[0149] Specifically, after confirming that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on its surface, the initial core sample is placed in a corresponding displacement device to displace a saturated 5PV standard formation water solution to obtain a corresponding third core sample.

[0150] S303, using formation crude oil to perform displacement saturation treatment on the third core sample to obtain a treated fourth core sample;

[0151] The third core sample is continuously subjected to displacement and saturation treatment using formation crude oil, and the core sample after the treatment is determined as the fourth core sample.

[0152] S304, after placing the fourth core sample into the formation crude oil and pressurizing it to the target pressure, the fourth core sample is placed in a static state, and after determining that the static state time of the fourth core sample reaches a first threshold, a corresponding second core sample is obtained.

[0153] The fourth core sample is placed in formation crude oil, pressurized to a target pressure, and then left to stand. After determining that the standing time reaches a first threshold, the corresponding second core sample is obtained.

[0154] Specifically, for the fourth core sample, it is placed in formation crude oil, pressurized to 20 MPa and left to stand for 12 hours. After the standing time is completed, the core sample is taken out and determined as the second core sample.

[0155] The present application provides a method for simulating tertiary oil recovery after water flooding of a strongly heterogeneous oil reservoir. Before the displacement treatment, the heterogeneous core sample is subjected to vacuum, displacement saturation, pressurization and static treatment in sequence to obtain a simulated experimental sample that is the same as the actual core sample. While ensuring the authenticity and reliability of the target adopted data after the subsequent displacement treatment, the complexity of sample preparation is reduced, the cost consumption in terms of manpower, material resources and time is effectively reduced, and the technical problem of low oil recovery efficiency in heterogeneous oil reservoirs is solved, thereby achieving the technical effect of improving the oil recovery efficiency in heterogeneous oil reservoirs.

[0156] Figure 4 A schematic diagram of the structure of the target displacement device provided in the embodiment of the present application is shown in FIG. Figure 4 As shown in the figure, the target displacement device includes: 1. a dual-cylinder constant speed and constant pressure displacement system; 2. an axial confining pressure pump; 3. a pressure sensor; 4. a radial confining pressure pump; 5. a magnet; 6. a data acquisition imaging system; 7. a core holder; 8. a rock sample; 9. needle valves at the front and rear ends of the core holder; 10. an intermediate container; 11. a displacement pump; 12. fluorocarbon oil; 13. a heating circulation pump; 14. a back pressure pump; 15. a measuring cylinder; 16. a back pressure valve; wherein the core holder is used to fix and clamp the second core sample; the displacement pump is used to control the flow rate of the displacement phase and the speed of injecting the second core sample; the intermediate container is used to store and supply the displacement phase required for the displacement treatment; the dual-cylinder constant speed and constant pressure displacement system is used to control and adjust the working state of the displacement pump; the axial confining pressure ... A pressure pump is used to simulate the pressure of the formation in the longitudinal direction; a radial confining pressure pump is used to simulate the pressure of the formation in the horizontal direction; a heating circulation pump is used to set and maintain the internal temperature of the core holder; needle valves at the front and rear ends of the core holder are used to control the injection and discharge of the displacement phase at the front and rear ends of the core holder; a magnet is used to generate a stable magnetic field environment; a data acquisition imaging system is used to monitor and collect nuclear magnetic imaging images in the displacement process in real time according to the magnetic field environment, and determine the signal quantity corresponding to the nuclear magnetic imaging images; a back pressure pump is used to set the outlet pressure value required for the displacement process, and adjust and control the back pressure in the displacement process; a measuring cylinder is used to receive the produced fluid generated by the pressure release of the back pressure pump valve when it is determined that the pressure corresponding to the back pressure pump reaches the second threshold.

[0157] Figure 5 The process of tertiary oil recovery after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application is as follows Figure 3 .like Figure 5 As shown, this embodiment provides a supplementary explanation of the process of establishing the target displacement environment based on the above embodiment, including:

[0158] S501, according to the target displacement device, fix the second core sample to the core holder, and put the standard formation water solution into the intermediate container;

[0159] In this embodiment, the first marking character is used to indicate that the pre-training data is retained.

[0160] Place the saturated core sample in the core holder, tighten the plug on the right, fill in the plug on the left, and put the standard formation water solution required for displacement treatment in the middle container.

[0161] S502, according to the dual-cylinder constant speed and constant pressure displacement system, setting the pressure of the axial confining pressure pump and the radial confining pressure pump to a target pressure value, and setting the heating circulation pump to a third threshold value;

[0162] The experiment was carried out by controlling the associated equipment through a dual-cylinder constant speed and constant pressure displacement system, that is, the axial confining pressure pump and the radial confining pressure pump were increased to the target pressure value to simulate the pressure of the formation in the vertical and horizontal directions, the heating circulation pump was turned on and the core holder was heated to the third threshold value.

[0163] S503, after determining that the internal temperature of the core holder is constant at the third threshold value, controlling the needle valves at the front and rear ends of the core holder to close the valves;

[0164] When the internal temperature of the core holder is constant at the preset third threshold, the needle valves at the front and rear ends of the core holder are closed.

[0165] S504, after determining that the upper end pressure of the core holder reaches the fourth threshold, control the front and rear end needle valves of the core holder to open the valves, and set the outlet pressure value of the back pressure pump to the fifth threshold to establish a target displacement environment.

[0166] When the upper end pressure of the core holder reaches the preset fourth threshold, the front and rear end needle valves of the core holder are opened from top to bottom, and the outlet pressure value of the back pressure pump is set to the fifth threshold. After the pressure value of the back pressure pump reaches the fifth threshold, it is determined that the target displacement environment is established.

[0167] The present application provides a method for simulating tertiary oil recovery after water flooding in a strongly heterogeneous oil reservoir. Before the displacement treatment is carried out, each component in the target displacement device is controlled by preset conditions, and the actual oil production environment is truly simulated. Therefore, while ensuring the authenticity and reliability of the target adopted data after the subsequent displacement treatment, the rapidity and convenience of the target displacement environment establishment process are improved, the cost consumption in manpower, material resources and time is effectively reduced, the technical problem of low oil recovery efficiency in heterogeneous oil reservoirs is solved, and the technical effect of improving the oil recovery efficiency in heterogeneous oil reservoirs is achieved.

[0168] Figure 6 The process of tertiary oil recovery after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application is as follows Figure 4 .like Figure 6 As shown, this embodiment provides a supplementary description of the displacement process of the second core sample based on the above embodiment, including:

[0169] S601, according to the dual-cylinder constant speed and constant pressure displacement system, the displacement pump flow is set to a target flow, and according to the target flow, a standard formation water solution having a target injection volume is injected into the second core sample to perform water flooding treatment;

[0170] The flow rate of the displacement pump is set to the target flow rate through the dual-bar constant speed and constant pressure displacement system, and at the flow rate corresponding to the target flow rate, a standard formation water solution with a volume of the target injection volume is injected into the second core sample for water flooding treatment.

[0171] Specifically, according to the dual-bar constant speed and constant pressure displacement system, the displacement pump flow rate is set to 0.01 ml / min, and a standard formation water solution with a target injection volume is injected into the second core sample, so that the second core sample is water-flooded at a flow rate of 0.01 ml / min.

[0172] S602, after determining that the displacement pump displacement volume reaches the sixth threshold, replacing the standard formation water solution with a chemical displacement agent, and injecting the chemical displacement agent with a target injection volume into the second core sample to perform chemical flooding treatment;

[0173] In this embodiment, the target injection amount is obtained by:

[0174] Determine a corresponding initial weight based on the initial core sample, and determine a corresponding target weight and pore volume based on the second core sample;

[0175] According to the initial weight and the target weight, the corresponding weight difference is determined;

[0176] The corresponding pore volume is obtained according to the weight difference and the density of the standard formation water solution, and the corresponding target injection volume is determined according to the pore volume.

[0177] When the displacement volume of the displacement pump reaches the sixth threshold, the standard formation water solution in the intermediate container is replaced with a chemical displacement agent, and the chemical displacement agent having a volume equal to the target injection volume is injected into the second core sample for chemical flooding treatment.

[0178] Specifically, when the displacement volume of the displacement pump reaches 1PV, the standard formation water solution in the intermediate container is replaced with a chemical displacement agent, and the chemical displacement agent having a target injection volume is injected into the second core sample to perform chemical flooding treatment on the second core sample.

[0179] S603, after determining that the chemical flooding treatment is completed, replacing the chemical flooding agent with a standard formation water solution, and injecting the standard formation water solution with a target injection volume into the second core sample, and performing water flooding treatment on the second core sample;

[0180] When the chemical flooding treatment is completed, the chemical flooding agent in the intermediate container is replaced with the standard formation water solution, and the standard formation water solution with a volume equal to the target injection volume is injected into the second core sample to continue the water flooding treatment.

[0181] S604, after determining that the water flooding treatment is completed, replacing the standard formation water solution with the target gas, and injecting the target gas with a target injection amount into the second core sample to perform gas flooding treatment;

[0182] In this embodiment, the target gas includes but is not limited to carbon dioxide, nitrogen, oxygen, air, flue gas or methane.

[0183] After the water flooding treatment is completed, the standard formation water solution in the intermediate container is replaced with the target gas, and the target gas having a volume equal to the target injection volume is injected into the second core sample to continue the gas flooding treatment.

[0184] S605, monitoring the second core sample according to the target displacement device, and after determining that gas channeling occurs in the second core sample, injecting a chemical plugging agent having a target injection amount into the second core sample for plugging;

[0185] Through the data acquisition imaging system of the target displacement device, the second core sample is continuously detected during the entire displacement process, and the corresponding nuclear magnetic resonance imaging images are collected. Based on these nuclear magnetic resonance imaging images, after gas channeling is found in the second core sample, a chemical plugging agent with a capacity of the target injection amount is injected into the second core sample to perform chemical plugging.

[0186] S606. After determining that there is no gas channeling in the second core sample, the chemical plugging agent is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform gas drive treatment.

[0187] After completing the above-mentioned chemical plugging, the gas channeling of the second core sample is determined based on the nuclear magnetic resonance imaging images collected by the data acquisition imaging system of the target displacement device. After determining that there is no gas channeling in the second core sample, the chemical plugging agent in the intermediate container is replaced with the target gas, and the target gas with a capacity of the target injection volume is injected into the second core sample to continue the gas drive treatment.

[0188] The present application provides a method for simulating tertiary oil recovery after water flooding in a strongly heterogeneous reservoir. By using three different displacement phases, the second core sample is treated with water flooding, chemical flooding and gas flooding respectively. After determining that gas channeling occurs in the second core sample, a chemical plugging agent with a target injection amount is injected into the second core sample for plugging. After determining that there is no gas channeling in the second core sample, the chemical plugging agent is replaced with a target gas, and the target gas with a target injection amount is injected into the second core sample to continue gas flooding treatment. Thus, multiple displacement phases are flexibly used to perform multiple displacement treatments on the second core sample through a target displacement device, which not only significantly improves the convenience and rapidity of the overall displacement treatment process, but also effectively reduces the cost consumption in terms of manpower, material resources and time. At the same time, in the gas flooding process, chemical plugging is performed in consideration of the gas channeling of the second core sample, and gas flooding treatment is continued after plugging, thereby ensuring the accuracy and reliability of the target adopted data after subsequent displacement treatment, solving the technical problem of low oil recovery efficiency in heterogeneous reservoirs, and achieving the technical effect of improving the oil recovery efficiency in heterogeneous reservoirs.

[0189] Figure 7 The process of simulating the tertiary oil recovery method after water flooding in a highly heterogeneous reservoir provided in the embodiment of the present application Figure 5 ,like Figure 7 As shown, this embodiment provides a supplementary description of the process of acquiring target oil production data based on the above embodiment, including:

[0190] S701, obtaining an injection end pressure curve corresponding to the second core sample according to the initial image and the target image corresponding to the water flooding treatment, and determining the injection end pressure change rate of the second core sample with the seepage distance according to the injection end pressure curve;

[0191] In this embodiment, the injection end pressure curve is used to indicate the permeation distance of the displacement phase in the second core sample and the change trend of the injection end pressure with time or the injection amount of the displacement phase during the displacement treatment process. The rate of change of the injection end pressure with the seepage distance is used to quantitatively evaluate the connectivity of the seepage channel of the second core sample. The rate of change of the injection end pressure with the seepage distance is positively correlated with the connectivity of the seepage channel. The higher the rate of change of the injection end pressure with the seepage distance, the better the connectivity of the seepage channel of the second core sample.

[0192] The data acquisition imaging system in the target displacement device continuously detects the second core sample during the entire displacement treatment process and collects nuclear magnetic resonance imaging images during the entire treatment process. Among these nuclear magnetic resonance imaging images, the initial image of the second core sample before the displacement treatment and the target image after the water flooding treatment are obtained for analysis. By observing the pressure at the injection port of the second core sample in the initial image and the target image after the water flooding treatment and the permeation distance after the injection displacement phase, the injection end pressure curve corresponding to the second core sample is determined, and based on the curve, the rate of change of the injection end pressure of the second core sample with the seepage distance is determined.

[0193] S702, obtaining an initial signal amount corresponding to the initial image according to the data acquisition imaging system, and obtaining a target signal amount corresponding to each target image according to each target image;

[0194] The initial signal amplitude corresponding to the initial image of the second core sample before the displacement treatment is obtained through the data acquisition imaging system in the target displacement device, and the initial signal amplitude is integrated to obtain the corresponding initial signal amount. At the same time, multiple target images of the second core sample after the above-mentioned water drive, chemical drive and gas drive treatment are obtained, and based on these target images, the corresponding target signal amplitudes are respectively obtained, and each target signal amplitude is integrated to obtain the corresponding multiple target signal amounts.

[0195] S703: Determine the recovery rate of the second core sample according to the initial signal amount and the target signal amount.

[0196] The initial signal amount and each target signal amount are summed up and the difference is calculated, and the ratio of the difference to the initial signal amount is used as the recovery factor of the second core sample.

[0197] Figure 8 Schematic diagram of the target image provided in the embodiment of the present application, the data acquisition imaging system in the target displacement device continuously monitors the second core sample before and after the second core sample is subjected to displacement treatment, wherein the original oil-containing image corresponding to the second core sample before the displacement treatment, the nuclear magnetic imaging image corresponding to the replacement volume of 0.5PV and 2PV during the water flooding treatment, the nuclear magnetic imaging image corresponding to the replacement volume of 0.5PV during the chemical flooding treatment, and the nuclear magnetic imaging image corresponding to the replacement volume of 1PV during the gas flooding treatment are shown as follows Figure 8 As shown, it can be understood that Figure 8 It is only a schematic diagram of the target image and does not affect the protection content of the embodiments of the present application.

[0198] Fig. 9 This is a schematic diagram of the structure of the tertiary oil recovery device for simulating water flooding of a highly heterogeneous reservoir provided in an embodiment of the present application. The device of this embodiment can be in the form of software and / or hardware. Fig. 9As shown, the tertiary oil recovery device 900 for simulating water flooding of a strongly heterogeneous reservoir provided in an embodiment of the present application includes: a first acquisition module 901, a second acquisition module 902, a first processing module 903, a control module 904 and a second processing module 905:

[0199] The first acquisition module 901 is used to determine the corresponding formation grain size distribution information according to the drilling and logging data of the target reservoir to obtain the corresponding initial core sample, wherein the initial core sample is a heterogeneous core sample prepared after simulating the formation grain size distribution;

[0200] The second acquisition module 902 is used to perform a displacement saturation treatment on the first core sample using a standard formation water solution and formation crude oil to obtain a second core sample, wherein the first core sample is a core sample obtained by drying the initial core sample, and the second core sample is a core sample obtained by performing a displacement saturation treatment on the first core sample;

[0201] The first processing module 903 is used to place the second core sample and the standard formation water solution into the target displacement device to establish a target displacement environment, and control the target displacement device to monitor the second core sample in real time according to the target displacement environment;

[0202] The second processing module 904 is used to obtain the corresponding initial image according to the target displacement device, and use multiple displacement phases to perform multiple displacement treatments on the second core sample, wherein the displacement phase includes a chemical displacement agent, a standard formation water solution and a target gas, the displacement treatment includes a chemical displacement treatment, a water displacement treatment and a gas displacement treatment, the chemical displacement agent includes a chemical plugging agent or a cross-linking agent, and the initial image is used to indicate the nuclear magnetic resonance imaging image of the second core sample before the displacement treatment;

[0203] The third acquisition module 905 is used to obtain the corresponding target image according to the target displacement device when each displacement treatment is completed, and determine the target oil production data according to the initial image and the target image, wherein the target oil production data includes the injection end pressure change rate with the seepage distance and the recovery rate. The target image is used to indicate the nuclear magnetic resonance imaging image of the second core sample after each displacement treatment is completed, and each displacement treatment corresponds to a target image.

[0204] In a possible implementation, the second acquisition module 902 is further configured to:

[0205] subjecting the experimental beaker with the initial core sample to vacuum treatment, and adding simulated formation water solution into the vacuum treated experimental beaker;

[0206] After confirming that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on the surface of the initial core sample, the initial core sample is subjected to water flooding treatment using a standard formation water solution to obtain a third core sample after treatment;

[0207] Using formation crude oil, the third core sample is subjected to displacement saturation treatment to obtain a fourth core sample after treatment;

[0208] After placing the fourth core sample into the formation crude oil and pressurizing it to a target pressure, the fourth core sample is subjected to a static treatment;

[0209] After determining that the static time of the fourth core sample reaches the first threshold, the corresponding second core sample is obtained.

[0210] In a possible implementation, the first processing module 903 is also used for a target displacement device, including:

[0211] a core holder for fixing and holding the second core sample;

[0212] a displacement pump for controlling the flow rate of the displacement phase and the rate at which the second core sample is injected;

[0213] An intermediate container for storing and supplying the displacement phase required for the displacement treatment;

[0214] Dual-cylinder constant speed and constant pressure displacement system, used to control and adjust the working state of the displacement pump;

[0215] Axial confining pressure pump, used to simulate the pressure of the formation in the vertical direction;

[0216] Radial confining pressure pump, used to simulate the horizontal pressure of the formation;

[0217] A heated circulation pump to set and maintain the internal temperature of the core holder;

[0218] Needle valves at the front and rear ends of the core holder are used to control the injection and discharge of the displacement phase at the front and rear ends of the core holder;

[0219] A magnet, used to generate a stable magnetic field environment;

[0220] The data acquisition imaging system is used to monitor and collect nuclear magnetic imaging images in real time during the displacement process according to the magnetic field environment, and determine the signal quantity corresponding to the nuclear magnetic imaging images;

[0221] Back pressure pump, used to set the outlet pressure value required for displacement treatment, and to adjust and control the back pressure during displacement treatment;

[0222] The measuring cylinder is used to receive the produced liquid generated when the pressure of the back pressure pump valve is released when it is determined that the pressure corresponding to the back pressure pump reaches the second threshold.

[0223] In a possible implementation, the first processing module 903 is further configured to:

[0224] According to the target displacement device, a second core sample is fixed to the core holder, and a standard formation water solution is placed in an intermediate container;

[0225] According to the dual-cylinder constant speed and constant pressure displacement system, the pressures of the axial confining pressure pump and the radial confining pressure pump are set to target pressure values, and the heating circulation pump is set to a third threshold value;

[0226] After determining that the temperature inside the core holder is constant at the third threshold, controlling the needle valves at the front and rear ends of the core holder to close the valves;

[0227] After determining that the upper end pressure of the core holder reaches the fourth threshold, the front and rear end needle valves of the core holder are controlled to open the valves, and the outlet pressure value of the back pressure pump is set to the fifth threshold to establish the target displacement environment.

[0228] In a possible implementation, the second processing module 904 is further configured to:

[0229] According to the dual-cylinder constant speed and constant pressure displacement system, the displacement pump flow rate is set to a target flow rate, and according to the target flow rate, a standard formation water solution having a target injection volume is injected into the second core sample to perform water flooding treatment;

[0230] After determining that the displacement pump displacement volume reaches the sixth threshold, replacing the standard formation water solution with a chemical displacement agent, and injecting the chemical displacement agent with a target injection volume into the second core sample to perform chemical flooding treatment;

[0231] After confirming that the chemical flooding treatment is completed, the chemical flooding agent is replaced with a standard formation water solution, and the standard formation water solution having a target injection volume is injected into the second core sample, and the second core sample is subjected to water flooding treatment;

[0232] After it is determined that the water flooding treatment is completed, the standard formation water solution is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform the gas flooding treatment.

[0233] In a possible implementation, the second processing module 904 is further configured to:

[0234] Determine a corresponding initial weight based on the initial core sample, and determine a corresponding target weight and pore volume based on the second core sample;

[0235] According to the initial weight and the target weight, the corresponding weight difference is determined;

[0236] The corresponding pore volume is obtained according to the weight difference and the density of the standard formation water solution, and the corresponding target injection volume is determined according to the pore volume.

[0237] In a possible implementation, the second processing module 904 is further configured to:

[0238] The second core sample is monitored according to the target displacement device;

[0239] After determining that gas channeling occurs in the second core sample, injecting a chemical plugging agent having a target injection amount into the second core sample for plugging;

[0240] After confirming that there is no gas channeling in the second core sample, the chemical plugging agent is replaced with the target gas, and the target gas having a target injection volume is injected into the second core sample to perform gas drive treatment.

[0241] In a possible implementation, the third acquisition module 905 is further configured to:

[0242] According to the initial image and the corresponding target image after water flooding treatment, the injection end pressure curve corresponding to the second core sample is obtained, wherein the injection end pressure curve is used to indicate the penetration distance of the displacement phase in the second core sample during the displacement treatment process and the variation trend of the injection end pressure with time or the injection amount of the displacement phase;

[0243] According to the injection end pressure curve, determine the injection end pressure change rate of the second core sample with the seepage distance;

[0244] According to the data acquisition imaging system, an initial signal amount corresponding to the initial image is obtained, and according to each target image, a target signal amount corresponding to each target image is obtained;

[0245] The recovery factor of the second core sample is determined based on the initial signal amount and the target signal amount.

[0246] The present application provides a tertiary oil recovery device for simulating water flooding of a strongly heterogeneous reservoir, which can implement the above method embodiment. Its implementation principle and technical effects are similar, and this embodiment will not be repeated here.

[0247] Fig.10 This is a hardware structure diagram of the tertiary oil recovery equipment for simulating water flooding of a highly heterogeneous reservoir provided in the embodiment of the present application. Fig.10 As shown, the tertiary oil recovery equipment 1000 for simulating water flooding of a strongly heterogeneous reservoir includes:

[0248] Processor 1001 and memory 1002;

[0249] Memory stores computer-executable instructions;

[0250] The processor executes the computer execution instructions stored in the memory 1002, so that the tertiary oil recovery equipment after simulating water flooding in a strongly heterogeneous oil reservoir executes the tertiary oil recovery method after water flooding in a simulated strongly heterogeneous oil reservoir as described above.

[0251] It should be understood that the processor 1001 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the invention can be directly implemented as a hardware processor, or can be implemented by a combination of hardware and software modules in the processor.

[0252] The memory 1002 may include a high-speed random access memory (RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory, and may also be a USB flash drive, a mobile hard disk, a read-only memory, a disk or an optical disk, etc.

[0253] The embodiment of the present application correspondingly provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the above-mentioned tertiary oil recovery method after water flooding of a simulated highly heterogeneous oil reservoir.

[0254] The embodiment of the present application also provides a computer program product. When the computer program is executed by a processor, it is used to implement the above-mentioned tertiary oil recovery method after water flooding of a highly heterogeneous oil reservoir.

[0255] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0256] It should be further noted that, although the various steps in the flowchart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowchart may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0257] It should be understood that the above-mentioned device embodiments are only illustrative, and the device of the present application can also be implemented in other ways. For example, the division of units / modules in the above-mentioned embodiments is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0258] In addition, unless otherwise specified, each functional unit / module in each embodiment of the present application may be integrated into one unit / module, each unit / module may exist physically separately, or two or more units / modules may be integrated together. The above-mentioned integrated unit / module may be implemented in the form of hardware or in the form of a software program module.

[0259] If the integrated unit / module is implemented in the form of hardware, the hardware may be a digital circuit, an analog circuit, etc. The physical implementation of the hardware structure includes but is not limited to transistors, memristors, etc. Unless otherwise specified, the processor may be any appropriate hardware processor, such as a CPU, a GPU, an FPGA, a DSP, an ASIC, etc. Unless otherwise specified, the storage unit may be any appropriate magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory (RRAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), an enhanced dynamic random access memory (EDRAM), a high-bandwidth memory (HBM), a hybrid memory cube (HMC), etc.

[0260] If the integrated unit / module is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0261] In the above embodiments, the description of each embodiment has its own emphasis. For the part not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0262] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0263] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for tertiary oil recovery after water flooding in a simulated highly heterogeneous reservoir, characterized in that: include: Determine the corresponding formation grain size distribution information according to the drilling and logging data of the target reservoir to obtain the corresponding initial core sample, wherein the initial core sample is a heterogeneous core sample prepared after simulating the formation grain size distribution; Using a standard formation water solution and formation crude oil, the first core sample is subjected to a displacement saturation treatment to obtain a second core sample, wherein the first core sample is a core sample obtained by drying the initial core sample, and the second core sample is a core sample obtained by displacing and saturating the first core sample; placing the second core sample and the standard formation water solution into a target displacement device to establish a target displacement environment, and controlling the target displacement device to monitor the second core sample in real time according to the target displacement environment; According to the target displacement device, a corresponding initial image is obtained, and multiple displacement phases are used to perform multiple displacement treatments on the second core sample, wherein the displacement phases include a chemical displacement agent, the standard formation water solution and a target gas, the displacement treatment includes a chemical displacement treatment, a water displacement treatment and a gas displacement treatment, the chemical displacement agent includes a chemical plugging agent or a cross-linking agent, and the initial image is used to indicate a nuclear magnetic resonance imaging image of the second core sample before the displacement treatment; When each displacement treatment is completed, a corresponding target image is obtained according to the target displacement device, and corresponding target oil production data is determined according to the initial image and the target image, wherein the target oil production data includes the rate of change of injection end pressure with seepage distance and the recovery rate, and the target image is used to indicate the nuclear magnetic resonance imaging image of the second core sample after each displacement treatment is completed, and each displacement treatment corresponds to one target image.

2. The method according to claim 1, characterized in that The method of using a standard formation water solution and formation crude oil to perform displacement saturation treatment on the first core sample to obtain a second core sample includes: subjecting the experimental beaker with the initial core sample to vacuum treatment, and adding simulated formation water solution into the experimental beaker after vacuum treatment; After determining that the water surface of the simulated formation water solution submerges the initial core sample and there are no obvious bubbles on the surface of the initial core sample, using the standard formation water solution to perform the water flooding treatment on the initial core sample to obtain a third core sample after treatment; Using the formation crude oil, performing the displacement saturation treatment on the third core sample to obtain a fourth core sample after the treatment; After placing the fourth core sample into the formation crude oil and pressurizing it to a target pressure, the fourth core sample is subjected to a static treatment; After determining that the static time of the fourth core sample reaches the first threshold, the corresponding second core sample is obtained.

3. The method according to claim 2, characterized in that The target displacement device comprises: a core holder, used for fixing and clamping the second core sample; a displacement pump for controlling the flow rate of the displacement phase and the speed of injecting the second core sample; An intermediate container for storing and supplying the displacement phase required for the displacement process; A dual-cylinder constant speed and constant pressure displacement system, used to control and adjust the working state of the displacement pump; Axial confining pressure pump, used to simulate the pressure of the formation in the vertical direction; Radial confining pressure pump, used to simulate the horizontal pressure of the formation; a heating circulation pump for setting and maintaining the internal temperature of the core holder; Needle valves at the front and rear ends of the core holder are used to control the injection and discharge of the displacement phase at the front and rear ends of the core holder; A magnet, used to generate a stable magnetic field environment; A data acquisition imaging system, used to monitor and collect the nuclear magnetic imaging pictures in the displacement process in real time according to the magnetic field environment, and determine the signal quantity corresponding to the nuclear magnetic imaging pictures; A back pressure pump, used to set the outlet pressure value required for the displacement process, and to adjust and control the back pressure in the displacement process; The measuring cylinder is used to receive the produced liquid generated when the pressure of the back-pressure pump valve is released when it is determined that the pressure corresponding to the back-pressure pump reaches a second threshold.

4. The method according to claim 3, characterized in that The step of placing the second core sample and the standard formation water solution into a target displacement device to establish a target displacement environment includes: According to the target displacement device, fixing the second core sample to the core holder and placing the standard formation water solution into the intermediate container; According to the dual-cylinder constant speed and constant pressure displacement system, the pressures of the axial confining pressure pump and the radial confining pressure pump are set to target pressure values, and the heating circulation pump is set to a third threshold value; After determining that the temperature inside the core holder is constant at the third threshold, controlling the needle valves at the front and rear ends of the core holder to close the valves; After determining that the upper end pressure of the core holder reaches the fourth threshold, the front and rear end needle valves of the core holder are controlled to open the valves, and the outlet pressure value of the back pressure pump is set to the fifth threshold to establish the target displacement environment.

5. The method according to claim 4, characterized in that The method of using multiple displacement phases to perform multiple displacement treatments on the second core sample includes: According to the dual-cylinder constant speed and constant pressure displacement system, the displacement pump flow is set to a target flow, and according to the target flow, the standard formation water solution having a target injection volume is injected into the second core sample to perform the water flooding treatment; After determining that the displacement pump displacement volume reaches a sixth threshold, replacing the standard formation water solution with the chemical displacement agent, and injecting the chemical displacement agent with a target injection volume into the second core sample to perform the chemical flooding treatment; After determining that the chemical flooding treatment is completed, replacing the chemical flooding agent with the standard formation water solution, and injecting the standard formation water solution having the target injection volume into the second core sample, and performing the water flooding treatment on the second core sample; After it is determined that the water flooding treatment is completed, the standard formation water solution is replaced with the target gas, and the target gas having the target injection amount is injected into the second core sample to perform the gas flooding treatment.

6. The method according to claim 5, characterized in that The target injection volume is obtained by: Determining a corresponding initial weight based on the initial core sample, and determining a corresponding target weight and pore volume based on the second core sample; Determining a corresponding weight difference according to the initial weight and the target weight; The corresponding pore volume is obtained according to the weight difference and the density of the standard formation water solution, and the corresponding target injection volume is determined according to the pore volume.

7. The method according to claim 6, characterized in that After injecting the target gas having the target injection amount into the second core sample to perform the gas drive treatment, the method further includes: monitoring the second core sample according to the target displacement device; After determining that gas channeling occurs in the second core sample, injecting the chemical plugging agent having a target injection amount into the second core sample for plugging; After determining that there is no gas channeling in the second core sample, the chemical plugging agent is replaced with the target gas, and the target gas having the target injection amount is injected into the second core sample to perform the gas drive treatment.

8. The method according to claim 6, characterized in that Determining corresponding target oil production data according to the initial image and the target image includes: According to the initial image and the target image corresponding to the water flooding treatment, an injection end pressure curve corresponding to the second core sample is obtained, wherein the injection end pressure curve is used to indicate the penetration distance of the displacement phase in the second core sample and the variation trend of the injection end pressure with time or the injection amount of the displacement phase during the displacement treatment process; Determining the rate of change of the injection end pressure of the second core sample with seepage distance according to the injection end pressure curve; According to the data acquisition imaging system, an initial signal amount corresponding to the initial image is obtained, and according to each of the target images, a target signal amount corresponding to each of the target images is obtained; The recovery factor of the second core sample is determined according to the initial signal amount and the target signal amount.

9. A tertiary oil recovery equipment for simulating water flooding in a highly heterogeneous reservoir, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 8 when executed by a processor.

Images