Displacement device for gas injection and oil extraction indoor experiment for synchronous core fracture forming

Abstract

The utility model discloses a displacement device for a gas injection and oil extraction indoor experiment for synchronous core fracture forming, which comprises a horizontally placed core barrel, sealing covers arranged at two ends of the core barrel, a simulation injection pipe arranged on the sealing cover positioned at the front end, and a simulation extraction pipe arranged on the sealing cover positioned at the rear end, a confining pressure boosting pipe used for simulating formation pressure is arranged at the top of the middle of the rock core barrel, a sealing rubber sleeve is arranged in the rock core barrel, a simulation rock core is arranged in the sealing rubber sleeve, a plurality of fracture forming holes are formed in the side wall of the rock core barrel, a support is arranged on one sides of the fracture forming holes, and a fracture forming motor used for being in butt joint with the fracture forming holes is arranged on the support. According to the utility model, the outer wall of the rock core barrel is transformed, so that the rock core barrel can be matched with the fracture-forming motor which is placed on the bracket in advance, the rock core after displacement is finished is immediately subjected to simulated fracture-forming, the fracture-forming precision is high, the use and the operation are convenient and rapid, and the rock core fracture-forming device has guiding significance for indoor simulation of oil-gas field development.

Description

Technical Field

[0001] The utility model relates to the technical field of oil production engineering, in particular to a displacement device for indoor experiments of gas injection oil production with synchronous core fracture creation. Background Art

[0002] Gas injection is a method of increasing oilfield recovery by injecting gas (natural gas, carbon dioxide, nitrogen, or air) into the oil reservoir through an injection well to replenish and maintain reservoir energy. Common methods include top injection and area injection. The development trend of gas injection is to inject wet gas, liquefied gas, and carbon dioxide. This increases oil displacement power while creating miscible drive or improving oil flow properties, thereby enhancing recovery. Top injection is one of the gas injection methods. During oilfield development, gas is injected into the top of the oil reservoir to continuously replenish the reservoir's energy during production.

[0003] In indoor simulation experiments of gas injection for oil recovery, a high-pressure core displacement system (core experimental device) is usually used. The general core displacement system provides high-precision flow or high-precision constant high-pressure liquid or gas displacement, and is used in conjunction with laboratory instruments or devices that simulate different formation pressure conditions to study core permeability and improve crude oil recovery.

[0004] During simulation experiments, we sometimes need to further modify the core to study various different formation conditions. Common core modification methods include simulating fractures after creating fractures. However, the currently commonly used core displacement system has not been improved for core simulation fracture creation. The core must be removed before fracture creation. Utility Model Content

[0005] In view of the above-mentioned problems, the utility model provides an adjustable integrated heating and heat-insulating device for a wellhead Christmas tree in winter.

[0006] The technical solution of the utility model is:

[0007] A displacement device for indoor experiments in gas injection and oil production with synchronous core fracture creation, comprising a horizontally placed core barrel, sealing covers being provided at both ends of the core barrel, a simulated injection pipe being provided on one of the sealing covers located at the front end, a simulated production pipe being provided on the sealing cover located at the rear end, a confining pressure boosting pipe for simulating formation pressure being provided at the top of the middle portion of the core barrel, a sealing rubber sleeve being provided inside the core barrel, a simulated core being provided inside the sealing rubber sleeve, a plurality of fracture creation holes being provided on the side wall of the core barrel, a bracket being provided on one side of the fracture creation hole, and a fracture creation motor being provided on the bracket for docking with the fracture creation hole.

[0008] Furthermore, a support leg is provided on each side of the bottom of the core barrel.

[0009] Description: The support legs are used to keep the core barrel stable during the displacement and fracture creation processes.

[0010] Furthermore, the suturing holes are arranged at equal intervals of 3 to 8.

[0011] Note: By optimizing and adjusting the number of suturing holes, multi-point suturing can be achieved and the spacing can be reasonably controlled.

[0012] Furthermore, a support plate for carrying the seam-making motor is provided in the middle of the bracket, and a plurality of slide grooves are provided on the support plate, and the position of each slide groove corresponds to the position of the seam-making hole. A slider is provided at the rear end of the seam-making motor, and the slider is slidably connected to the slide groove.

[0013] Description: The positioning of the seam-making motor is achieved through the support plate, which facilitates rapid seam-making.

[0014] Furthermore, the output end of the front end of the seam-making motor is provided with a seam-making rod for impacting the outer wall of the simulated rock core, and the rear end of the slider is provided with a limit block. When the limit block and the support plate abut against each other, the front end of the seam-making rod abuts against the simulated rock core.

[0015] Note: The limit block is used to keep the slider and the seam-making motor stable.

[0016] Furthermore, a detachable sealing knob is provided at the suturing hole, and a sealing rubber sheet is provided at the front end of the sealing knob. When the sealing knob is connected to the suturing hole, the sealing rubber sheet is connected to the reserved hole provided on the sealing rubber sleeve.

[0017] Note: The sealing film is used to keep the core tight during the displacement process.

[0018] Furthermore, the sealing knob is threadedly connected to the suturing hole.

[0019] Furthermore, a hook is provided on one side of the bracket, and an air guide tube is placed on the hook.

[0020] Note: After the slits are created, the holes are cleaned by blowing air through the air guide tube to blow out the rock debris in the holes to avoid loose sealing during the subsequent core flooding process.

[0021] The beneficial effects of the utility model are:

[0022] The utility model discloses a displacement device for indoor experiments in gas injection and oil production with synchronous core fracture creation. By modifying the outer wall of the core barrel, it can cooperate with the fracture creation motor placed on the bracket in advance, and immediately simulate fracture creation on the core after the displacement is completed. The fracture creation has high precision and is convenient and quick to operate, which has guiding significance for indoor simulation of oil and gas field development. The utility model discloses a displacement device for indoor experiments in gas injection and oil production with synchronous core fracture creation. By placing the fracture creation motor on a dedicated bracket, it can quickly realize the positioning of the fracture creation hole in conjunction with the slider, thereby improving the fracture creation efficiency, and strictly controlling the distance between the fracture creation rod and the simulated core to avoid excessive impact on the core, thereby failing to obtain the desired micro-cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of a displacement device for indoor experiments of gas injection and oil production with synchronous core fracture creation in the utility model;

[0024] Figure 2 This is a top view of a displacement device for indoor experiments of gas injection and oil production with synchronous core fracture creation according to the utility model;

[0025] Figure 3 The utility model is a cross-sectional view of the middle part of a core barrel of a displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation.

[0026] Among them, 1-core barrel, 11-sealing cover, 12-sealing rubber sleeve, 13-fracture hole, 14-support leg, 15-sealing knob, 16-sealing film, 17-reserved hole, 2-simulated injection pipe, 3-simulated production pipe, 4-confining pressure boosting pipe, 5-simulated core, 6-bracket, 61-support plate, 62-chute, 63-slider, 64-limiting block, 7-fracture motor, 71-fracture rod, 8-air guide tube. DETAILED DESCRIPTION

[0027] Example 1

[0028] A synchronous core fracture-forming gas injection displacement device for indoor experimental oil production includes a horizontally placed core barrel 1, with a support leg 14 provided on each side of the bottom of the core barrel 1, a sealing cover 11 provided at both ends of the core barrel 1, a simulated injection pipe 2 provided on a front sealing cover 11, and a simulated production pipe 3 provided on a rear sealing cover 11, a confining pressure boosting pipe 4 for simulating formation pressure provided at the top of the middle portion of the core barrel 1, a sealing rubber sleeve 12 provided inside the core barrel 1, a simulated core 5 provided inside the sealing rubber sleeve 12, four equally spaced fracture-forming holes 13 provided on the side wall of the core barrel 1, a bracket 6 provided on one side of the fracture-forming hole 13, and a fracture-forming motor 7 provided on the bracket 6 for docking with the fracture-forming hole 13;

[0029] A supporting plate 61 for carrying the slit-making motor 7 is provided in the middle of the bracket 6, and a plurality of slide grooves 62 are provided on the supporting plate 61. The position of each slide groove 62 corresponds to the position of the slit-making hole 13. A slider 63 is provided at the rear end of the slit-making motor 7. The slider 63 is slidably connected to the slide groove 62. The output end of the front end of the slit-making motor 7 is provided with a slit-making rod 71 for impacting the outer wall of the simulated rock core 5. A limit block 64 is provided at the rear end of the slider 63. When the limit block 64 and the supporting plate 61 abut against each other, the front end of the slit-making rod 71 abuts against the simulated rock core 5. A detachable sealing knob 15 is provided at the slit-making hole 13. A sealing rubber sheet 16 is provided at the front end of the sealing knob 15. When the sealing knob 15 is docked with the slit-making hole 13, the sealing rubber sheet 16 is docked with the reserved hole 17 provided on the sealing rubber sleeve 12. The sealing knob 15 is threadedly connected to the slit-making hole 13.

[0030] A hook is provided on one side of the bracket 6, and an air guide tube 8 is placed on the hook.

[0031] Example 2

[0032] This embodiment differs from embodiment 1 in that:

[0033] The side wall of the core barrel 1 is provided with three slit holes 13 arranged at equal intervals.

[0034] Example 3

[0035] This embodiment differs from embodiment 1 in that:

[0036] The side wall of the core barrel 1 is provided with eight slit holes 13 arranged at equal intervals.

[0037] Working principle:

[0038] The working principle of the present utility model is briefly described below.

[0039] Before conducting the core flooding experiment, the simulated core 5 must be placed in a thermostat at 80°C for 12 hours to fully dry it. The simulated core 5 is then placed in the core barrel 1, centered. Sealing caps 11 are added to both sides, tightened, and each sealing knob 15 is tightened to seal each sealing rubber sheet 16 with each reserved hole 17.

[0040] Then, the confining pressure operation is carried out. Water is injected through the confining pressure booster pipe 4 to form a pressure between the sealing rubber sleeve 12 and the core barrel 1 to simulate the formation pressure. Since the sealing rubber sleeve 12 is provided with a reserved hole 17, the sealing performance is affected and it cannot operate under high pressure. Therefore, a lower pressure is used when applying confining pressure. A manual metering pump is used to pressurize the annular space between the core barrel 1 and the sealing rubber sleeve 12, and after venting, the confining pressure reaches about 7MPa. Let it stand for a while and observe the changes in the confining pressure. If the confining pressure remains unchanged or drops slightly, it can eventually be guaranteed to be around 6MPa.

[0041] Then, the configured simulated formation oil is injected through the simulated injection pipe 2 to saturate the interior of the simulated core 5 with the simulated formation oil. Then, the configured simulated formation water is injected through the simulated injection pipe 2 to simulate the process of water flooding oil. The produced fluid is collected through the simulated production pipe 3 to calculate the remaining oil content in the simulated core after water flooding oil, and the recovery factor is calculated;

[0042] Then, the simulated rock core 5 is fractured, the fracture motor 7 is placed at the position where the fracture needs to be made, the sealing knob 15 is removed, and the slider 63 and the rock slide 62 are slid until the limit block 64 and the rear side of the support plate 61 abut against each other. At this time, the front end of the fracture rod 71 passes through the fracture hole 13 and the reserved hole 17 and abuts against the side wall of the simulated rock core 5. Here, we need to strictly control the distance between the fracture rod 17 and the simulated rock core 5 to avoid causing excessive impact on the rock core, thereby failing to obtain the desired micro-cracks. This step can be achieved by calculating the placement distance of the direct 6;

[0043] Turn on the slit motor 7 to drive the slit rod 71 to continuously impact the side wall of the simulated core 5 to create a slit. Then withdraw the slit rod 71 and use the air pipe 8 to connect to the external air source to blow air to clean the rock debris inside the slit hole 13. Then tighten the sealing knob.

[0044] The water flooding process with the same operation steps was then repeated to calculate the recovery rate after fracture creation, thereby obtaining the effect of fracture creation on improving crude oil recovery in the simulated core 5, which has certain guiding significance for tertiary oil recovery in oil and gas field development.

Claims

1. A displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation, characterized in that: The invention comprises a horizontally placed core barrel (1), wherein sealing covers (11) are provided at both ends of the core barrel (1), a simulated injection pipe (2) is provided on the sealing cover (11) at the front end, and a simulated production pipe (3) is provided on the sealing cover (11) at the rear end, a confining pressure boosting pipe (4) for simulating formation pressure is provided at the top of the middle part of the core barrel (1), a sealing rubber sleeve (12) is provided inside the core barrel (1), a simulated core (5) is provided inside the sealing rubber sleeve (12), a plurality of slit holes (13) are provided on the side wall of the core barrel (1), a bracket (6) is provided on one side of the slit hole (13), and a slit motor (7) for docking with the slit hole (13) is provided on the bracket (6).

2. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 1, characterized in that: A support leg (14) is provided on each side of the bottom of the core barrel (1).

3. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 1, characterized in that: The suturing holes (13) are arranged at equal intervals of 3 to 8.

4. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 1, characterized in that: A support plate (61) for carrying the suturing motor (7) is provided in the middle of the bracket (6), and a plurality of slide grooves (62) are provided on the support plate (61), and the position of each slide groove (62) corresponds to the position of the suturing hole (13). A slider (63) is provided at the rear end of the suturing motor (7), and the slider (63) is slidably connected to the slide groove (62).

5. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 4, characterized in that: The output end of the front end of the seam-forming motor (7) is provided with a seam-forming rod (71) for impacting the outer wall of the simulated rock core (5), and the rear end of the slider (63) is provided with a limit block (64). When the limit block (64) and the support plate (61) abut against each other, the front end of the seam-forming rod (71) abuts against the simulated rock core (5).

6. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 1, characterized in that: A detachable sealing knob (15) is provided at the suturing hole (13), and a sealing rubber sheet (16) is provided at the front end of the sealing knob (15). When the sealing knob (15) is connected to the suturing hole (13), the sealing rubber sheet (16) is connected to the reserved hole (17) provided on the sealing rubber sleeve (12).

7. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 6, characterized in that: The sealing knob (15) is threadedly connected to the suturing hole (13).

8. The displacement device for indoor experimental gas injection and oil production with synchronous core fracture creation according to claim 1, characterized in that: A hook is provided on one side of the bracket (6), and an air guide tube (8) is placed on the hook.

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