Horizontal well indoor seepage simulation test device and simulation test method

Abstract

The invention discloses a simulation test method for a simulation test device for a horizontal well seepage indoor. The seepage sand trough is a hollow cuboid without a cover. The baffle is divided into a control boundary box and a sand trough box along the length direction. A supply hole is arranged on the baffle. The sand trough box is filled with simulated formation materials. Micropore pressure sensors are buried in the simulated formation materials along radial and tangential directions. The control boundary box is provided with a liquid inlet, a plurality of overflow ports at different heights and scale lines, and is filled with simulated fluid. A regulating valve and a flow retarder are arranged at the liquid inlet. Each overflow port is controlled by a valve separately. A constant current and constant pressure pump supplies fluid to the simulated formation. A mounting hole is arranged on the side wall of the sand trough box opposite to the baffle. A flange is installed in the mounting hole. A horizontal screen pipe and a hose are butt-jointed through the flange. A freely movable nylon tube is inserted into the horizontal screen pipe and the hose. The nylon tube outlet extends through the hose inlet to be connected with a diaphragm pump. A flow sensor is installed on the nylon tube close to the diaphragm pump. The horizontal screen pipe is buried in the simulated formation material.

Description

Technical Field

[0001] The present invention belongs to the field of fluid seepage research, and in particular relates to a simulation test method of a horizontal well seepage indoor simulation test device capable of accurately simulating the seepage law and three-dimensional pore pressure characteristics of horizontal wells for exploiting underground oil, gas, water and other fluids. Background Art

[0002] Because the seepage law and three-dimensional pore pressure characteristics of underground oil, gas, water and other fluids in horizontal wells are completely different from those in vertical wells, and analytical methods can only solve relatively simple seepage problems, while slightly more complex seepage problems can only be solved by physical simulation or numerical simulation. Numerical simulation is abstracted from physical phenomena and is not intuitive, so physical simulation is more reliable and easier to master than numerical simulation.

[0003] In recent years, numerical methods have been widely used in horizontal well seepage and production theory and have solved many problems that are difficult to solve with analytical methods. However, physical simulation experiments still have their own unique characteristics in solving problems. Based on similarity theory, similar models are used to reproduce the seepage dynamics and response processes of underground oil, gas and water during horizontal well production. Physical model experiments use similar variables and parameters to simulate the seepage law, which has the dual characteristics of analysis and experiment. Its biggest feature is that the seepage phenomenon and law can be directly observed from the experiment. Compared with prototype experiments, firstly, the geometric size of the seepage zone can be reduced to adapt to the scale of the laboratory, which is convenient for studying the distribution characteristics of seepage from the overall rather than the local perspective; secondly, the evolution speed of seepage can be accelerated. In the model, it only takes a few seconds or minutes to simulate the seepage process of several days or even decades, which can save a lot of time. Summary of the invention

[0004] The first object of the present invention is to provide a simulation experiment method of a horizontal well seepage indoor simulation test device which has a simple structure, stable and reliable operation and can accurately simulate the horizontal well to exploit underground reservoir fluid.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A horizontal well indoor seepage simulation test device comprises a seepage sand trough, a horizontal well miniature model, a measuring device and a water circulation device. The spatial structure of the seepage sand trough is a hollow cuboid without a cover. The seepage sand trough is divided into a control boundary box and a sand trough box by a rigid partition along the length direction of the seepage sand trough. Seepage supply holes are evenly arranged on the rigid partition. The sand trough box is filled with simulated formation materials. The micropore pressure sensor of the measuring device is buried in the simulated formation materials along the radial and tangential directions of the horizontal well model. The control boundary box is filled with simulated liquid fluid. The side wall of the control boundary box is provided with a liquid inlet, a plurality of overflow ports at different heights and a scale. Each overflow port is separately equipped with a valve. The water circulation device comprises a constant flow and constant pressure pump and a flow regulating valve. The constant flow and constant pressure pump is connected to the control boundary box through a pipeline. The liquid inlet of the controllable boundary box is connected to the simulated formation to supply liquid fluid, a flow regulating valve is arranged on the pipeline, a mounting hole is opened on the side wall of the sand tank box opposite to the rigid partition, a flange is installed on the mounting hole, the horizontal well miniature model includes a test horizontal screen pipe and a hose, the inlet end of the horizontal screen pipe and the outlet end of the hose are connected by a flange, a freely movable nylon tube is inserted into the horizontal screen pipe and the hose to simulate the position of the pump in the horizontal well exploitation, the outlet end of the nylon tube extends through the inlet end of the hose to be connected to the diaphragm pump, the flow sensor of the measuring device is installed on the nylon tube near the diaphragm pump, the horizontal screen pipe is buried in the simulated formation material, the measuring device also includes a multi-channel data acquisition terminal, the micropore pressure sensor and the flow sensor are connected to the multi-channel data acquisition terminal signal.

[0007] A scale is attached to the inner side wall of the sand tank box from the bottom plate to the top.

[0008] Two layers of gauze are covered on the partition side of the sand tank box, and the pore size of the sand mesh is about 1 / 2-2 / 3 of the median particle size of the simulated formation material.

[0009] The installation hole is 30-40 cm away from the bottom plate of the sand tank box.

[0010] A simulation test method using the technical solution of the horizontal well indoor seepage simulation test device as described in any one of the above items comprises the following steps:

[0011] A. Select simulated bulk granular materials that are consistent with the actual horizontal well mining formation particle size distribution curve, porosity, mud content, permeability and other geotechnical physical and mechanical parameters, wash and screen the simulated formation materials, remove impurities as much as possible, mix them evenly according to the proportion, and then load them into the sand tank box and compact them;

[0012] B. Select simulated liquid fluid with the same physical property parameters of viscosity and viscosity coefficient as those of the actual horizontal well production formation fluid for standby;

[0013] C. Layered filling of simulated formation materials: before filling the materials, apply silica gel on the four side walls inside the seepage sand trough box, and then cover the simulated formation materials for the test on them to form a thin sand layer on the side walls to eliminate the influence of the side wall effect of the sand trough box on the simulation test; then, the simulated formation materials are layered and compacted according to the scale lines set on the inside of the sand trough box to ensure the thickness of the simulated formation materials each time. During the filling process of the simulated formation materials, the method of layered compaction and bulk density control is adopted to make the simulated formation as uniform as possible to meet the test requirements of homogeneity and isotropy; at the same time, the micro-hole pressure sensors are buried in the radial and tangential directions of the horizontal well model at different positions in the simulated formation material formation; when the simulated formation reaches the installation position of the circular hole, the horizontal well miniature model is installed, and after the installation is completed, the filling and compaction of the simulated formation materials of the layer are continued;

[0014] D. When the simulated formation material is loaded to the installation circular hole position, the installation of the horizontal well miniature model is carried out: the horizontal screen of the horizontal well miniature model is placed in the simulated formation of the sand trough box to simulate the mining section of the horizontal well, and the hose is sealed and connected to the horizontal screen through the installation circular hole on the side wall of the sand trough box through a flange. The transparent hose is placed outside the sand trough box to simulate the horizontal well process section; a smaller-diameter nylon tube is built into the transparent hose, and the outlet section of the nylon tube is connected to an adjustable-range diaphragm pump. The pressure reduction amplitude of horizontal well mining is simulated by adjusting the flow rate of the pump. The nylon tube can move freely in the horizontal screen and the transparent hose to simulate the position of the pump in horizontal well mining. A high-precision flow sensor is installed on the nylon tube close to the diaphragm pump to measure and collect the fluid extraction flow rate in the test.

[0015] E. After the installation of the horizontal well miniature model is completed, continue to simulate the filling and compaction of the formation material. After the simulated formation where the horizontal screen is located is filled and compacted in layers, use a constant pressure and constant speed horizontal flow pump to slowly pump the simulated fluid into the control boundary box, so that the fluid slowly enters the control boundary box. The fluid pumping height should be about 2-3 cm lower than the compacted simulated formation material, and wait for the fluid to slowly pass through the rigid partition to continuously supply the compacted simulated formation material with fluid to make it saturated. At the same time, turn on the diaphragm pump to ensure that the bubbles in the pores of the simulated formation material are discharged to prevent affecting the test results. At the same time, turn on the data acquisition instrument connected to the micro pore pressure sensor to keep it in working condition, and keep the fluid head pressure in the control boundary box stable. Observe continuously Observe the fluctuation of the pressure head of the micro-pore pressure sensors at different positions in the seepage sand tank box reflected by the data acquisition instrument. When the stable state required by the test is reached, the data acquisition instrument will display a series of different straight lines, and at this time, the pressure head values ​​of all the micro-pore pressure sensors at the same horizontal plane are equal, that is, the connection line of the pressure head values ​​of the micro-pore pressure sensors on the same horizontal plane is a horizontal straight line. At this time, it is considered that the simulated formation has reached a saturated state, and the horizontal well miniature model is already in an ideal homogeneous formation. After the fluid saturation operation of the simulated formation material is completed, the surface of the compacted simulated formation material is completely scraped and then the next simulated formation material is evenly poured in to ensure that the two simulated formation materials are fully fitted to avoid stratification.

[0016] F. Continue to simulate the filling of formation materials, continue to weigh, continue to compact, and verify fluid saturation. Follow this method until the test plan is designed to simulate the formation thickness.

[0017] The arrangement positions and quantity of the micro pore pressure sensors are based on the measurement accuracy required by the experimental design.

[0018] The method for controlling the bulk density of simulated formation materials adopts the experimental simulated formation material density measured in the laboratory for control, calculates the mass M of simulated formation materials required for each layer filled in the sand trough according to this density, and weighs it multiple times using a platform scale. When the weight of the simulated formation materials poured into the sand trough reaches the calculated value, the filling of the simulated formation materials is stopped, and the simulated formation materials are compacted to a thickness that meets the scale line requirements.

[0019] The simulated formation material may include one or more of river sand, quartz sand, and ceramsite with different particle size specifications.

[0020] Silt or clay may be added to the simulated formation material to simulate the mud content and low permeability characteristics of the actual mining formation.

[0021] The simulated liquid fluid can be used with tap water or distilled water to simulate the horizontal well exploitation of groundwater resources, and can be used to simulate the underground exploitation of saline-alkali strata and highly mineralized salt water by adding salt.

[0022] Beneficial effects of the present invention: The test device and test method of the present invention can prepare and load simulated formations with different particle size specifications, porosity, permeability and other rock and soil physical and mechanical parameters according to factors such as horizontal well mining formation geological parameters, fluid characteristics, and well formation structure. Through the horizontal well indoor simulation test device, physical model tests of horizontal well mining seepage characteristics under conditions such as different formation mechanical parameters, different screen specifications, different horizontal section burial depths and different pump positions (horizontal section, deflection process section) are carried out. During the test, micropore pressure and flow sensors are used to collect and measure data, analyze the seepage laws, three-dimensional pore pressure distribution characteristics and mining influencing factors in the horizontal well mining process, and provide calculation parameters and optimization design for actual mining formations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the indoor seepage simulation test device for horizontal wells.

[0024] Figure 2 It is a schematic diagram of the structure of the seepage sand trough box.

[0025] Figure 3 Schematic diagram of the radial (axial) layout of micro pore pressure sensors.

[0026] Figure 4 Schematic diagram of tangential (vertical) layout of micro pore pressure sensors DETAILED DESCRIPTION

[0027] like Figures 1 to 4 As shown, a horizontal well indoor seepage simulation test device of the present invention includes a seepage sand trough, a horizontal well miniature model, a measuring device and a water circulation device.

[0028] The spatial structure of the seepage sand trough 1 is a hollow rectangular parallelepiped without a cover. The seepage sand trough is divided into a control boundary box 12 and a sand trough box 13 by a rigid partition 11 along the length direction of the seepage sand trough. Seepage supply holes are evenly arranged on the rigid partition 11. In order to prevent the simulated formation material from entering the control boundary box through the partition, two layers of gauze are covered on the partition side of the sand trough box. The pore size of the sand mesh is about 1 / 2-2 / 3 of the median particle size of the simulated formation material. The partition has a There is a unidirectional infiltration effect. The partition only allows the water flow in the control boundary box to slowly infiltrate into the simulated stratum soil 14 of the sand trough box, while preventing the simulated stratum soil of the sand trough box from entering the control boundary box. The infiltration water volume is precisely controlled and adjusted by the partition, and the fixed head position in the control boundary box changes less, which simulates the recharge relationship of the actual stratum more realistically, and the test data is more real and accurate. The length, width, and height of the sand trough box and the control boundary box meet the geometric similarity requirements of the physical model test similarity theory. In this embodiment, The length is about 5 meters, the width is about 2.5 meters, and the height is about 1.5 meters. The rigid partition is 200-400mm away from the control boundary box. The inner side of the sand trough box is marked with scale lines (the smallest scale unit is cm) from the bottom plate to the top. The bottom plate boundary and the side plate boundary can be regarded as isolation boundaries. The sand trough box 13 is filled with simulated formation materials with different particle size specifications, porosity, permeability and other rock and soil physical and mechanical parameters prepared according to the test plan; a water inlet 121 is opened on one side wall of the control boundary box, and the relative A plurality of overflow ports 122 of different heights and a scale are provided on the other side wall, which are used to store and maintain a certain head height (i.e., the fluid pumping height should be about 2-3 cm lower than the compacted simulated formation material each time) of the simulated liquid fluid for the test, and to continuously and stably supply the simulated formation in the sand trough box through the rigid partition. A 90 mm diameter hole 131 is provided on the side wall of the sand trough box relative to the rigid partition in the axial direction at a height of 30-40 cm from the bottom, which is used to install and connect the horizontal well miniature model.

[0029] The measuring device comprises a micro-pore pressure sensor, a flow sensor and the multi-channel data acquisition terminal 2, and the micro-pore pressure sensor and the flow sensor are connected to the multi-channel data acquisition terminal for signal connection. Figure 3 and Figure 4 As shown, the micro-pore pressure sensor 20 of the measuring device is buried in the radial and tangential directions of the horizontal well model in the simulated formation material, which is used to collect and measure the pore pressure of the radial and tangential monitoring points of the horizontal well during the physical simulation test, and analyze the three-dimensional pore pressure distribution characteristics of the formation around the well during the horizontal well production process. The layout position and number of the micro-pore pressure sensors are based on the measurement accuracy required by the experimental design.

[0030] The horizontal well miniature model is mainly composed of a horizontal screen tube 21 (which can be a plastic tube, a stainless steel tube or an industrial screen tube) and a transparent hose 22. A flange is installed on the mounting circular hole. The inlet end of the horizontal screen tube is sealed and connected to one end of the flange. The other end of the flange is connected to one end of a switch valve. The other end of the switch valve is connected to the outlet end of the hose. The horizontal screen tube near the hose is placed in a simulated stratum of a sand tank box to simulate the mining section of the horizontal well. The transparent hose is placed outside the seepage sand tank to simulate the process section of the horizontal well. A smaller caliber nylon tube 23 is built into the transparent hose. A high-precision flow sensor is installed on the nylon tube near the diaphragm pump to measure and collect the fluid extraction flow in the test. The nylon tube 23 can move freely in the horizontal screen tube and the transparent hose to simulate the position of the pump in the horizontal well mining. The outlet section of the nylon tube is connected to an adjustable range diaphragm pump. The pressure reduction amplitude of the horizontal well mining is simulated by adjusting the flow of the pump, so as to achieve the purpose of matching the seepage velocity with the mining velocity and optimizing the mining.

[0031] The water circulation device includes a constant flow and constant pressure pump 41, a flow regulating valve and a water inlet retarder. The constant flow and constant pressure pump is connected to the liquid inlet of the control boundary box through a pipeline and supplies liquid fluid to the simulated formation. The flow regulating valve and the water inlet retarder are arranged on the pipeline at the liquid inlet of the control boundary box. The flow regulating valve is controlled by the computer of the test device, and each overflow port is individually controlled by a valve to ensure that the water head in the control boundary box is stably and continuously supplied to the simulated formation in the sand tank box on the other side of the partition during the test; the head pressure of the horizontal well seepage test is controlled by adjusting the working pressure of the constant pressure and constant speed horizontal flow pump to simulate the pressure difference of horizontal well exploitation.

[0032] The sand trough box and the control boundary box can be made of organic glass, steel plate, etc. (the thickness meets the strength required by the test requirements), and have a certain rigidity to avoid the influence of elastic release energy caused by box deformation on the test data during the test.

[0033] The specific steps of the simulation experiment method of the present invention are as follows:

[0034] A. Select simulated bulk granular materials that are consistent with the actual horizontal well mining formation particle size distribution curve, porosity, mud content, permeability and other geotechnical physical and mechanical parameters, wash and screen the simulated formation materials, try to remove impurities, and fully mix them according to a certain ratio (adjust permeability, porosity, mud content and other parameters) for use; Figure 2 shown.

[0035] B. Select a simulated liquid fluid with the same physical property parameters as the viscosity and viscosity coefficient of the actual horizontal well production formation fluid for standby.

[0036] C. Layered filling and compaction of simulated formation materials and verification of fluid saturation: Before loading the materials, apply silica gel to the four side walls inside the seepage sand trough box, and then cover the experimental simulated formation materials on them to form a thin sand layer on the side walls to eliminate the influence of the side wall effect of the seepage sand trough box on the simulation test; then, fill and compact the simulated formation materials according to the scale lines set on the inside of the sand trough box to ensure the thickness of the simulated formation materials each time; in the step of filling the simulated formation materials, according to the test plan, at different positions in the simulated formation materials in the seepage sand trough (to reflect the pore pressure fluctuation of the underground fluid in the entire simulated formation as much as possible, and the layout position and quantity shall be based on the measurement accuracy required by the test design) along the radial and tangential directions of the horizontal well model. In the direction, the buried micro-pore pressure sensor is used to collect and analyze the three-dimensional pore pressure distribution characteristics of the formation around the well during the horizontal well mining process; in the process of filling the simulated formation material, the method of layered compaction and bulk density control is adopted to make the simulated formation as uniform as possible to meet the test requirements of homogeneity and isotropy; the bulk density control method of the simulated formation material adopts the experimental simulated formation material density measured in the laboratory for control, and calculates the mass M of the simulated formation material required to fill each layer (100mm) in the sand trough according to this density, and weighs it several times by a platform scale. After the weight of the simulated formation material poured into the sand trough reaches the calculated value, the filling of the simulated formation material is stopped, and it is compacted to the thickness to the scale line requirement (such as 100mm);

[0037] D. When the simulated formation material is loaded to the installation circular hole position, the installation of the horizontal well miniature model is carried out: the horizontal screen tube of the horizontal well miniature model is placed in the simulated formation of the sand trough box to simulate the mining section of the horizontal well, and the hose and the horizontal screen tube are sealed and connected through the installation circular hole on the side wall of the sand trough box through the flange plate, and the transparent hose is placed outside the sand trough box to simulate the horizontal well process section; a smaller caliber nylon tube is built into the transparent hose, and the outlet section of the nylon hose is connected to an adjustable range diaphragm pump, and the pressure reduction amplitude of horizontal well mining is simulated by adjusting the flow of the pump, that is, the liquid level in the transparent hose outside the sand trough box is controlled by adjusting the flow of the pump, forming different water level differences between the outside of the sand trough and the control boundary to generate hydraulic gradient; the nylon tube can move freely in the horizontal screen tube and the transparent hose, which is used to simulate the position of the pump in horizontal well mining, and a high-precision flow sensor is installed on the nylon tube close to the diaphragm pump to measure and collect the fluid extraction flow in the test.

[0038] E. After the installation of the horizontal well miniature model is completed, continue to simulate the filling and compaction of the formation material. After the simulated formation where the horizontal screen is located is filled and compacted in layers, use a constant pressure and constant speed horizontal flow pump to slowly pump the simulated fluid into the control boundary box, so that the fluid slowly enters the control boundary box. The fluid pumping height should be about 2-3 cm lower than the compacted simulated formation material, and wait for the fluid to slowly pass through the rigid partition to continuously supply the compacted simulated formation material with fluid to make it saturated. At the same time, turn on the diaphragm pump to ensure that the bubbles in the pores of the simulated formation material are discharged to prevent affecting the test results. At the same time, turn on the data acquisition instrument connected to the micro pore pressure sensor to keep it in working condition, and keep the fluid head pressure in the control boundary box stable. Observe continuously Observe the fluctuation of the pressure head of the micro-pore pressure sensors at different positions in the seepage sand tank box reflected by the data acquisition instrument. When the stable state required by the test is reached, the data acquisition instrument will display a series of different straight lines, and at this time, the pressure head values ​​of all the micro-pore pressure sensors at the same horizontal plane are equal, that is, the connection line of the pressure head values ​​of the micro-pore pressure sensors on the same horizontal plane is a horizontal straight line. At this time, it is considered that the simulated formation has reached a saturated state, and the horizontal well miniature model is already in an ideal homogeneous formation. After the fluid saturation operation of the simulated formation material is completed, the surface of the compacted simulated formation material is completely scraped and then the next simulated formation material is evenly poured in to ensure that the two simulated formation materials are fully fitted to avoid stratification.

[0039] F. Continue to simulate the filling of formation materials, continue to weigh, continue to compact, and verify fluid saturation. Follow this method until the test plan is designed to simulate the formation thickness.

[0040] The simulated formation material is a bulk particle accumulation body that meets a certain particle size distribution rule, and the accumulation body is a pore structure.

[0041] The simulated formation material may include one or more of river sand, quartz sand, and expanded clay with different particle size specifications; a certain proportion of silt or clay may be added to the simulated formation material to simulate the mud content and low permeability characteristics of the actual mining formation.

[0042] The simulated liquid fluid can use tap water and distilled water to simulate the horizontal well exploitation of groundwater resources, and can be used to simulate the underground exploitation of saline-alkali strata and highly mineralized salt water by adding salt; industrial waste oil can be used to simulate the exploitation of underground petroleum; a mixture of a certain proportion of water and industrial waste oil can be used to simulate the in-situ horizontal well drainage pollution remediation of organic hydrocarbons in the soil.

[0043] The number and position of the micro pore pressure sensors and the number of channels of the data acquisition instrument can be changed according to the measurement accuracy required by the test design. The micro pore pressure sensor has the characteristics of high accuracy (0.1% FS), small size (2.5mm*3.5mm), and high stability; the data acquisition instrument has 16 channels or 32 channels. The arrangement and installation of the micro pore pressure and flow sensors are to obtain the seepage field and pore pressure fluctuation of the formation fluid around the horizontal well during the horizontal well mining process.

[0044] The permeability of the partition between the seepage sand trough box and the control boundary box can be adjusted by the porosity of the sand mesh covered thereon to simulate the recharge characteristics (strong, medium, weak) of the actual formation. The porosity is designed and calculated based on the permeability coefficient of the formation to be simulated.

[0045] The test device and test method of the present invention can prepare and load simulated formations with different particle size specifications, porosity, permeability and other rock and soil physical and mechanical parameters according to factors such as horizontal well mining formation geological parameters, fluid characteristics, and well formation structure. Through indoor simulation tests of horizontal wells, physical model tests of seepage characteristics of horizontal well mining under conditions such as different formation mechanical parameters, different screen specifications, different horizontal section burial depths, and different pump positions (horizontal section, deflection process section) are carried out. During the test, data is collected and measured through micropore pressure and flow sensors to analyze the seepage laws, three-dimensional pore pressure distribution characteristics and mining influencing factors in the horizontal well mining process, so as to provide calculation parameters and optimization design for actual mining formations.

Claims

1. A simulation test method for a horizontal well seepage indoor simulation test device, characterized in that: The simulation test device includes a seepage sand trough, a horizontal well miniature model, a measuring device and a water circulation device. The spatial structure of the seepage sand trough is a hollow rectangular parallelepiped without a cover. The seepage sand trough is divided into a control boundary box and a sand trough box by a rigid partition along the length direction of the seepage sand trough. Seepage supply holes are evenly arranged on the rigid partition. The sand trough box is filled with simulated formation materials. The micropore pressure sensor of the measuring device is buried in the simulated formation materials along the radial and tangential directions of the horizontal well model. The control boundary box is filled with simulated liquid fluid. The side wall of the control boundary box is provided with a liquid inlet, a plurality of overflow ports at different heights and a scale. A valve is separately installed at each overflow port. The water circulation device includes a constant flow and constant pressure pump and a flow regulating valve. The constant flow and constant pressure pump is connected to the liquid inlet of the control boundary box through a pipeline. A flow regulating valve is arranged on the pipeline for supplying liquid fluid to the simulated formation, a mounting hole is opened on the side wall of the sand tank box body opposite to the rigid partition, a flange is installed on the mounting hole, the horizontal well miniature model includes a horizontal screen pipe and a transparent hose, the inlet end of the horizontal screen pipe and the outlet end of the transparent hose are connected by a flange, a freely movable nylon tube is inserted into the horizontal screen pipe and the transparent hose to simulate the position of the pump in the horizontal well exploitation, the outlet end of the nylon tube extends through the inlet end of the transparent hose and is connected to an adjustable range diaphragm pump, a flow sensor of the measuring device is installed on the nylon tube close to the adjustable range diaphragm pump, the horizontal screen pipe is buried in the simulated formation material, the measuring device also includes a multi-channel data acquisition terminal, the micropore pressure sensor and the flow sensor are connected to the multi-channel data acquisition terminal signal; The simulation test method of the simulation test device comprises the steps of: A. Select simulated bulk granular materials that are consistent with the actual horizontal well mining formation particle size distribution curve, porosity, shale content, and permeability of geotechnical physical and mechanical parameters, wash and screen the simulated formation materials to remove impurities, mix them evenly according to the proportion, and then load them into the sand tank box and compact them; B. Selecting a simulated liquid fluid with the same fluid physical property parameters as the viscosity and viscosity coefficient of the actual horizontal well production formation fluid for standby; C. Layered filling of simulated formation materials: before loading the simulated formation materials, apply silica gel on the four side walls inside the sand trough box, and then cover the simulated formation materials for the test on them to form a thin sand layer on the side walls to eliminate the influence of the side wall effect of the sand trough box on the simulation test; then, the simulated formation materials are layered and compacted according to the scale lines set on the inside of the sand trough box to ensure the thickness of the simulated formation materials each time. During the filling process of the simulated formation materials, the method of layered compaction and bulk density control is adopted to make the simulated formation as uniform as possible to meet the test requirements of homogeneity and isotropy; at the same time, micro-hole pressure sensors are buried in different positions in the simulated formation materials along the radial and tangential directions of the horizontal well model; when the simulated formation materials reach the installation position of the circular hole, the horizontal well miniature model is installed. After the installation is completed, the layered simulated formation materials are continued to be filled and compacted; D. When the simulated formation material is loaded to the installation circular hole position, the installation of the horizontal well miniature model is carried out: the horizontal screen tube of the horizontal well miniature model is placed in the simulated formation of the sand trough box to simulate the mining section of the horizontal well, and the transparent hose is sealed and connected to the horizontal screen tube through the installation circular hole on the side wall of the sand trough box through the flange plate, and the transparent hose is placed outside the sand trough box to simulate the horizontal well process section; a smaller caliber nylon tube is built into the transparent hose, and the outlet end of the nylon tube is connected to an adjustable range diaphragm pump, and the pressure reduction amplitude of horizontal well mining is simulated by adjusting the flow of the adjustable range diaphragm pump. The nylon tube can move freely in the horizontal screen tube and the transparent hose to simulate the position of the pump in the horizontal well mining, and a high-precision flow sensor is installed on the nylon tube close to the adjustable range diaphragm pump to measure and collect the fluid extraction flow in the test; E. After the installation of the horizontal well miniature model is completed, continue to simulate the filling and compaction of the formation material. After the simulated formation where the horizontal screen is located is filled and compacted in layers, use a constant flow and constant pressure pump to slowly pump the simulated fluid into the control boundary box to allow the fluid to slowly enter the control boundary box. The fluid pumping height should be 3 cm lower than the compacted simulated formation material, and wait for the fluid to slowly pass through the rigid partition to continuously supply the compacted simulated formation material with fluid to make it saturated. At the same time, turn on the adjustable range diaphragm pump to ensure that the bubbles in the pores of the simulated formation material are discharged to prevent affecting the test results. At the same time, turn on the data acquisition instrument connected to the micropore pressure sensor to keep it in working condition, and keep the fluid head pressure in the control boundary box stable without interruption. Observe the fluctuation of the pressure head of the micro-hole pressure sensor at different positions in the sand tank box reflected by the data acquisition instrument. When the stable state required by the test is reached, the data acquisition instrument will display a series of different straight lines, and at this time, the pressure head values ​​of all the micro-hole pressure sensors at the same horizontal plane are equal, that is, the connecting line of the pressure head values ​​of the micro-hole pressure sensors on the same horizontal plane is a horizontal straight line. At this time, it is considered that the simulated formation has reached a saturated state, and the horizontal well miniature model is already in an ideal homogeneous formation. After the fluid saturation operation of the simulated formation material is completed, the surface of the compacted simulated formation material is completely scraped and then the simulated formation material is evenly poured in to ensure that the two simulated formation material fillings are completely fitted to avoid stratification. F. Continue to simulate the filling of formation materials, continue to weigh, continue to compact, and verify fluid saturation. Follow this method until the test plan is designed to simulate the formation thickness.

2. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: The inner side wall of the sand tank box is marked with scale lines from the bottom plate to the top.

3. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: Two layers of gauze are covered on the partition side of the sand tank box, and the pore size of the sand mesh is about 1 / 2-2 / 3 of the median particle size of the simulated formation material.

4. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: The installation hole is 30-40 cm away from the bottom plate of the sand tank box.

5. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: The arrangement positions and quantities of the micro-hole pressure sensors are based on the measurement accuracy required by the experimental design.

6. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: The method for controlling the bulk density of simulated formation materials adopts the experimental simulated formation material density measured in the laboratory for control, calculates the mass M of simulated formation materials required for each layer filled in the sand trough box according to this density, and weighs it multiple times using a platform scale. When the weight of the simulated formation materials poured into the sand trough box reaches the calculated value, the filling of the simulated formation materials is stopped and they are compacted to the thickness scale requirement.

7. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: The simulated formation material includes one or more of river sand, quartz sand and ceramsite with different particle size specifications.

8. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: Silt or clay may be added to the simulated formation material to simulate the mud content and low permeability characteristics of the actual mining formation.

9. The simulation test method of the horizontal well seepage indoor simulation test device according to claim 1, characterized in that: The simulated liquid fluid can be used with tap water or distilled water to simulate the horizontal well exploitation of groundwater resources, and can be used to simulate the underground exploitation of saline-alkali strata and highly mineralized salt water by adding salt.

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