A high-temperature and high-pressure imbibition device

Abstract

The present invention discloses a high-temperature and high-pressure imbibition device, which relates to the technical field of imbibition experiments in petroleum engineering. The device includes an imbibition holder cylinder, a metering tube, a collection funnel, and an injection pump. The interior of the imbibition holder cylinder is used to accommodate the core. The smaller end of the collection funnel is connected to the bottom end of the metering tube, and the larger end of the collection funnel is located directly above the core. The injection pump is used to inject displacement fluid into the imbibition holder cylinder. In the high-temperature and high-pressure imbibition device of the present invention, the core is placed under a simulated formation environment for imbibition displacement, and the small oil droplets on the surface of the core are sprayed and swept, so that the displaced small oil droplets are separated into the glass metering tube in a timely manner for measurement. During the high-temperature heating process of the displacement fluid, the pressure value during the heating process of the displacement fluid is controlled by a constant-speed and constant-pressure pump to ensure that the displacement fluid always maintains a constant pressure state during the heating process.

Description

Technical Field

[0001] The present invention relates to the technical field of imbibition experiments in petroleum engineering, and particularly to a high-temperature and high-pressure imbibition device. Background Art

[0002] The main characteristic of tight oil is low permeability, and the stored fluid can hardly flow. At present, the main method for developing tight oil reservoirs is depletion exploitation, and problems such as rapid decline of formation energy and rapid production decline are shown during the development. Regarding imbibition, some research has been carried out by domestic and foreign scholars, but it is limited to the imbibition research of crude oil and water in medium-high permeability storage matrices. There is less experimental research on the imbibition of matrix and fracturing fluid in ultra-low permeability and tight storage. Therefore, conducting imbibition experiments in ultra-low permeability and tight storage rooms has certain guiding significance for improving the recovery rate and development effect of such storage. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides a high-temperature and high-pressure imbibition device, which places a core under a simulated formation environment condition for imbibition replacement.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a high-temperature and high-pressure imbibition device, including an imbibition holder cylinder, a metering tube, a collection funnel, and an injection pump; the interior of the imbibition holder cylinder is used to accommodate a core, the smaller end of the collection funnel is connected to the bottom end of the metering tube, and the larger end of the collection funnel is located directly above the core; the injection pump is used to inject a replacement liquid into the imbibition holder cylinder.

[0006] Optionally, a lower plug of the holder is provided at the bottom of the imbibition holder cylinder, and the lower plug of the holder is detachably and sealingly connected to the imbibition holder cylinder; the lower plug of the holder is used to carry the core.

[0007] Optionally, an upper plug of the holder is provided at the top of the imbibition holder cylinder, the outer wall of the upper plug of the holder is detachably and sealingly connected to the imbibition holder cylinder, the top of the metering tube is arranged at the bottom of the upper plug of the holder, and the metering tube is connected to a metering tube drain valve through a pipeline that penetrates through the upper plug of the holder.

[0008] Optionally, a high-pressure viewing window is provided on the imbibition holder cylinder at the same height as the metering tube.

[0009] Optionally, a replacement liquid drain valve is provided on the upper part of the imbibition holder cylinder.

[0010] Optionally, a pressure sensor is provided on the upper part of the imbibition holder cylinder.

[0011] Optionally, a temperature sensor is provided on the imbibition gripper cylinder body.

[0012] Optionally, a pneumatic injection mechanism is provided at the lower part of the imbibition gripper cylinder body. The pneumatic injection mechanism includes a pneumatic piston cylinder and an injection pipe. The pneumatic piston cylinder is communicated with the inlet end of the injection pipe, and the outlet end of the injection pipe is arranged around the top of the core.

[0013] Optionally, the pneumatic injection mechanism further includes a pneumatic valve. One pneumatic valve is arranged at each end of the cylinder body of the pneumatic piston cylinder. One ends of the two pneumatic valves are communicated with one end of a water suction pipe, the other end of the water suction pipe is communicated with the inside of the imbibition gripper cylinder body, and the other ends of the two pneumatic valves are connected with the inlet end of the injection pipe.

[0014] The present invention has achieved the following technical effects compared with the prior art:

[0015] In the high-temperature and high-pressure imbibition device of the present invention, the core is placed in a simulated formation environment for imbibition replacement, and the small oil droplets on the surface of the core are sprayed and swept, so that the replaced small oil droplets are timely separated into the glass metering tube for metering.

[0016] During the high-temperature heating process of the displacement liquid, the pressure value of the displacement liquid during the heating process is controlled by a constant-speed and constant-pressure pump to ensure that the displacement liquid always maintains a constant pressure state during the heating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic structural diagram of the high-temperature and high-pressure imbibition device of the present invention;

[0019] Figure 2 It is a schematic structural diagram of the pneumatic injection mechanism in the high-temperature and high-pressure imbibition device of the present invention;

[0020] Figure 3 It is a schematic structural diagram of the pneumatic injection mechanism in the high-temperature and high-pressure imbibition device of the present invention after being reversed.

[0021] Description of reference numerals: 1, metering pipe drain valve; 2, displacement liquid drain valve; 3, pressure sensor; 4, high-pressure viewing window; 5, imbibition holder cylinder; 6, temperature sensor; 7, pneumatic piston cylinder; 8, lower plug of the holder; 9, core; 10, injection pipe; 11, collection funnel; 12, metering glass tube; 13, upper plug of the holder; 14, pneumatic valve of the injection pump; 15, injection pump; 16, water suction pipe; 17, pneumatic valve. Detailed implementation manners

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] As Figures 1 to 3 shown, this embodiment provides a high-temperature and high-pressure imbibition device, including an imbibition holder cylinder, a metering pipe, a collection funnel, and an injection pump; the interior of the imbibition holder cylinder is used to accommodate a core, the smaller end of the collection funnel is connected to the bottom end of the metering pipe, and the larger end of the collection funnel is located directly above the core; the injection pump is used to inject displacement liquid into the imbibition holder cylinder.

[0024] In this specific embodiment, as Figure 1 shown, the metering pipe is made of a glass tube. A suitable metering glass tube 12 is selected, connected to the upper plug 13 of the holder, and installed on the imbibition holder cylinder 5, and the collection funnel 11 is installed. The core 9 is fixed on the lower plug 8 of the holder, and then the lower plug 8 of the holder is hermetically sealed with the imbibition holder cylinder 5, and preparations are started to inject displacement liquid into the imbibition holder cylinder 5.

[0025] The constant-speed and constant-pressure pump 15 can be used both as a pressurizing pump to simulate the formation pressure of the core and as a constant-pressure device for the internal pressure of the holder. If the internal pressure of the holder increases, the constant-speed and constant-pressure pump 15 will automatically withdraw the pump to the set pressure value. If the internal pressure of the holder decreases, the constant-speed and constant-pressure pump 15 will automatically feed the pump to the set pressure value. The constant-speed and constant-pressure pump 15 is used to pre-fill the displacement liquid into the imbibition holder cylinder 5, and the metering pipe drain valve 1 and the displacement liquid drain valve 2 are opened until liquid flows out of the above two drain valves, and then the injection is stopped. Then, oil is injected into the metering glass tube 12 from the metering pipe drain valve 1 to form an initial interface for volume measurement (the initial interface must exceed the scale line at the uppermost end of the metering glass tube). After closing the metering pipe drain valve 1 and the displacement liquid drain valve 2, the volume measurement can be carried out by means of, but not limited to, visual image measurement through the high-pressure viewing window 4 with the help of a camera system.

[0026] Heat the displacement fluid to the set temperature, use a constant speed and constant pressure pump 15 to pressurize the imbibition gripper cylinder 5 to the set pressure and set the constant pressure mode until the temperature is stable. The system can detect the pressure and temperature inside the imbibition gripper cylinder 5 through the pressure sensor 3 and the temperature sensor 6 at any time.

[0027] During the test, the oil droplets imbibed will slowly gather and grow until they break away from the surface of the core 9. The oil droplets rise and are collected into the measuring glass tube 12 through the collection funnel 11. Due to the different specific gravities of oil and water, the oil droplets will undergo gravity separation in the measuring glass tube 12. The oil droplets float upward and finally mix with the oil at the initial measuring interface, forming a change in the oil liquid level, and the volume of the oil droplets is calculated through the camera measurement system.

[0028] When some small oil droplets cannot freely leave the core 9, it is necessary to open the pneumatic injection mechanism to inject the small oil droplets on the surface of the core if necessary. As Figure 2 and 3 , connect the pneumatic piston cylinder 7. One end of the pneumatic piston cylinder 7 is connected to the displacement fluid inside the imbibition gripper cylinder 5, and the other end of the pneumatic piston cylinder 7 is connected to the injection pipe 10 inside the imbibition gripper cylinder 5. When the pneumatic piston cylinder 7 reciprocates, it sucks in the displacement fluid in the imbibition gripper cylinder 5 while spraying the displacement fluid onto the surface of the core 9 through the injection pipe 10 to wash the small oil droplets on the surface of the core 9. In order to prevent the injection pipe of the pneumatic piston cylinder 7 from sucking in small oil droplets, the pneumatic valve 17 can be used to set the water suction pipe 16 to be in the water suction state all the time, and the injection pipe to be in the spraying state all the time (as Figure 2 and 3 shown). The reciprocating motion of the pneumatic piston cylinder 7 ensures that the total amount of the displacement fluid in the gripper remains unchanged, so it will not affect the pressure condition in the gripper.

[0029] This measurement method requires calibrating the volume of the measuring glass tube 12 in advance. The calibration method is to draw two scale lines on the upper and lower parts of the glass tube, measure the total volume between the two scale lines using a high-precision balance, then use the camera to find these two scale lines in the image and perform image pixel allocation, and measure the imbibition amount of the core through the pixel positions corresponding to the boundary surface.

[0030] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claimed rights.

[0031] In this specification, specific examples are used to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only for helping to understand the method of the present invention and its core idea. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A high-temperature and high-pressure imbibition device, characterized in that, It includes an imbibition gripper cylinder body, a metering tube, a collection funnel and an injection pump; the interior of the imbibition gripper cylinder body is used to accommodate the core, the smaller end of the collection funnel is connected to the bottom end of the metering tube, and the larger end of the collection funnel is located directly above the core; the injection pump is used to inject displacement fluid into the imbibition gripper cylinder body. A pneumatic injection mechanism is provided at the lower part of the imbibition gripper cylinder body, and the pneumatic injection mechanism includes a pneumatic piston cylinder and an injection tube; the pneumatic piston cylinder is communicated with the inlet end of the injection tube, and the outlet end of the injection tube is arranged around the top of the core. The pneumatic injection mechanism further includes a pneumatic valve. One pneumatic valve is arranged at each end of the cylinder body of the pneumatic piston cylinder. One end of the two pneumatic valves is communicated with one end of a water suction pipe, the other end of the water suction pipe is communicated with the interior of the imbibition gripper cylinder body, and the other end of the two pneumatic valves is connected to the inlet end of the injection tube.

2. The high-temperature and high-pressure imbibition device according to claim 1, characterized in that, A lower plug of the gripper is provided at the bottom of the imbibition gripper cylinder body, and the lower plug of the gripper is detachably and sealingly connected to the imbibition gripper cylinder body; the lower plug of the gripper is used to carry the core.

3. The high-temperature and high-pressure imbibition device according to claim 1, characterized in that, An upper plug of the gripper is provided at the top of the imbibition gripper cylinder body. The outer wall of the upper plug of the gripper is detachably and sealingly connected to the imbibition gripper cylinder body. The top of the metering tube is arranged at the bottom of the upper plug of the gripper, and the metering tube is connected to a metering tube drain valve after passing through the upper plug of the gripper through a pipeline.

4. The high-temperature and high-pressure imbibition device according to claim 1, characterized in that, A high-pressure viewing window is provided on the imbibition gripper cylinder body at the same height as the metering tube.

5. The high-temperature and high-pressure imbibition device according to claim 1, characterized in that, A displacement fluid drain valve is provided at the upper part of the imbibition gripper cylinder body.

6. The high-temperature and high-pressure imbibition device according to claim 1, characterized in that, A pressure sensor is provided at the upper part of the imbibition gripper cylinder body.

7. The high-temperature and high-pressure imbibition device according to claim 1, characterized in that, A temperature sensor is provided on the imbibition gripper cylinder body.

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