Device for measuring three-dimensional core oil-water relative permeability curve

Abstract

The utility model provides a device for measuring a three-dimensional core oil-water relative permeability curve. The device comprises an oil-water conveying mechanism, a core holder, a back-pressure valve and an oil-water separation tank which are connected in sequence, the oil-water conveying mechanism comprises piston containers, pistons, piston rods, a rotating shaft, rotating discs and a power mechanism, during use, the power mechanism drives the two rotating discs to rotate at the same rotating speed, the two piston containers store oil and water respectively, and the rotating discs drive the piston rods to move through hinge rods; the movable rod is used for determining the hinged position of the hinge rod and the rotating discs and the distance between the center shafts of the rotating discs, and the movable rod can move in the radial direction of the rotating discs, so that the axial displacement amount of the piston rod when the movable rod rotates by one circle is changed, and then the flow of liquid discharged when the movable rod rotates by one circle can be controlled. The flow of the two piston containers is in direct proportion to the distance between the two moving rods and the center shaft of the rotating disc, the flow ratio of the two piston containers can be changed by moving the moving rods along the radial grooves, and control is quite accurate.

Description

Technical Field

[0001] The utility model belongs to the technical field of indoor simulation of oil reservoirs, and in particular relates to a device for measuring a three-dimensional core oil-water relative permeability curve. Background Art

[0002] The oil-water relative permeability curve, also known as the oil-water relative permeability curve, comprehensively reflects the characteristics of oil-water two-phase flow and is an essential foundational data point for reservoir numerical simulation. This curve significantly influences oil production and water content in reservoir numerical simulations, and therefore, is typically obtained through laboratory experiments. During these experiments, cores are displaced using varying ratios of oil and water to simulate the fluid flow conditions found in actual reservoirs.

[0003] At present, there are many devices for measuring oil-water phase permeability curves, but these devices generally have the problem of insufficient accuracy in terms of oil-water ratio. For example, Chinese patent CN201820446438.6 discloses a device for measuring the oil-water phase permeability curve of three-dimensional core flow. The device connects oil and water to the inlet of the pump at the same time, and drives the oil and water through the same pump. If the oil-water ratio needs to be adjusted, for example, to configure a 9:1 oil-water mixture, it is necessary to manually control the valves on the oil and water pipelines, and cooperate with relevant flow meters or liquid level drop rates to determine the flow rate of oil and water. This operation method is not only cumbersome, but also has large errors, making it difficult to achieve an accurate oil-water ratio. In addition, Chinese patent CN201911285301.2 also discloses an oil-water phase permeability test device. The device uses two piston containers to displace two fluids, connects the driving ends of the two piston containers to the outlet of the same injection pump, and aims to displace the movement of the two pistons through the same injection pump. However, it is difficult for this device to accurately control the distribution amount of the fluid output by the injection pump at the driving ends of the two piston containers, and it is difficult to achieve precise oil-water ratio control.

[0004] In summary, the existing oil-water phase permeability curve measurement device has the problem of insufficient accuracy in terms of oil-water ratio. There is an urgent need for a device that can accurately control the oil-water ratio to improve the accuracy and reliability of oil-water phase permeability curve measurement. Utility Model Content

[0005] In view of this, the purpose of the present invention is to provide a device for measuring the three-dimensional core oil-water permeability curve. This device improves the piston container and power structure in CN201911285301.2, which can accurately control the flow rate of the two piston containers to achieve the purpose of accurately controlling the oil-water ratio.

[0006] In order to achieve the above objectives, the present utility model adopts the following technical solutions.

[0007] A device for measuring a three-dimensional oil-water relative permeability curve of a core, comprising an oil-water conveying mechanism, a core holder, a back pressure valve, and an oil-water separation tank connected in sequence, and an oil-water ratio detector for detecting the oil-water ratio in the fluid at the core holder outlet, wherein the core holder is used to hold the core, and the oil-water conveying mechanism is used to convey an oil-water mixture to the core holder, and the oil-water conveying mechanism comprises:

[0008] Two piston containers, each with an outlet pipeline and an inlet pipeline at the non-driving end, and a one-way valve on both pipelines to ensure one-way flow of fluid from the inlet pipeline and the non-driving end to the outlet pipeline; each piston container is equipped with a piston and a piston rod, wherein the piston is sealed with the inner wall of the piston container, one end of the piston rod is fixedly connected to the piston, and the other end is arranged along the axial direction of the piston container and passes through the driving end of the piston container and is in clearance fit with it;

[0009] A rotating shaft, which is arranged horizontally and has its middle portion supported on one end of the support rod;

[0010] Two turntables, each carried at both ends of the rotating shaft, parallel to each other and rotatable, each turntable having radial grooves arranged along its radial direction, and scales provided next to the radial grooves for indicating the distance between each radial groove and the centerline of the turntable;

[0011] A power mechanism, used for driving the two turntables to rotate at the same speed;

[0012] Among them, each turntable corresponds to a moving rod, a hinged rod and a piston rod, which is used to drive the piston rod to move axially along the piston container; the moving rod is arranged axially along the turntable and is fixed in the corresponding radial groove in a detachable manner, and one end of the hinged rod is hinged to the corresponding moving rod, and the other end is hinged to the corresponding piston rod.

[0013] As a specific embodiment of the present invention, two turntables are fixedly connected to the rotating shaft, the rotating shaft is rotatably connected to the support rod, and teeth are arranged on the turntable in a circumferential direction. The power mechanism includes a rotating device and a gear coaxially fixedly connected to the output end of the rotating device. The gear is engaged with the teeth of the turntable, so that the turntable can be driven to rotate by the rotating device.

[0014] As a specific implementation of the present invention, the rotating device is a motor.

[0015] As a specific embodiment of the present invention, two turntables are rotatably connected to the rotating shaft, and teeth are arranged on the opposite surfaces of the two turntables in the circumferential direction. The power mechanism includes a rotating device and a gear coaxially fixedly connected to the output end of the rotating device. The gear is located between the two turntables and simultaneously engages with the teeth of the two turntables, thereby driving the two turntables to rotate in opposite directions.

[0016] As a specific embodiment of the present invention, it further includes a water tank and an oil tank, wherein the water tank is connected to the inlet pipeline of one piston container, and the oil tank is connected to the inlet pipeline of the other piston container.

[0017] As a specific embodiment of the present invention, the oil-water separation tank is provided with an oil phase outlet pipeline and a water phase outlet pipeline, the oil phase outlet pipeline is connected to the oil tank, and the water phase outlet pipeline is connected to the water tank.

[0018] The beneficial effects of the utility model are as follows:

[0019] In the present invention, the turntable drives the piston rod to move back and forth along the axial direction of the piston container through the hinged rod. One rotation of the turntable will drive the piston to complete a reciprocating motion along the piston container. The distance of each reciprocating motion is determined by the rotation diameter of the hinge point between the hinged rod and the turntable (equal to twice the diameter). In the present invention, the moving rod can move along the radial direction of the turntable, thereby changing the rotation diameter of the hinge point between the hinged rod and the turntable, that is, changing the displacement of the piston rod when rotating one circle, and then controlling the flow rate of the liquid discharged when rotating one circle. Since the rotation speed of the two turntables is the same, the flow rate of the two piston containers is proportional to the distance between the two moving rods and the central axis of the turntable. The flow ratio between the two can be changed by moving the moving rod along the radial groove, and the control is very accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 2 yes Figure 1 Schematic diagram of the connection between the piston container and the turntable;

[0022] Figure 3 yes Figure 1 Schematic diagram of the connection between the turntable and the piston rod;

[0023] Figure 4 is a schematic structural diagram of a turntable in another embodiment;

[0024] In the figure, core holder 100; oil-water ratio detector 200; back pressure valve 300; oil-water separation tank 400; water tank 500; oil tank 600; oil phase outlet pipeline 700; water phase outlet pipeline 800;

[0025] Annular pressure pump 110; differential pressure gauge 120; piston container 510; piston 520; piston rod 530; rotating shaft 540; rotating disk 550; power mechanism 560; moving rod 570; hinged rod 580; support rod 590;

[0026] Inlet pipeline 511; outlet pipeline 512; radial groove; tooth portion; rotating device 561; gear 562. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with the embodiments and drawings.

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for which protection is claimed, but merely represents selected embodiments of the present invention.

[0029] Example

[0030] Please refer to Figures 1 to 3 , which shows a specific structure of the device for measuring the three-dimensional oil-water relative permeability curve of a core according to the present invention. The device comprises an oil-water conveying mechanism, a core holder 100, an oil-water ratio detector 200, a back-pressure valve 300, and an oil-water separation tank 400, which are connected in sequence. The core holder 100 contains a core (not shown) and is equipped with an annular pressure pump 110 and a differential pressure gauge 120. The annular pressure pump 110 controls the annular pressure applied by the core holder 100 to the core. The differential pressure gauge 120 is connected to the inlet and outlet of the core holder 100, respectively, to measure the fluid pressure differential across the core. The oil-water conveying mechanism delivers a specific oil-water mixture to the core holder 100, displacing the core with the mixture. The oil-water ratio detector 200 detects the oil-water ratio in the fluid at the outlet of the core holder 100. The back-pressure valve 300 controls the outlet pressure of the core holder 100. The oil-water separation tank 400 is used to receive and separate the outlet fluid of the core holder 100 .

[0031] Please refer to Figure 2The oil-water transfer mechanism includes a piston container 510, a piston 520, a piston rod 530, a rotating shaft 540, a rotating disk 550, and a power mechanism 560. There are two piston containers 510, one for transferring oil and one for transferring water. Each piston container 510 has an inlet pipeline 511 and an outlet pipeline 512 at its non-driving end. Both the inlet pipeline 511 and the outlet pipeline 512 are equipped with one-way valves to prevent the fluid in the piston container 510 from flowing into the inlet pipeline 511 and to prevent the fluid in the outlet pipeline 512 from flowing into the piston container 510, thereby ensuring a one-way flow of fluid from the inlet pipeline 511 and the non-driving end to the outlet pipeline 512. The piston 520 is located in the piston container 510 and is sealed to the piston container 510. Each piston container 510 is equipped with a piston rod 530 arranged axially along the piston container 510. One end of the piston rod 530 is fixedly connected to the piston 520, while the other end passes through the driving end of the piston container 510 and is in a clearance fit with it. The middle part of the rotating shaft 540 is supported by one end of the support rod 590, and the rotating shaft 540 is arranged horizontally. There are two turntables 550, and the two turntables 550 are supported at both ends of the rotating shaft 540 respectively. At the same time, the two turntables 550 are parallel to each other and can rotate. Each turntable 550 is provided with a radial groove arranged along its radial direction, and a scale (not shown in the figure) is provided next to the radial groove to indicate the distance between each radial groove and the center line of the turntable 550, so that the radius of the moving rod 570 when rotating can be determined. The power mechanism 560 is used to drive the two turntables 550 to rotate at the same speed. Each turntable 550 corresponds to a piston rod 530, a moving rod 570 and a hinged rod 580. Among them, the moving rods 570 are arranged along the axial direction of the turntable 550 and are fixed in the corresponding radial groove in a detachable manner. One end of the hinged rod 580 is hinged to the corresponding moving rod 570, and the other end is hinged to the corresponding piston rod 530. When the turntable 550 rotates, it drives the piston 520 to move back and forth along the axial direction of the piston container 510.

[0032] In the present invention, the turntable drives the piston rod to move back and forth along the axial direction of the piston container through the hinged rod. One rotation of the turntable will drive the piston to complete a reciprocating motion along the piston container. The distance of each reciprocating motion is determined by the rotation diameter of the hinge point of the hinged rod and the turntable (equal to twice the diameter), that is, it is determined by the distance between the moving rod and the center line of the turntable. In the present invention, the moving rod can move along the radial direction of the turntable, thereby changing the distance between the moving rod and the center line of the turntable, that is, changing the displacement of the piston rod when rotating one circle, and then controlling the flow rate of the liquid discharged when rotating one circle. Since the rotation speeds of the two turntables are the same, the flow rate of the two piston containers is proportional to the distance between the two moving rods and the center axis of the turntable. The flow ratio between the two can be changed by moving the moving rod along the radial groove, and the control is very accurate.

[0033] The movable rod 570 of the present invention can move radially along the turntable 550, thereby varying the axial displacement of the piston rod 530 during one rotation, thereby controlling the flow rate of liquid discharged during one rotation. Since the two turntables 550 rotate at the same speed, the flow rates of the two piston containers 510 are proportional to the distance between the movable rods 570 and the central axis of the turntable 550. By moving the movable rod 570 along the radial groove, the flow rate ratio between the two can be varied, providing highly accurate control.

[0034] In some embodiments, as Figure 3 As shown, the middle portion of the rotating shaft 540 is rotatably connected to the support rod 590, and the two rotating disks 550 are fixedly connected to the ends of the rotating shaft 540, so that the two rotating disks 550 and the rotating shaft 540 rotate synchronously. To facilitate driving the rotating disks, teeth are arranged along the circumference of the rotating disks 550. The power mechanism 560 includes a rotating device 561 and a gear 562. The gear 562 is coaxially fixedly connected to the output end of the rotating device 561. The gear 562 meshes with the teeth of the rotating disk 550, thereby driving the rotating disk 550 to rotate through the rotating device 561.

[0035] In some embodiments, as Figure 4 As shown, two turntables 550 are rotatably connected to a rotating shaft 540, and the middle portion of the rotating shaft 540 is fixedly connected to a support rod 590. Gears are arranged circumferentially on opposing surfaces of the two turntables 550. A power mechanism 560 includes a rotating device 561 and a gear 562 (bevel gear). Gear 562 is coaxially fixedly connected to the output end of the rotating device 561. Gear 562 is located between the two turntables 550 and simultaneously meshes with the teeth of the two turntables 550, thereby driving the two turntables 550 to rotate in opposite directions.

[0036] In some embodiments, the oil-water separator tank 400 further includes a water tank 500 and an oil tank 600, wherein the water tank 500 is connected to the inlet pipeline 511 of one piston container 510, and the oil tank 600 is connected to the inlet pipeline 511 of the other piston container 510. In other embodiments, the oil-water separator tank 400 is provided with an oil phase outlet pipeline 700 and a water phase outlet pipeline 800, wherein the oil phase outlet pipeline 700 is connected to the oil tank 600, and the water phase outlet pipeline 800 is connected to the water tank 500, thereby achieving oil-water circulation.

[0037] The rotating device 561 in the present invention can be a motor or other device.

[0038] In some embodiments, one end of the moving rod 570 is provided with a threaded section. When in use, one end of the moving rod 570 passes through the radial groove, and then the moving rod 570 is fixed to the turntable 550 by nuts on both sides of the turntable 550. When the moving rod needs to be moved, just loosen the nut, which is simple to operate.

[0039] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the embodiments of the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A device for measuring the three-dimensional oil-water relative permeability curve of a core, comprising an oil-water conveying mechanism, a core holder, a back pressure valve, an oil-water separation tank, and an oil-water ratio detector connected in sequence, characterized in that: The oil-water transportation mechanism includes: Two piston containers, each with an outlet pipeline and an inlet pipeline at the non-driving end, and a one-way valve on both pipelines to ensure one-way flow of fluid from the inlet pipeline and the non-driving end to the outlet pipeline; each piston container is equipped with a piston and a piston rod, wherein the piston is sealed with the inner wall of the piston container, one end of the piston rod is fixedly connected to the piston, and the other end is arranged along the axial direction of the piston container and passes through the driving end of the piston container and is in clearance fit with it; A rotating shaft, which is arranged horizontally and has its middle portion supported on one end of the support rod; Two turntables, each carried at both ends of the rotating shaft, parallel to each other and rotatable, each turntable having radial grooves arranged along its radial direction, and scales provided next to the radial grooves for indicating the distance between each radial groove and the centerline of the turntable; A power mechanism, used for driving the two turntables to rotate at the same speed; Among them, each turntable corresponds to a moving rod, a hinged rod and a piston rod, which is used to drive the piston rod to move axially along the piston container; the moving rod is arranged axially along the turntable and is fixed in the corresponding radial groove in a detachable manner, and one end of the hinged rod is hinged to the corresponding moving rod, and the other end is hinged to the corresponding piston rod.

2. The device for measuring the three-dimensional oil-water relative permeability curve of a core according to claim 1, characterized in that: The two turntables are fixedly connected to the rotating shaft, which is rotatably connected to the support rod. Teeth are arranged on the turntable in a circumferential direction. The power mechanism includes a rotating device and a gear coaxially fixedly connected to the output end of the rotating device. The gear engages with the teeth of the turntable, thereby driving the turntable to rotate through the rotating device.

3. The device for measuring the three-dimensional oil-water relative permeability curve of a core according to claim 1, characterized in that: The two turntables are rotatably connected to the rotating shaft, and teeth are arranged on the opposite surfaces of the two turntables in the circumferential direction. The power mechanism includes a rotating device and a gear coaxially fixedly connected to the output end of the rotating device. The gear is located between the two turntables and engages with the teeth of the two turntables at the same time, thereby driving the two turntables to rotate in opposite directions.

4. A device for measuring a three-dimensional core oil-water relative permeability curve according to claim 2 or 3, characterized in that: The rotating device is a motor.

5. The device for measuring the three-dimensional oil-water relative permeability curve of a core according to claim 1, characterized in that: It also includes a water tank and an oil tank, wherein the water tank is communicated with the inlet pipeline of one piston container, and the oil tank is communicated with the inlet pipeline of the other piston container.

6. The device for measuring the three-dimensional oil-water relative permeability curve of a core according to claim 5, characterized in that: The oil-water separation tank is provided with an oil phase outlet pipeline and a water phase outlet pipeline. The oil phase outlet pipeline is connected to the oil tank, and the water phase outlet pipeline is connected to the water tank.

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