Displacement perturbation simulation system and method

Abstract

The invention discloses a displacement perturbation simulation system and method, and relates to the field of displacement. According to the displacement disturbance simulation system and method, water and displacement fluid are sequentially pressurized and preheated through a fluid injection pipe by arranging a fluid injection system and then injected into a rock core clamped by a rock core clamping system for water saturation and displacement operation; adjusting gas-liquid fluid discharged from the rock core to preset pressure through a fluid discharge pipe, discharging the gas-liquid fluid to a backpressure control monitoring and metering system for gas-liquid separation, respectively detecting the volume, temperature and pressure of a gas phase and a liquid phase after gas-liquid separation, and then calculating to obtain the final injection amount, the gas phase accumulated output amount and the water phase accumulated output amount of the displacement fluid; therefore, a high-temperature, high-pressure and high-flow displacement injection test of a large-size rock core can be carried out to explore the physical process of gas oil displacement and gas displacement in a deep reservoir.

Description

Technical Field

[0001] The present application relates to the field of displacement, and in particular, to a displacement displacement disturbance simulation system and method. Background Art

[0002] Gas displacement technology has attracted extensive attention and research as an effective means to increase the production of oil, coalbed methane and shale gas and achieve geological storage of carbon dioxide. However, the application of gas displacement technology is still not widespread, and people still lack understanding of the displacement process. In order to meet the high-pressure loading requirements, the existing displacement experimental devices are mainly designed for small-sized cores, usually using 25×50mm, 50×100mm cylinders or 300mm cube cores for experiments. These smaller core sizes often correspond to smaller pore volumes, and gas injection and control are less difficult. At the same time, due to the small core size, the existing displacement experiments are often carried out on the entire end face of the core, and it is impossible to achieve accurate displacement of specific areas, which is quite different from the actual production situation of oil and gas fields. In addition, the existing displacement methods are mainly constant pressure injection, constant flow injection or cyclic injection. This type of displacement method does not consider the formation of dominant seepage channels during the displacement process, and it is impossible to adjust the displacement scheme according to the actual displacement situation, resulting in low displacement efficiency and poor effect. Summary of the invention

[0003] The purpose of the present application is to provide a displacement perturbation simulation system and method, which can carry out high-temperature, high-pressure and large-flow displacement injection tests on large-size cores to explore the physical processes of gas oil and gas displacement in deep reservoirs, and obtain accurate final injection volume of displacement fluid, cumulative gas phase output and cumulative water phase output.

[0004] This application is implemented as follows:

[0005] The present application provides a displacement perturbation simulation system, comprising:

[0006] at least one fluid injection system, the fluid injection system comprising a gas cylinder, a gas booster, a pressure-resistant container and a first plunger pump connected in sequence through a pipeline;

[0007] A fluid injection pipe is connected to the first plunger pump of each fluid injection system, and a first back pressure controller, a preheater and a first pressure sensor are sequentially arranged on the fluid injection pipe;

[0008] The core clamping system comprises two end pads for pressing and clamping the two ends of the core, and a plurality of displacement areas are arranged on the end pads, each displacement area comprises a displacement hole arranged on the end pad, a plurality of annular displacement channels sleeved outside the displacement hole, and a plurality of radial displacement channels extending radially along the displacement hole, and each radial displacement channel is connected with the displacement hole and each corresponding annular displacement channel; the fluid injection pipe is connected with each displacement hole of an end pad through a pipeline provided with a first connecting valve;

[0009] A fluid discharge pipe is connected to each displacement hole of the other end pad through a pipeline provided with a second connecting valve, and a second pressure sensor is provided on the fluid discharge pipe;

[0010] The back pressure control monitoring and metering system includes a second back pressure controller connected to the fluid discharge pipe, a gas-liquid separation device connected to the second back pressure controller, a gas metering device and a second plunger pump respectively connected to the gas-liquid separation device, and a camera device for collecting liquid surface images in the gas-liquid separation device. The gas metering device is connected to a gas component detection device.

[0011] In some optional embodiments, at least one fluid injection system includes a refrigerated water bath device, which is used to adjust the temperature of the corresponding pressure-resistant container and the first plunger pump to 0-25 degrees.

[0012] In some optional embodiments, at least one fluid injection system includes a piston container, and the piston container is connected to the outlet of the corresponding first piston pump through a pipeline provided with a container control valve.

[0013] In some optional embodiments, the pipeline between the gas cylinder and the gas booster is provided with a first control valve, and / or the pipeline between the gas booster and the pressure container is provided with a second control valve.

[0014] In some optional embodiments, the pipeline connected to the inlet of the first plunger pump is provided with a third control valve, and / or the pipeline connected to the outlet of the first plunger pump is provided with a fourth control valve.

[0015] In some optional embodiments, the core clamping system further comprises at least one intermediate tube, the two ends of which are respectively connected to the fluid injection tube and the fluid discharge tube, and the intermediate tube is provided with a fifth control valve, a differential pressure gauge and a sixth control valve.

[0016] The present application also provides a displacement perturbation simulation method, which comprises the following steps:

[0017] The two end pads are respectively pressed against the two ends of the core and then clamped and fixed, and a plurality of displacement areas are arranged on the end pads, each displacement area includes a displacement hole arranged on the end pad, a plurality of annular displacement channels sleeved outside the displacement hole, and a plurality of radial displacement channels extending radially along the displacement hole, and each radial displacement channel is connected with the displacement hole and each corresponding annular displacement channel;

[0018] After adjusting the water to the preset temperature and pressure, the water is passed into each displacement hole of the end pad to saturate the core with water;

[0019] A displacement fluid is adjusted to a preset pressure by a first plunger pump and then uniformly introduced into each displacement hole of a pad at one end, and a gas-liquid mixed fluid in each displacement hole of a pad at the other end is uniformly discharged and then transported to a second back pressure controller for gas-liquid separation, and the volumes of the gas phase and the liquid phase of the gas-liquid separation are respectively detected;

[0020] The injection amount of the displacement fluid and the gas phase output and liquid phase output of the gas-liquid separation are respectively corrected and calculated to obtain the final injection amount of the displacement fluid, the cumulative output of the gas phase and the cumulative output of the water phase.

[0021] In some optional embodiments, the displacement fluid is adjusted to a preset temperature and pressure and then uniformly introduced into each displacement hole of an end pad according to the following formula:

[0022]

[0023] In the formula, k i is the number of each displacement hole into which the displacement fluid is introduced, F i When it is 0, it means that the displacement fluid is stopped from being injected into the corresponding displacement hole. i When it is 1, it means that the displacement fluid is injected into the corresponding displacement hole, and the injection and stop of the displacement fluid in each displacement hole are controlled by a valve; I(k i ) is the corresponding resistivity of each displacement hole at the 1 / 4 depth projection inside the end face of the core fluid injection end;

[0024] And / or, the gas-liquid mixed fluid in each displacement hole of the other end pad is uniformly discharged according to the following formula to perform gas-liquid separation:

[0025]

[0026] In the formula, k j is the number of each displacement hole that discharges the gas-liquid mixed fluid, F j When it is 0, it means that the gas-liquid mixed fluid is stopped from being discharged from the corresponding displacement hole. j When it is 1, it means that the gas-liquid mixed fluid is discharged from the corresponding displacement hole, and the discharge and stop of the gas-liquid mixed fluid in each displacement hole are controlled by a valve; I(k j) is the corresponding resistivity of each displacement hole at the 1 / 4 depth projection inside the end face of the core fluid discharge end.

[0027] In some optional embodiments, the following formula is used to correct the displacement fluid injection amount to obtain the final displacement fluid injection amount:

[0028]

[0029] In the formula, p inj is the injection pressure of the first plunger pump when injecting the displacement fluid into each displacement hole; p1 is the final pressure when the displacement fluid is injected into each displacement hole; ΔV pump V is the cumulative change in the volume of the displacement fluid in the first plunger pump during the process of injecting the displacement fluid into each displacement hole; u (dead) is the volume of the pipeline between the first plunger pump and each displacement hole into which the displacement fluid is injected; Z inj is the compressibility of the fluid in the first plunger pump; Z1 is the compressibility of the fluid in the pipeline between the first plunger pump and each displacement hole into which the displacement fluid is injected; T inj is the temperature of the fluid in the first plunger pump; T1 is the temperature of the fluid in the pipeline between the first plunger pump and each displacement hole into which the displacement fluid is injected.

[0030] In some optional embodiments, the gas phase output of gas-liquid separation is corrected and calculated according to the following formula to obtain the gas phase cumulative output:

[0031] Pro(water)=V water -V u (dead)-V d (dead);

[0032] Where V water V is the liquid production obtained by detecting the volume of the liquid phase in gas-liquid separation under atmospheric pressure; u (dead) is the volume of the pipeline between the first plunger pump and each displacement hole into which the displacement fluid is injected; V d (dead) is the volume of the pipeline between each displacement hole for discharging the gas-liquid mixed fluid and the second back pressure controller;

[0033] The cumulative output of the water phase is calculated by correcting the liquid phase output of gas-liquid separation according to the following formula:

[0034]

[0035] Where V gasIt is the gas production obtained by detecting the volume of the gas phase of gas-liquid separation under atmospheric pressure; p0 is the atmospheric pressure; p2 is the pressure in the pipeline between each displacement hole for discharging the gas-liquid mixed fluid and the second back pressure controller; Z0 is the compressibility of the fluid under atmospheric pressure; Z2 is the compressibility of the fluid in the pipeline between each displacement hole for discharging the gas-liquid mixed fluid and the second back pressure controller; T0 is the temperature of the fluid under atmospheric pressure; T2 is the temperature of the fluid in the pipeline between each displacement hole for discharging the gas-liquid mixed fluid and the second back pressure controller.

[0036] The beneficial effects of the present application are as follows: the displacement perturbation simulation system and method provided by the present application, by setting up a fluid injection system, sequentially pressurizes and preheats water and displacement fluid through a fluid injection pipe and then injects them into the core clamped by the core clamping system to perform water saturation and displacement operations, and adjusts the gas-liquid fluid discharged from the core to a preset pressure through a fluid discharge pipe and discharges it to a back pressure control monitoring and metering system for gas-liquid separation, and detects the volume, temperature and pressure of the gas phase and liquid phase after gas-liquid separation respectively, and then calculates the final injection amount of the displacement fluid, the cumulative output of the gas phase and the cumulative output of the water phase, so that high-temperature, high-pressure and large-flow displacement injection tests of large-size cores can be carried out to explore the physical processes of gas oil displacement and gas displacement in deep reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the structure of a displacement perturbation simulation system provided in an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the structure of an end pad in a displacement perturbation simulation system provided in an embodiment of the present application;

[0040] Figure 3 for Figure 2 A schematic diagram of the local enlarged structure at point A in the middle;

[0041] Figure 4 A schematic diagram of the structure of arranging water saturation measurement points inside a core in a displacement displacement disturbance simulation method provided in an embodiment of the present application;

[0042] Figure 5 A schematic structural diagram of a displacement disturbance simulation system provided in another embodiment of the present application.

[0043] In the figure: 100, fluid injection system; 110, gas cylinder; 120, gas booster; 130, pressure container; 140, first plunger pump; 150, refrigeration water bath device; 160, piston container; 170, container control valve; 180, first control valve; 190, second control valve; 191, third control valve; 192, fourth control valve; 200, fluid injection pipe; 210, first back pressure controller; 220, preheater; 230, first pressure sensor; 240, first connecting valve; 250, fluid discharge pipe; 260, second connecting valve; 2 70. Second pressure sensor; 300. Core clamping system; 310. End pad; 311. Displacement area; 312. Displacement hole; 313. Annular displacement channel; 314. Radial displacement channel; 320. Intermediate pipe; 330. Fifth control valve; 340. Differential pressure gauge; 350. Sixth control valve; 400. Back pressure control monitoring and metering system; 410. Second back pressure controller; 420. Gas-liquid separation device; 430. Gas metering device; 440. Second plunger pump; 450. Camera device; 460. Gas component detection device; 500. Core. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0047] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0048] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0049] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] The features and performance of the displacement perturbation simulation system and method of the present application are further described in detail below in conjunction with the embodiments.

[0052] like Figure 1 , Figure 2 , Figure 3As shown, the embodiment of the present application provides a displacement disturbance simulation system, including two fluid injection systems 100, a fluid injection pipe 200, a core clamping system 300, a fluid discharge pipe 250 and a back pressure control monitoring and metering system 400;

[0053] Among them, the two fluid injection systems 100 each include a gas cylinder 110, a gas booster 120, a pressure-resistant container 130 and a first plunger pump 140 connected in sequence through pipelines. In each fluid injection system 100, the pipeline between the gas cylinder 110 and the gas booster 120 is provided with a first control valve 180, and in each fluid injection system 100, the pipeline between the gas booster 120 and the pressure-resistant container 130 is provided with a second control valve 190. In each fluid injection system 100, the pipelines connecting the inlet and outlet of the first plunger pump 140 are respectively provided with a third control valve 191 and a fourth control valve 192; one fluid injection system 100 also includes a refrigerated water bath device 150, which is used to adjust the temperature of the corresponding pressure-resistant container 130 and the first plunger pump 140 to 0-25 degrees; the other fluid injection system 100 The fluid injection system 100 also includes a piston container 160, which is connected to the outlet of the corresponding first plunger pump 140 through a pipeline provided with a container control valve 170; the gas booster 120 is used to increase the fluid pressure and then output it. In this embodiment, the gas booster 120 can increase the fluid pressure to 40Mpa before outputting it; the plunger pump is a double pump design, with a single pump chamber volume of 300ml, a maximum flow rate of 180ml / min, and a maximum injection pressure of 70MPa; the pressure-resistant container 130 has a capacity of 5L and a pressure resistance of 70MPa, and is used to provide a stable gas source for high-pressure fluid injection; the piston container 160 has a capacity of 3L, is made of 2205 high-strength stainless steel, and has a pressure resistance of 70MPa, and can realize the injection of gas, water, and weakly corrosive media (such as hydrochloric acid, hydrofluoric acid, and acetic acid). The back pressure controller is used to control the pressure of the fluid flowing through, and the maximum control pressure is 70MPa.

[0054] One end of the fluid injection pipe 200 is connected to the outlet of the first plunger pump 140 of each fluid injection system 100, and the fluid injection pipe 200 is provided with a first back pressure controller 210, a preheater 220 and a first pressure sensor 230 in sequence as it moves away from the fluid injection system 100; the preheater 220 is used to heat the flowing fluid to 10-200 degrees Celsius.

[0055] The core clamping system 300 includes two end pads 310 for pressing and clamping the two ends of the core 500. The end pads 310 are square and have four square displacement areas 311 on one side of the surface facing the core 500. The center of each displacement area 311 is provided with a displacement hole 312 provided on the end pad 310. Each displacement area 311 is also provided with an annular displacement channel 313 arranged radially and spaced along the displacement hole 312 and sleeved on the outer side of the displacement hole 312, and six radial displacement channels 314 extending radially along the displacement hole 312. The six radial displacement channels 31 The radial displacement channels 314 are arranged at intervals along the displacement hole 312 in the circumferential direction, and each radial displacement channel 314 is connected with the displacement hole 312 and each corresponding annular displacement channel 313; the other end of the fluid injection pipe 200 is connected with each displacement hole 312 of an end pad 310 through a pipeline provided with a first connecting valve 240; the core clamping system 300 also includes three intermediate pipes 320, both ends of the intermediate pipes 320 are connected with the fluid injection pipe 200 and the fluid discharge pipe 250 through a three-way interface, and the intermediate pipes 320 are provided with a fifth control valve 330, a differential pressure gauge 340 and a sixth control valve 350.

[0056] One end of the fluid discharge pipe 250 is connected to each displacement hole 312 of the other end pad 310 through a pipeline provided with a second connecting valve 260, and a second pressure sensor 270 is provided on the fluid discharge pipe 250;

[0057] The back pressure control monitoring and metering system 400 includes a second back pressure controller 410 connected to the other end of the fluid discharge pipe 250 through a pipeline, a gas-liquid separation device 420 connected to the second back pressure controller 410 through a pipeline, a gas metering device 430 and a second plunger pump 440 connected to the gas-liquid separation device 420 through pipelines, and a camera device 450 for collecting liquid surface images in the gas-liquid separation device 420. The gas metering device 430 is connected to a gas component detection device 460 through a pipeline.

[0058] The present application also provides a displacement perturbation simulation method, which is performed using the above-mentioned displacement perturbation simulation device and includes the following steps:

[0059] Step 1: Figure 4As shown, the core is cut into a cube of 800mm×800mm×800mm for testing, and a three-dimensional coordinate system is established with the bottom center of the core as the origin. Two groups of water saturation measurement points are arranged in the core. The first group of water saturation measurement points are K1-1, K2-1, K3-1 and K4-1. The coordinates of the first group of water saturation measurement points are (-200mm, -200mm, 600mm), (200mm, -200mm, 600mm), (-200mm, -200mm, 200mm), and (200mm, -200mm, 200mm). The second group of water saturation measurement points are K1-2, K2-2, K3-2 and K4-2, and their coordinates are (-200mm, 200mm, 600mm), (200mm, 200mm, 600mm), (-200mm, 200mm, 200mm), (200mm, 200mm, 200mm); the displacement perturbation simulation device is assembled, and the two end pads 310 are respectively pressed against the two ends of the core 500 for clamping and fixing, so that the projections of the four displacement holes 312 on the end pad 310 for introducing the displacement fluid at one end of the core, i.e., the end face of the injection fluid end, fall on K1-1, K2-1, K3-1 and K4-1 respectively, and the projections of the four displacement holes 312 on the end pad 310 for discharging the gas-liquid mixed fluid at the other end of the core, i.e., the end face of the discharge fluid end, fall on K1-2, K2-2, K3-2 and K4-2 respectively;

[0060] Step 2: adjust the first back pressure controller 210 on the fluid injection pipe 200 to control the output pressure of the fluid and the heating temperature of the preheater 220, and adjust the second back pressure controller 410 in the back pressure control monitoring metering system 400 to control the output pressure of the fluid at the outlet; inject water into the piston container 160, control the container control valve 170 and the fourth control valve 192 in the corresponding fluid injection system 100 to open, control each first connecting valve 240 to open, use the first plunger pump 140 in the fluid injection system 100 where the piston container 160 is located to adjust the water in the piston container 160 to a preset pressure through the first back pressure controller 210 and heat it to a preset temperature through the preheater 220, and then pass it into each displacement hole 312 of the end pad 310 to saturate the core 500 with water, and close the container control valve 170 and the fourth control valve 192 after saturation;

[0061] Step 3: Adjust the temperature of the refrigerated water bath of the refrigerated water bath device 150 to 5 degrees Celsius, open the gas cylinder 110, the first control valve 180, the second control valve 190, and the third control valve 191 in the fluid injection system 100 where the refrigerated water bath device 150 is located, so that the liquid carbon dioxide in the gas cylinder 110 is pressurized by the gas booster 120 and enters the pressure-resistant container 130 for storage and is passed into the first plunger pump 140, and then control the fourth control valve 192 to allow the first plunger pump 140 to inject the carbon dioxide fluid through the first back pressure control valve 180. After the preheater 210 and the preheater 220 are adjusted to the preset pressure and temperature, the gas-liquid mixed fluid is uniformly introduced into each displacement hole 312 of the pad 310 at one end, and the gas-liquid mixed fluid in each displacement hole 312 of the pad 310 at the other end is uniformly discharged and transported to the gas-liquid separation device 420 for gas-liquid separation using the second back pressure controller 410, and the volume of the gas phase of the gas-liquid separation is respectively detected using the gas metering device 430, and the liquid phase image of the gas-liquid separation is taken using the camera device 450 to identify and detect the volume of the liquid phase;

[0062] The carbon dioxide displacement fluid is adjusted to a preset temperature and pressure and then uniformly introduced into each displacement hole 312 of an end pad 310 according to the following formula:

[0063]

[0064] In the formula, k i is the number of each displacement hole 312 into which the displacement fluid is introduced, F i When it is 0, it means that the injection of the displacement fluid into the corresponding displacement hole 312 is stopped. i When it is 1, it means that the displacement fluid is injected into the corresponding displacement hole 312; I(k i ) is the resistivity of each displacement hole 312 at the projection of the 1 / 4 depth position inside the rock mass at one end of the core 500, i.e., the end where the fluid is injected (i.e., at K1-1, K2-1, K3-1, and K4-1); I is resistivity; S w The water saturation detected at the water saturation measurement points of each displacement hole 312 through which the displacement fluid is introduced at the projection of the 1 / 4 depth position inside the rock mass at one end of the core 500, i.e., the injection end of the fluid; b and n are parameters; when the resistivity of each displacement hole 312 through which the displacement fluid is introduced at the projection of the 1 / 4 depth position inside the rock mass at one end of the core 500, i.e., the injection end of the fluid, is equal, the displacement fluid is injected into each displacement hole 312 at the same time;

[0065] The gas-liquid mixed fluid in each displacement hole 312 of the other end pad 310 is uniformly discharged according to the following formula to perform gas-liquid separation:

[0066]

[0067] In the formula, k j is the number of each displacement hole 312 for discharging the gas-liquid mixed fluid, F j When it is 0, it means that the gas-liquid mixed fluid is stopped from being discharged from the corresponding displacement hole 312, F j When it is 1, it means that the gas-liquid mixed fluid is discharged from the corresponding displacement hole 312; I(k j ) is the water saturation detected at the water saturation measurement points of each displacement hole 312 for discharging the gas-liquid mixed fluid at the projection of the 1 / 4 depth position inside the rock mass at the other end of the core 500, i.e., the fluid discharging end (i.e., K1-2, K2-2, K3-2, and K4-2); when the resistivity of each displacement hole 312 for discharging the gas-liquid mixed fluid at the projection of the 1 / 4 depth position inside the rock mass at the other end of the core 500, i.e., the fluid discharging end, is equal, the gas-liquid mixed fluid is discharged from each displacement hole 312 at the same time;

[0068] Step 4: Correct and calculate the injection amount of the displacement fluid and the gas phase output and liquid phase output of the gas-liquid separation to obtain the final injection amount of the displacement fluid, the cumulative gas phase output and the cumulative water phase output.

[0069] The following formula is used to correct the displacement fluid injection amount and calculate the final displacement fluid injection amount:

[0070]

[0071] In the formula, p inj is the injection pressure of the first plunger pump 140 for injecting the displacement fluid into each displacement hole 312; p1 is the final pressure when the displacement fluid is injected into each displacement hole 312; ΔV pump V is the cumulative change in the volume of the displacement fluid in the first plunger pump 140 during the injection of the displacement fluid; u (dead) is the volume of the pipeline between the first plunger pump 140 and each displacement hole 312 into which the displacement fluid is injected; Z inj is the compressibility of the fluid in the first plunger pump 140; Z1 is the compressibility of the fluid in the pipeline between the first plunger pump 140 and each displacement hole 312 into which the displacement fluid is injected; T inj is the temperature of the fluid in the first plunger pump 140; T1 is the temperature of the fluid in the pipeline between the first plunger pump 140 and each displacement hole 312 into which the displacement fluid is injected.

[0072] The gas phase output of gas-liquid separation is corrected and calculated according to the following formula to obtain the cumulative gas phase output:

[0073] Pro(water)=V water -V u (dead)-V d (dead);

[0074] Where V water V is the liquid production obtained by detecting the volume of the liquid phase in gas-liquid separation under atmospheric pressure; u (dead) is the volume of the pipeline between the first plunger pump 140 and each displacement hole 312 into which the displacement fluid is injected; V d (dead) is the volume of the pipeline between each displacement hole 312 for discharging the gas-liquid mixed fluid and the second back pressure controller 410;

[0075] The cumulative output of the water phase is calculated by correcting the liquid phase output of gas-liquid separation according to the following formula:

[0076]

[0077] Where V gas It is the gas production obtained by detecting the volume of the gas phase of gas-liquid separation under atmospheric pressure; p0 is the atmospheric pressure; p2 is the pressure in the pipeline between each displacement hole 312 for discharging the gas-liquid mixed fluid and the second back pressure controller 410; Z0 is the compressibility of the fluid under atmospheric pressure; Z2 is the compressibility of the fluid in the pipeline between each displacement hole 312 for discharging the gas-liquid mixed fluid and the second back pressure controller 410; T0 is the temperature of the fluid under atmospheric pressure; T2 is the temperature of the fluid in the pipeline between each displacement hole 312 for discharging the gas-liquid mixed fluid and the second back pressure controller 410.

[0078] The displacement perturbation simulation device and method provided in the embodiment of the present application provide a fluid injection system 100 to sequentially pressurize and preheat water and displacement fluid through a fluid injection pipe 200 and then inject them into a core 500 clamped by a core clamping system 300 for water saturation and displacement operations, and adjust the gas-liquid fluid discharged from the core 500 to a preset pressure through a fluid discharge pipe 250 and discharge it to a back pressure control monitoring metering system 400 for gas-liquid separation, and respectively detect the volume, temperature and pressure of the gas phase and liquid phase after gas-liquid separation, and then calculate the final injection amount of the displacement fluid, the cumulative output of the gas phase and the cumulative output of the water phase, so that high-temperature, high-pressure and large-flow displacement injection tests of large-size cores can be carried out to explore the physical process of gas oil displacement and gas displacement in deep reservoirs; wherein the fluid injection The injection system 100 can provide a stable power source for high-pressure fluid injection through the gas booster 120, the pressure-resistant container 130 and the first plunger pump 140, and achieve the goal of large-flow stable injection, and realize the temperature control of the displacement fluid through the refrigeration water bath device 150; the core clamping system 300 can realize the uniform injection and discharge of displacement fluid in different areas by setting multiple displacement areas 311 on the two end pads 310, each displacement area 311 includes a displacement hole 312 arranged on the end pad 310, an annular displacement channel 313 arranged radially and spaced along the displacement hole 312 and sleeved on the outside of the displacement hole 312, and six radial displacement channels 314 extending radially along the displacement hole 312, so as to simulate the displacement of actual reservoir perforation. The back pressure control monitoring metering system 400 realizes the continuous and stable metering of large-flow fluid by combining the visual metering method with the pump suction method by using the camera device 450 and the second plunger pump 440. The displacement and replacement disturbance simulation device provided in the embodiment of the present application has the advantages of simple structure, reliable design, and high detection accuracy, and can simulate high-temperature and high-pressure displacement conditions of large-sized cores in deep reservoirs.

[0079] The core clamping system 300 includes three intermediate pipes 320, and the two ends of the intermediate pipes 320 are respectively connected to the fluid injection pipe 200 and the fluid discharge pipe 250 through three-way interfaces. The intermediate pipes 320 are provided with a fifth control valve 330, a differential pressure gauge 340 and a sixth control valve 350. The differential pressure gauge 340 on the intermediate pipe 320 can be used to detect the pressure difference between the displacement holes 312 on the two end pads 310 connecting the fluid injection pipe 200 and the fluid discharge pipe 250 to evaluate the displacement operation.

[0080] The displacement perturbation simulation method provided in the embodiment of the present application injects water into the core 500 to saturate it with water, then calculates the conductivity after detecting the water saturation through the water saturation measurement point installed at the preset position in the core 500, and controls the fluid injection system 100 according to the conductivity at the preset position in the core 500, injects the displacement fluid evenly into the core 500 for displacement, and then evenly discharges the gas-liquid mixed fluid for gas-liquid separation, and detects the volume, temperature and pressure of the gas phase and liquid phase after the gas-liquid separation, and then performs correction calculations, eliminates the error of the residual fluid in the pipeline, and obtains the accurate final injection amount of the displacement fluid, the cumulative output of the gas phase and the cumulative output of the water phase to measure the displacement efficiency, so as to accurately carry out high-temperature, high-pressure and large-flow displacement injection tests of large-size cores.

[0081] In other optional embodiments, such as Figure 5 As shown, the displacement perturbation simulation system can also include only one fluid injection system 100, which includes a gas cylinder 110, a gas booster 120, a pressure container 130 and a first plunger pump 140 connected in sequence through pipelines, and the fluid injection system 100 includes a refrigerated water bath device 150 and a piston container 160 connected to the outlet of the first plunger pump 140 through a pipeline provided with a container control valve 170.

[0082] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A displacement perturbation simulation system, characterized in that: include: at least one fluid injection system, the fluid injection system comprising a gas cylinder, a gas booster, a pressure-resistant container and a first plunger pump connected in sequence through a pipeline; A fluid injection pipe, connected to the first plunger pump of each of the fluid injection systems, and the fluid injection pipe is provided with a first back pressure controller, a preheater and a first pressure sensor in sequence; A core clamping system, comprising two end pads for pressing and clamping both ends of a core, wherein the end pads are provided with a plurality of displacement areas, each of the displacement areas comprising a displacement hole provided in the end pad, a plurality of annular displacement channels sleeved outside the displacement hole, and a plurality of radial displacement channels extending radially along the displacement hole, each of the radial displacement channels being connected with the displacement hole and each corresponding annular displacement channel; the fluid injection pipe is connected with each of the displacement holes of the end pads through a pipeline provided with a first connecting valve; a fluid discharge pipe, connected to each of the displacement holes of the other end pad through a pipeline provided with a second connecting valve, and a second pressure sensor is provided on the fluid discharge pipe; The back pressure control monitoring and metering system comprises a second back pressure controller connected to the fluid discharge pipe, a gas-liquid separation device connected to the second back pressure controller, a gas metering device and a second plunger pump respectively connected to the gas-liquid separation device, and a camera device for collecting liquid surface images in the gas-liquid separation device, wherein the gas metering device is connected to a gas component detection device.

2. The displacement perturbation simulation system according to claim 1, characterized in that: At least one of the fluid injection systems includes a refrigerated water bath device, which is used to adjust the temperature of the corresponding pressure container and the first plunger pump to 0-25 degrees.

3. The displacement perturbation simulation system according to claim 1, characterized in that: At least one of the fluid injection systems comprises a piston container, and the piston container is connected to the outlet of the corresponding first piston pump through a pipeline provided with a container control valve.

4. The displacement perturbation simulation system according to claim 1, characterized in that: The pipeline between the gas cylinder and the gas booster is provided with a first control valve, and / or the pipeline between the gas booster and the pressure-resistant container is provided with a second control valve.

5. The displacement perturbation simulation system according to claim 1, characterized in that: The pipeline connected to the inlet of the first plunger pump is provided with a third control valve, and / or the pipeline connected to the outlet of the first plunger pump is provided with a fourth control valve.

6. The displacement perturbation simulation system according to claim 1, characterized in that: The core clamping system further comprises at least one intermediate tube, the two ends of which are respectively connected to the fluid injection tube and the fluid discharge tube, and the intermediate tube is provided with a fifth control valve, a differential pressure gauge and a sixth control valve.

7. A displacement perturbation simulation method, characterized in that: It includes the following steps: The two end pads are respectively pressed against the two ends of the core and then clamped and fixed, wherein the end pads are provided with a plurality of displacement areas, each of which includes a displacement hole provided on the end pad, a plurality of annular displacement channels sleeved outside the displacement hole, and a plurality of radial displacement channels extending radially along the displacement hole, and each of the radial displacement channels is connected with the displacement hole and each corresponding annular displacement channel; After adjusting the water to a preset temperature and pressure, pass the water into each of the displacement holes of the end pad to saturate the core with water; Using a first plunger pump to adjust the displacement fluid to a preset pressure and then evenly pass it into each displacement hole of one end pad, and evenly discharge the gas-liquid mixed fluid in each displacement hole of the other end pad and then transport it to the second back pressure controller for gas-liquid separation, and respectively detect the volume of the gas phase and liquid phase of the gas-liquid separation; The injection amount of the displacement fluid and the gas phase output and liquid phase output of the gas-liquid separation are respectively corrected and calculated to obtain the final injection amount of the displacement fluid, the cumulative output of the gas phase and the cumulative output of the water phase.

8. The displacement perturbation simulation method according to claim 7, characterized in that: After adjusting the displacement fluid to the preset temperature and pressure, the displacement fluid is uniformly introduced into each displacement hole of the end pad according to the following formula: In the formula, k i is the number of each displacement hole into which the displacement fluid is introduced, and F i When it is 0, it means that the injection of displacement fluid into the corresponding displacement hole is stopped. i When it is 1, it means that the displacement fluid is injected into the corresponding displacement hole, and the injection and stop of the displacement fluid in each displacement hole are controlled by a valve; I(k i ) is the corresponding resistivity of each of the displacement holes at the 1 / 4 depth projection inside the end surface of the core fluid injection end; And / or, the gas-liquid mixed fluid in each displacement hole of the other end pad is uniformly discharged according to the following formula to perform gas-liquid separation: In the formula, k j is the number of each displacement hole for discharging the gas-liquid mixed fluid, F j When it is 0, it means that the gas-liquid mixed fluid is stopped from being discharged from the corresponding displacement hole, F j When it is 1, it means that the gas-liquid mixed fluid is discharged from the corresponding displacement hole, and the discharge and stop of the gas-liquid mixed fluid in each displacement hole are controlled by a valve; I(k j ) is the corresponding resistivity of each of the displacement holes at the 1 / 4 depth projection inside the end face of the core fluid discharge end.

9. The displacement perturbation simulation method according to claim 7, characterized in that: The following formula is used to correct the displacement fluid injection amount and calculate the final displacement fluid injection amount: In the formula, p inj is the injection pressure of the first plunger pump for injecting the displacement fluid into each of the displacement holes; p1 is the final pressure when the displacement fluid is injected into each of the displacement holes; ΔV pump V is the cumulative change in the volume of the displacement fluid in the first plunger pump during the process of injecting the displacement fluid into each of the displacement holes; u (dead) is the volume of the pipeline between the first plunger pump and each of the displacement holes into which the displacement fluid is injected; Z inj is the compressibility of the fluid in the first plunger pump; Z1 is the compressibility of the fluid in the pipeline between the first plunger pump and each of the displacement holes into which the displacement fluid is injected; T inj is the temperature of the fluid in the first plunger pump; T1 is the temperature of the fluid in the pipeline between the first plunger pump and each of the displacement holes into which the displacement fluid is injected.

10. The displacement perturbation simulation method according to claim 8, characterized in that: The gas phase output of gas-liquid separation is corrected and calculated according to the following formula to obtain the cumulative gas phase output: Pro(water)=V water -V u (dead)-V d (dead); Where V water V is the liquid production obtained by detecting the volume of the liquid phase in gas-liquid separation under atmospheric pressure; u (dead) is the volume of the pipeline between the first plunger pump and each of the displacement holes into which the displacement fluid is injected; V d (dead) is the volume of the pipeline between each displacement hole for discharging the gas-liquid mixed fluid and the second back pressure controller; The cumulative output of the water phase is calculated by correcting the liquid phase output of gas-liquid separation according to the following formula: Where V gas It is the gas production obtained by detecting the volume of the gas phase of gas-liquid separation under atmospheric pressure; p0 is the atmospheric pressure; p2 is the pressure in the pipeline between each of the displacement holes for discharging the gas-liquid mixed fluid and the second back pressure controller; Z0 is the compressibility of the fluid under atmospheric pressure; Z2 is the compressibility of the fluid in the pipeline between each of the displacement holes for discharging the gas-liquid mixed fluid and the second back pressure controller; T0 is the temperature of the fluid under atmospheric pressure; T2 is the temperature of the fluid in the pipeline between each of the displacement holes for discharging the gas-liquid mixed fluid and the second back pressure controller.

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