A pressure drive huff and puff device with a measurable imbibition amount and a method of using the same

Abstract

The application discloses a pressure drive and swallowing device capable of measuring imbibition amount, which comprises a core imbibition device and an imbibition amount measuring device. The core imbibition device is clamped by a core clamping assembly to measure the core. In the process of simulating and measuring the oil production of pressure drive and swallowing, the initial volume value of liquid displacement agent, the oil production of the core under the forward displacement of the liquid displacement agent and the oil production of the core under the reverse displacement of the crude oil can be measured in sequence, so that the imbibition amount of each stage in the whole pressure drive and swallowing process can be accurately measured. The measurement data can be used to calculate the oil recovery rate, the problem that accurate experimental data cannot be obtained in scientific research and production can be solved, and the technical blank of the imbibition amount measuring equipment in the dynamic imbibition process is filled. The application further provides a use method of the pressure drive and swallowing device capable of measuring imbibition amount.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration and development, and involves the study of the characteristics and mechanism of oil displacement by seepage in tight sandstone reservoirs. In particular, it relates to a pressure-driven huff and puff device that can measure the amount of seepage and its usage method. Background Technology

[0002] With the depletion of conventional oil and gas resources, tight oil resources have become a hotspot for unconventional oil and gas exploration and development globally, and breakthroughs have been made in tight oil development in North America. my country has abundant and widely distributed tight oil resources, most of which are characterized by low initial production, rapid production decline, and low recovery rates.

[0003] In recent years, scholars both domestically and internationally have conducted extensive research on the characteristics and mechanisms of adsorption-induced oil displacement in tight sandstone reservoirs, achieving a series of results. However, due to limitations in experimental equipment and technology, most studies have focused on static spontaneous adsorption, with relatively little research on dynamic adsorption during water injection displacement huff and puff. In actual water injection development, since oil and water are constantly flowing, the adsorption characteristics and oil-water flow characteristics under dynamic conditions will inevitably differ from those under static conditions. If the conclusions obtained from static adsorption experiments are applied to dynamic adsorption development, it will affect the formulation of subsequent development plans and may even cause irreparable losses to the development. However, currently there is no device that can measure the dynamic adsorption during water injection displacement huff and puff. Therefore, it is necessary to propose a dedicated or similar device to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a pressure-driven huff and puff device and its usage method that can measure the amount of percolation, so as to solve the problem that the dynamic percolation cannot be measured during the water injection displacement huff and puff process in the above-mentioned dynamic percolation research.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a pressure-driven swallowing and puffing device capable of measuring the amount of percolation, comprising:

[0007] A core percolation device includes a core clamping assembly for holding a core to be tested; a first flow channel and a second flow channel are connected to the core clamping assembly; the outer surface of one of the first flow channel and the second flow channel is provided with flow channel scale lines for displaying fluid volume, and is externally connected to a percolation fluid source to introduce percolation fluid into the core to be tested;

[0008] An absorption measurement device includes a buffer bottle and a graduated measuring bottle. The buffer bottle contains a buffer piston that divides the interior of the buffer bottle into a first buffer space and a second buffer space. The measuring bottle contains a measuring piston that divides the interior of the measuring bottle into a first measuring space and a second measuring space. One of the first buffer space and the second buffer space is connected to both the first measuring space and the second measuring space, as well as the other of the first flow channel and the second flow channel. Both the other of the first buffer space and the second buffer space, and the other of the first measuring space and the second measuring space, are connected to a piston reverse-drive device. The measuring bottle is used to measure the volume of fluid within the buffer bottle.

[0009] Optionally, the core percolation device includes a transparent bottle connected to the core clamping assembly; a first flow channel is opened inside the transparent bottle, one end of the first flow channel is connected to the percolation fluid source through a first pipeline, and the other end is connected to one axial end of the core to be tested; a first pump and a first control valve are connected to the first pipeline.

[0010] Optionally, the first flow channel includes a straight flow channel and a funnel-shaped flow channel arranged coaxially therewith. One end of the straight flow channel is connected to the first pipeline, and the other end is connected to the small end of the funnel-shaped flow channel. The large end of the funnel-shaped flow channel is connected to the end of the core sample to be tested.

[0011] Optionally, a limiting cover is provided on the outside of the transparent bottle; the flow channel scale lines are provided on the outer surface of the cylindrical glass bottle, and the limiting cover has a hollow hole for displaying the flow channel scale lines and the rock core to be tested.

[0012] Optionally, the core clamping assembly includes:

[0013] An extrusion cylinder has an axial extrusion chamber inside, and the rock core to be tested is placed at one end of the axial extrusion chamber; the extrusion cylinder is configured such that one end of the rock core to be tested is connected to the transparent bottle;

[0014] An annular cover is fitted over the outside of the extrusion cylinder, forming a closed annular cavity between the annular cover and the outer wall of the extrusion cylinder. A second pipe is provided on the side wall of the annular cover, which communicates with the closed annular cavity, to introduce confining pressure simulated fluid into the closed annular cavity, so that the extrusion cylinder tightly holds the rock core to be tested.

[0015] The base is sealed at one end of the axial extrusion chamber and abuts against the other end of the core sample to be tested. The second flow channel is opened in the base, and one end of the second flow channel is connected to the end of the core sample to be tested, and the other end is connected to one of the first buffer space and the second buffer space through a third pipeline.

[0016] Optionally, the extrusion cylinder is a rubber cylinder.

[0017] Optionally, the annular cover is a metal cover.

[0018] Optionally, the buffer bottle is located between the metering bottle and the percolation metering device; the first buffer space and the first metering space are connected in parallel to the end of the third pipeline away from the second flow channel; the second buffer space and the second metering space are connected in parallel to the piston reverse drive device; a second control valve is provided between the third pipeline and the first buffer space; a third control valve is provided between the first buffer space and the first metering space; a fourth control valve is connected between the second buffer space and the piston reverse drive device; and a fifth control valve is connected between the second metering space and the piston reverse drive device.

[0019] Optionally, it also includes a first fluid discharge pipe and a second fluid discharge pipe, wherein the first fluid discharge pipe is connected in parallel between the second buffer space and the piston reverse drive device, and a sixth control valve is provided on the first fluid discharge pipe; the second fluid discharge pipe is connected in parallel between the second metering space and the piston reverse drive device, and a seventh control valve is provided on the second fluid discharge pipe.

[0020] Optionally, the percolation measurement device further includes a measuring bottle cover and a measuring bottle base, wherein the measuring bottle cover is fitted over the measuring bottle and the bottom of the measuring bottle cover is fixedly connected to the measuring bottle base.

[0021] Optionally, a first metering fluid pipeline is provided through the top of the metering bottle and the top of the metering bottle cover, and the first metering fluid pipeline is connected to the third pipeline; a second metering fluid pipeline is provided through the bottom of the metering bottle, the bottom of the metering bottle cover, and the base of the metering bottle, and the piston reverse drive device and the second fluid discharge pipe are connected in parallel to the second metering fluid pipeline.

[0022] Optionally, the piston reverse drive device is an air pump or a water pump.

[0023] Optionally, the permeation fluid source includes a surfactant or displacing agent with a certain pore volume, wherein the displacing agent is a liquid or a gas.

[0024] Meanwhile, this invention proposes a method of using the pressure-driven huff and puff device based on the above-mentioned measurable percolation volume, comprising:

[0025] The percolating fluid is introduced into one of the first and second channels, which has the channel scale lines, and the initial amount of percolating fluid is measured through the channel scale lines.

[0026] The permeation fluid permeates into the core sample and displaces the crude oil within it. All the crude oil displaced from the core sample enters the buffer bottle for reception. Then, the buffer piston is reversed by the piston reverse-drive device to displace all the crude oil in the buffer bottle into the metering bottle, and the amount of crude oil displaced is measured by the metering bottle.

[0027] The metering piston is reversed by the piston reverse-drive device to displace all the crude oil in the metering bottle into the buffer bottle. Then, the buffer piston is reversed by the piston reverse-drive device to displace all the crude oil in the buffer bottle back into the core sample. Finally, the oil yield of the core sample is measured by the flow channel scale.

[0028] Optionally, the permeation fluid is a surfactant or displacing agent with a certain pore volume, wherein the displacing agent is a liquid or a gas.

[0029] The present invention achieves the following technical effects compared to the prior art:

[0030] The pressure-driven huff and puff device proposed in this invention includes a core percolation device and a connected percolation measurement device. During the simulation and measurement of oil production from pressure-driven huff and puff, it can sequentially measure the initial volume of the liquid displacing agent, the oil production from the core under positive displacement by the liquid displacing agent, and the oil production from the core under reverse displacement by crude oil. This achieves precise measurement of percolation at each stage of the entire pressure-driven huff and puff process. It not only allows for the calculation of oil recovery using the aforementioned measurement data, solving the problem of obtaining accurate experimental data in research and production, but also fills the technological gap in current equipment for measuring percolation during dynamic percolation processes. This invention combines a core percolation device with pressure-driven huff and puff technology, enabling direct high-precision measurement of percolation volume. It can accurately measure percolation during the dynamic percolation process of the core under test, thus solving the problem of the inability to measure dynamic percolation during water injection displacement huff and puff in existing dynamic percolation studies.

[0031] In addition, in some other solutions proposed in this invention, the first flow channel is opened on a transparent bottle, which allows real-time observation of the fluid's action on the core surface during the dynamic percolation process of the core to be tested, thus making the percolation process transparent.

[0032] Furthermore, the pressure-driven huff and puff device proposed in this invention is simple to operate, provides intuitive readings, and offers precise measurement. It can sequentially measure the initial volume of the liquid displacing agent, the oil yield of the core sample under positive displacement by the liquid displacing agent, and the oil yield of the core sample under reverse displacement by crude oil. This achieves precise measurement of the permeation at each stage of the entire pressure-driven huff and puff process. Not only can the above-mentioned measurement data be used to calculate the oil recovery rate, solving the problem of obtaining accurate experimental data in scientific research and production, but it also fills the technological gap in current dynamic permeation process measurement equipment. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the pressure-driven swallowing and puffing device with measurable percolation volume disclosed in an embodiment of the present invention;

[0035] Figure 2A This is a schematic diagram of the core clamping assembly disclosed in the embodiments of the present invention;

[0036] Figure 2B for Figure 2A Axial sectional view;

[0037] Figure 3A This is a schematic diagram of the structure of the limiting cover disclosed in the embodiments of the present invention;

[0038] Figure 3B for Figure 3A Axial sectional view;

[0039] Figure 4A This is a schematic diagram of the structure of the transparent bottle disclosed in the embodiments of the present invention;

[0040] Figure 4B for Figure 4A Axial sectional view;

[0041] Figure 5A This is a schematic diagram of the structure of the extrusion cylinder disclosed in the embodiments of the present invention;

[0042] Figure 5B for Figure 5A Axial sectional view;

[0043] Figure 6A This is a schematic diagram of the annular cover structure disclosed in the embodiments of the present invention;

[0044] Figure 6B for Figure 6A Axial sectional view;

[0045] Figure 7A This is a schematic diagram of the flange connected to the bottom of the annular cover as disclosed in an embodiment of the present invention;

[0046] Figure 7B for Figure 7A Top view;

[0047] Figure 8A This is a schematic diagram of the base structure disclosed in the embodiments of the present invention;

[0048] Figure 8B for Figure 8A Top view;

[0049] Figure 8C for Figure 8A Axial sectional view;

[0050] Figure 9 This is a schematic diagram of the structure of the short screw disclosed in the embodiment of the present invention;

[0051] Figure 10A This is a schematic diagram of the structure of the long screw disclosed in the embodiment of the present invention;

[0052] Figure 10B for Figure 10A Top view;

[0053] Figure 11A This is a schematic diagram of the structure of the buffer bottle disclosed in the embodiments of the present invention;

[0054] Figure 11B for Figure 11A Axial sectional view;

[0055] Figure 11C This is a schematic diagram of the structure of the buffer piston disclosed in the embodiments of the present invention;

[0056] Figure 12A This is a schematic diagram of the structure of the high-precision measuring instrument disclosed in the embodiments of the present invention;

[0057] Figure 12B for Figure 12A Axial sectional view;

[0058] Figure 13A This is a schematic diagram of the structure of the metering bottle disclosed in the embodiments of the present invention;

[0059] Figure 13B for Figure 13A Axial sectional view;

[0060] Figure 14 This is a schematic diagram of the structure of the metering bottle cover disclosed in the embodiments of the present invention;

[0061] Figure 15 This is a schematic diagram of the metering piston disclosed in the embodiments of the present invention;

[0062] Figure 16 This is a schematic diagram of the structure of the metering bottle base disclosed in the embodiments of the present invention;

[0063] Figure 17 This is a schematic diagram of the base screw between the metering bottle base and the metering bottle cover as disclosed in an embodiment of the present invention.

[0064] In the attached diagram, the reference numeral is: 100, a pressure-driven swallowing and puffing device capable of measuring the amount of percolation;

[0065] 1. Core clamping assembly; 101. Extrusion cylinder; 102. Axial extrusion chamber; 103. Annular cover; 104. Closed annular cavity; 105. Second pipeline; 106. Base; 107. Flange; 2. First flow channel; 201. Straight flow channel; 202. Funnel-shaped flow channel; 3. Second flow channel; 4. Core to be tested; 5. Metering bottle; 501. Metering piston; 502. First metering space; 503. Second metering space; 504. Second fluid discharge pipe; 505. First metering fluid pipeline; 506. Second metering fluid pipeline; 6. Piston reverse drive device; 7. Transparent bottle; 8. First pipeline; 9. First 10. Pump; 11. First control valve; 12. Limit cover; 13. Scale line perforation hole; 14. Core perforation hole; 15. Third pipeline; 16. Buffer bottle; 17. Buffer piston; 18. First buffer space; 19. Second buffer space; 10. First fluid discharge pipe; 11. Second control valve; 12. Third control valve; 13. Fourth control valve; 14. Fifth control valve; 15. Sixth control valve; 16. Seventh control valve; 17. Metering bottle cover; 28. Metering bottle base; 29. ​​Short screw; 20. Long screw; 21. Pressure gauge; 22. Base screw; 23. Second pump. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] One of the objectives of this invention is to provide a pressure-driven huff and puff device that can measure the amount of percolation, in order to solve the problem that the dynamic percolation cannot be measured during the water injection displacement huff and puff process in the above-mentioned dynamic percolation research.

[0068] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0069] Example 1

[0070] like Figures 1 to 17 As shown, this embodiment provides a pressure-driven swallowing and plucking device 100 capable of measuring the amount of percolation, mainly including a core percolation device and a percolation measurement device. The core percolation device includes a core clamping assembly 1 for clamping the core to be measured. A first flow channel 2 and a second flow channel 3 are connected to the core clamping assembly 1. The outer surface of one of the first flow channel 2 and the second flow channel 3 is provided with a flow channel scale line for displaying the volume of the percolation fluid. The flow channel is connected to a percolation fluid source, which is used to provide percolation fluid into the core percolation device. The percolation fluid can be a surfactant or a displacing agent with a certain pore volume. The displacing agent can be a liquid or a gas. As a preferred embodiment, the first flow channel 2 is externally connected to an adsorption fluid source. A flow channel scale is provided on the first flow channel 2. The adsorption fluid is injected into the first flow channel 2 and permeates the core sample 4 to be tested in a forward direction. Since the core sample 4 is already saturated with crude oil, the injected adsorption fluid (such as a displacing agent) will displace the crude oil. The displaced crude oil enters the adsorption volume metering device for measurement. Under the same pressure, it is then reversed back into the core sample 4 through the second flow channel 3. The amount of oil produced from the core sample 4 into the first flow channel 2 at this time can be measured through the flow channel scale on the first flow channel 2, thus completing one inflow and outflow process of the adsorption fluid. The terms "forward" and "reverse" for the adsorption fluid are only used to highlight that the two permeation directions are opposite, and are not absolute definitions of "forward" and "reverse." For distinction, terms such as "first" and "second" can also be used.

[0071] In this embodiment, the percolation metering device includes a piston reverse drive device 6, a buffer bottle 13, a buffer piston 1301 disposed within the buffer bottle 13, a graduated metering bottle 5, and a metering piston 501 disposed within the metering bottle 5. The metering piston 501 divides the metering bottle 5 into a first metering space 502 and a second metering space 503. The buffer piston 1301 divides the buffer bottle 13 into a first buffer space 1302 and a second buffer space 1303. One of the first buffer space 1302 and the second buffer space 1303 is simultaneously connected to one of the first metering spaces 502 and the second metering space 503, as well as the aforementioned second flow channel 3. The other of the first buffer space 1302 and the second buffer space 1303, and the other of the first metering space 502 and the second metering space 503, are connected in parallel to the piston reverse drive device 6. Preferably, the first buffer space 1302 and the first metering space 502 are connected, and one end of the first buffer space 1302 is connected to the second flow channel 3. Figure 1The left end shown is connected, and the second buffer space 1303 and the second metering space 503 are connected in parallel to the piston reverse drive device 6. In the actual installation process, the buffer bottle 13 is located between the metering bottle 5 and the permeation metering device. The metering bottle 5 is a transparent metering container and cannot bear pressure. The buffer bottle 13 has the effect of pressure buffering and can bear pressure. Therefore, the crude oil displaced in the core 4 to be tested is first displaced into the buffer bottle 13, and then all the crude oil is displaced into the metering bottle 5 for metering (read through the scale line of the metering bottle 5). Then, the crude oil is displaced back into the buffer bottle 13. Finally, with the same displacement pressure (the same pressure as the crude oil displaced in the core 4 to be tested) and a certain displacement speed, the crude oil is displaced back into the core 4 to be tested. The core 4 to be tested discharges oil into the first flow channel 2, and the amount of oil discharged is measured through the scale line of its flow channel (i.e., read through the scale line of the flow channel). The fluid displacement power from buffer bottle 13 to metering bottle 5, from metering bottle 5 to buffer bottle 13, and from buffer bottle 13 to core 4 is all derived from piston reverse drive device 6. When the first buffer space 1302 or the first metering space 502 is filled with fluid (such as crude oil), the fluid can be discharged by pushing the buffer piston 1301 or metering piston 501 in the direction of squeezing the first buffer space 1302 or the first metering space 502 through piston reverse drive device 6, thus providing displacement power for the fluid.

[0072] In this embodiment, the core percolation device specifically includes a transparent bottle 7 connected to the core clamping assembly 1. A first flow channel 2 is formed inside the transparent bottle 7. One end of the first flow channel 2 is connected to the aforementioned percolation fluid source via a first pipe 8, and the other end is connected to one axial end of the core 4 to be tested. A first pump 9, a first control valve 10, and a pressure gauge 24 are connected to the first pipe 8. The first pump 9 can pump the surfactant or displacing agent in the percolation fluid source into the core 4 to be tested. Preferably, the transparent bottle 7 is cylindrical, and the core 4 to be tested is cylindrical and coaxially arranged with the transparent bottle 7. Of course, the core 4 to be tested is saturated with formation water and then saturated with crude oil to simulate the state of a natural reservoir. In actual operation, the core 4 to be tested can also be a square core or a core of other shapes.

[0073] In this embodiment, the first flow channel 2 includes a straight flow channel 201 and a funnel-shaped flow channel 202 arranged coaxially therewith. The first flow channel 2 is formed on the axis of the transparent bottle 7. One end (top) of the straight flow channel 201 is connected to the first pipe 8, and the other end (bottom) is connected to the small end of the funnel-shaped flow channel 202. The large end of the funnel-shaped flow channel 202 is aligned with the end of the core sample 4 to be tested, that is, the large end of the funnel-shaped flow channel 202 abuts against the end of the core sample 4 to be tested. Preferably, the diameter of the large end of the funnel-shaped flow channel 202 is the same as or slightly larger than the diameter of the cross-section of the core sample 4 to be tested. At the same time, the end face of the large end of the funnel-shaped flow channel 202 is in contact with the top face of the extrusion cylinder 101 described below, which can buffer the fluid pressure.

[0074] In this embodiment, a limiting cover 11 is fitted over the outside of the transparent bottle 7. The limiting cover 11 is a cylindrical cover with a closed top and an open bottom, and is inverted and placed over the outside of the transparent bottle 7. The outer surface of the transparent bottle 7 is provided with the aforementioned flow channel scale lines. The limiting cover 11 has perforated holes for displaying the flow channel scale lines and the rock core 4 to be tested. The perforated holes for displaying the flow channel scale lines are scale line perforated holes 1101, and the perforated holes for displaying the rock core 4 to be tested are rock core perforated holes 1102. Multiple scale line perforated holes 1101 are provided. Preferably, each scale line perforated hole 1101 displays a different scale. The multiple scale line perforated holes 1101 are arranged in rows at intervals along the axial direction of the transparent bottle 7. The outer wall of the transparent bottle 7 is provided with two rows of scale line perforated holes 1101, and the two rows of scale line perforated holes 1101 are symmetrically distributed at 180°. Correspondingly, the core perforation 1102 is a triangular perforation, serving as an "observation window." A core perforation 1102 is formed at the bottom of each row of graduation line perforations 1101, with the tip of the core perforation 1102 spaced apart from the adjacent graduation line perforation 1101 above it. The larger end of the core perforation 11 penetrates the bottom edge of the limiting cover 11, thus forming a notch at the bottom of the limiting cover 11. Through the aforementioned graduation line perforations 1101 and core perforations 1102, the limiting cover 11 allows direct reading of the graduations on the transparent bottle 7 and direct observation of the oil seepage process on the core surface.

[0075] In this embodiment, the transparent bottle 7 is made of transparent glass, and its overall structure can be considered as a cylindrical solid glass with fine channels carved out inside. The limiting cover 11 is preferably a cylindrical metal cover with a top, an opening at the bottom, and a protrusion extending outward. The protrusion has multiple screw holes for connection with the extrusion cylinder 101 described below. The limiting cover 11 covers the outer wall of the transparent bottle 7, limiting the outer periphery of the transparent bottle 7 and ensuring that the transparent bottle 7 can withstand greater pressure.

[0076] In this embodiment, the core clamping assembly 1 mainly includes a compression cylinder 101, an annular cover 103, and a base 106. An axial compression cavity 102 is coaxially formed inside the compression cylinder 101, and one end (top) of the core sample 4 to be tested is placed inside the axial compression cavity 102. The end of the compression cylinder 101 containing the core sample 4 is connected to a transparent bottle 7. The annular cover 103 is fitted over the outside of the compression cylinder 101, forming a closed annular cavity 104 with the outer wall of the compression cylinder 101. A second pipe 105 communicating with the closed annular cavity 104 is formed on the side wall of the annular cover 103, and a second pump 26 is connected to the second pipe 105 to pump fluid into the closed annular cavity 104. A confining pressure simulation fluid is introduced to make the extrusion cylinder 101 clamp the rock core 4 to be tested. The confining pressure simulation fluid is generally water. After the closed annular cavity 104 is filled with water, it can not only simulate the confining pressure of the rock layer, but also compress the extrusion cylinder 101 in a circumferential direction, so that the extrusion cylinder 101 clamps the rock core 4 to be tested. The base 106 is sealed at the other end (bottom end) of the axial extrusion cavity 102 and abuts against the other end (bottom end) of the axial extrusion cylinder 4 to support the rock core 4 to be tested. The second flow channel 3 is opened in the base 106, and one end of the second flow channel 3 is connected to the end of the rock core 4 to be tested, and the other end is connected to the permeation measurement device through the third pipe 12. As a preferred embodiment, the base 106 includes a chassis and a sealing shaft. The sealing shaft is connected to the center of the chassis and is used to extend through the bottom end of the axial compression chamber 102 until it abuts against the bottom end of the core sample 4 to be tested. After the sealing shaft is inserted into the axial compression chamber 102, the chassis can be connected to the upper annular cover 103 by a long screw 23. By rotating and adjusting the long screw 23, the distance between the chassis and the upper annular cover 103 can be adjusted to adjust the axial length of the sealing shaft extending into the axial compression chamber 102, which can meet the support requirements of core samples 4 with different axial lengths. At the same time, the second flow channel 3 is divided into a vertical section and a horizontal section. The vertical section is set through the axis of the sealing shaft, while the horizontal section is opened along the radial direction of the chassis. The vertical section and the horizontal section intersect perpendicularly, thereby forming a right-angle (corner) structure of the second flow channel 3. The aforementioned core clamping assembly 1 can expose the core 4 to be tested within the visible range of the core perforation 1102, making it easy to see with the naked eye during rock seepage simulation experiments, and to observe the seepage process on the surface of the core 4 to be tested, further solving the problem of not being able to obtain accurate experimental data in scientific research and production.

[0077] In this embodiment, the annular cover 103 is preferably a metal cover with strong pressure-bearing capacity. Both axial ends of the extrusion cylinder 101 are provided with flange connection end faces, with an "I"-shaped cross-section. The annular cover 103 is fitted over the outside of the extrusion cylinder 101 and located between the flange connection end faces at both ends of the extrusion cylinder 101. The inner wall of the annular cover 103 is radially recessed outward to form an annular concave surface. This annular concave surface is used to fit the side wall of the extrusion cylinder 101 to form a closed annular cavity 104, as shown in Figures 2 to 8. The edge of the limiting cover 11, the flange connection end face at the top of the extrusion cylinder 101, and the annular... The top surface of the cover 103 is fixed with screws; a flange 107 is also provided at the bottom of the annular cover 103. The flange 107, the flange connection end face at the bottom of the extrusion cylinder 101, and the bottom end face of the annular cover 103 are fixed with screws. Correspondingly, the base plate of the aforementioned base 106 is connected to the flange 107 by a long screw 23. By adjusting the length of the long screw 23 screwed into or out of the flange 107, the axial length of the sealing shaft extending into the axial extrusion chamber 102 can be adjusted. The extrusion cylinder 101 is preferably a rubber cylinder, which can hold the rock core 4 under simulated confining pressure. The inner wall shape of the extrusion cylinder 101 changes according to the shape of the rock core 4. For example, if the rock core 4 is cylindrical, the inner wall of the extrusion cylinder 101 is cylindrical; if the rock core 4 is prismatic, the inner wall of the extrusion cylinder 101 is also set to prismatic.

[0078] In this embodiment, one end of the aforementioned third pipeline 12 is connected to the second flow channel 3, and the other end is connected to the first buffer space 1302 of the buffer bottle 13. A second control valve 14 is provided between the third pipeline 12 and the first buffer space 1302, and a third control valve 15 is provided on the connecting pipeline between the first buffer space 1302 and the first metering space 502; a fourth control valve 16 is provided on the connecting pipeline between the second buffer space 1303 and the piston reverse drive device 6, and a fifth control valve 17 is provided on the connecting pipeline between the second metering space 503 and the piston reverse drive device 6. Simultaneously, this embodiment also provides a first fluid discharge pipe 1304 and a second fluid discharge pipe 504, wherein the first fluid discharge pipe 1304 is connected between the second buffer space 1303 and the piston reverse drive device 6, and a sixth control valve 18 is provided on the first fluid discharge pipe 1304; the second fluid discharge pipe 504 is connected between the second metering space 503 and the piston reverse drive device 6, and a seventh control valve 19 is provided on the second fluid discharge pipe 504.

[0079] In this embodiment, the percolation measurement device further includes a measuring bottle cover 20 and a measuring bottle base 21. The measuring bottle cover 20 is fitted over the measuring bottle 5, and the bottom of the measuring bottle cover 20 is fixedly connected to the measuring bottle base 21 by multiple base screws 25. For example... Figure 1 and Figure 12BAs shown, a first metering fluid pipeline 505 is provided through the top of the metering bottle 5 and the top of the metering bottle cover 20, and the first metering fluid pipeline 505 is connected to the third pipeline 12; a second metering fluid pipeline 506 is provided through the bottom of the metering bottle 5, the bottom of the metering bottle cover 20, and the metering bottle base 21106, and the piston reverse drive device 6 and the second fluid discharge pipe 504 are connected in parallel to the second metering fluid pipeline 506. The metering bottle cover 20 covers the outside of the metering bottle 5 and is used to limit the outer periphery of the metering bottle 5 to improve the pressure bearing capacity of the metering bottle 5.

[0080] In this embodiment, the piston reverse drive device 6 is preferably an air pump or a water pump.

[0081] In this embodiment, a control system can be provided. The first control valve 10, second control valve 14, third control valve 15, fourth control valve 16, fifth control valve 17, sixth control valve 18, and seventh control valve 19 are all preferably solenoid valves, and each solenoid valve is communicatively connected to the control system to control the opening and closing of each solenoid valve. Simultaneously, to ensure the safety of equipment operation, pressure gauges 24 can be installed on any of the connecting pipelines where the solenoid valves are installed, such as on the first pipeline 8, the second pipeline 105, and the third pipeline 12, etc. The specific number and location of the pressure gauges can be referenced. Figure 1 As shown. Furthermore, in order to improve the automation level of equipment operation, each pressure gauge 24 is communicatively connected to the aforementioned control system so that the control system can receive the pressure signals of each pressure gauge 24 in real time and issue an alarm when the pressure exceeds the limit (threshold).

[0082] The following section uses the pressure-driven huff and puff device 100, which is described above as having a measurable percolation capacity, as an example to simulate the oil production from pressure-driven huff and puff. The working principle and process are explained in detail below. The percolation fluid is preferably an existing liquid displacement agent, and the core sample 4 is already saturated with crude oil (operated using existing methods).

[0083] First, close all control valves, namely the first control valve 10, the second control valve 14, the third control valve 15, the fourth control valve 16, the fifth control valve 17, the sixth control valve 18, and the seventh control valve 19. After inserting the core sample 4 to be tested into the top of the extrusion cylinder 101, install the base 106 and make the top of the sealing shaft of the base 106 contact the bottom end face of the core sample 4 to be tested. Then, start the second pump 26 to start injecting water into the internal space of the closed annular cavity 104 to create confining pressure, so that the extrusion cylinder 101 tightly holds the core sample 4 to be tested. After the closed annular cavity 104 is filled with water, turn off the second pump 26.

[0084] Then, the first control valve 10 and the second control valve 14 are opened, and the first pump 9 is started simultaneously to deliver liquid displacing agent into the transparent glass bottle 7 (i.e., the first flow channel 2). The initial volume value of the liquid displacing agent is read through the flow channel scale on the first flow channel 2. The liquid displacing agent permeates from the top to the bottom of the core sample 4 and displaces the crude oil in the core sample 4. The displaced crude oil flows out of the base 106 through the second flow channel 3. The top of the base 106 is threaded to ensure that all the displaced crude oil flows into the second flow channel 3 in the base 106 without residue, until all the displaced crude oil flows into the first buffer space 1302 of the buffer bottle 13 through the third pipeline 12.

[0085] Subsequently, to determine the amount of crude oil displaced, further measurement is required. Therefore, the crude oil needs to be sent to metering bottle 5 for measurement. This involves closing the second control valve 14, opening the fourth control valve 16 and the third control valve 15, and then starting the third pump (i.e., the piston reverse drive device 6, which can be an air pump or a water pump). Preferably, the third pump is an air pump, which delivers gas into the second buffer space 1303 of the buffer bottle 13. Due to the pressure difference between the first buffer space 1302 and the second buffer space 1303, the buffer piston 1301 in the buffer bottle 13 moves upward (i.e., moves in the direction of reducing the volume of the first buffer space 1302), squeezing all the crude oil in the first buffer space 1302 out of the buffer bottle 13. The crude oil then enters the first metering space 502 of the metering bottle 5 through the third control valve 15. The sixth control valve 18 is then opened to purge the gas from the second buffer space 1303 of the buffer bottle 13, and the sixth control valve 18 and the fourth control valve 16 are then closed. At this time, the crude oil is located in the first metering space 502. By observing the movement of the metering piston 501 from when the crude oil enters until it stops moving, the stroke of the metering piston 501 along the scale line is obtained and the volume of crude oil is recorded. Since the metering bottle 5 cannot withstand pressure, the crude oil needs to be reversed and driven back into the buffer bottle 13. At this time, the fifth control valve 17 is opened and the aforementioned third pump (i.e., piston reverse drive device 6) is started to deliver gas into the second metering space 503. Due to the pressure difference between the first metering space 502 and the second metering space 503, the metering piston 501 in the metering bottle 5 moves upward (i.e. moves in the direction of reducing the volume of the first metering space 502), squeezing all the crude oil in the first metering space 502 out of the metering bottle 5. The crude oil is then squeezed back into the first buffer space 1302 of the buffer bottle 13 through the third control valve 15.

[0086] Next, the seventh control valve 19 is opened to purge the gas from the second metering space 503, and the fifth control valve 17 and the seventh control valve 19 are closed. Then the third control valve 15 is closed, and the second control valve 14 and the fourth control valve 16 are opened. The aforementioned third pump is then turned on again to deliver gas into the second buffer space 1303 of the buffer bottle 13. Due to the pressure difference between the first buffer space 1302 and the second buffer space 1303, the buffer piston 1301 in the buffer bottle 13 moves upward (i.e., moves in the direction of reducing the volume of the first buffer space 1302), squeezing the crude oil in the first buffer space 1302 out of the buffer bottle 13. The crude oil then enters the third pipeline 12 in reverse through the second control valve 14, and then returns to the base 106 through the second flow channel 3. During the process of crude oil being reverse-driven from the first buffer space 1302 to the base 106, it is important to note that the crude oil pressure should be the same as when the crude oil is discharged from the base 106 through the second flow channel 3. The crude oil is driven back to the test core 4 through the second flow channel 3 and permeates in reverse from the bottom to the top of the test core 4. During the process of crude oil driving back to the test core 4, oil is produced at the top of the test core 4. The amount of oil produced can be read from the flow channel scale line on the first flow channel 2, and the oil production status can be directly observed through the core hollow hole 1102.

[0087] After all the crude oil in the first buffer space 1302 is squeezed into the base 106, the third pump and the second control valve 14 are closed, the sixth control valve 18 is opened, the gas in the second buffer space 1303 of the buffer bottle 13 is purged, and the sixth control valve 18 and the fourth control valve 16 are closed to complete one throughput cycle and the percolation measurement.

[0088] Because pressure-driven huff and puff are greatly affected by the type, amount, and rate of the displacing agent, the pressure-driven huff and puff visualization device with measurable percolation capacity disclosed in this technical solution can simulate the huff and puff production characteristics of tight oil reservoirs.

[0089] In the process of simulating and measuring the oil production of the pressure-driven huff and puff device 100, which can measure the permeation, the initial volume of the liquid displacing agent, the oil production of the test core 4 under the positive displacement of the liquid displacing agent, and the oil production of the test core 4 under the reverse displacement of crude oil were measured in sequence. This achieved accurate measurement of the permeation at each stage of the entire pressure-driven huff and puff process. Not only can the above-mentioned measurement data be used to calculate the oil recovery rate (using the existing calculation method), solving the problem that scientific research and production cannot obtain accurate experimental data, but it also fills the technical gap in the current dynamic permeation process permeation measurement equipment.

[0090] Meanwhile, the pressure-driven flow visualization device disclosed in this technical solution, capable of measuring percolation, allows observation of the core surface during pressure driving and enables visual observation during rock seepage simulation experiments. It facilitates direct observation of the percolation process on the core surface, providing a more intuitive understanding of the experimental process. This technical solution combines a visual core clamping assembly with a high-precision metering device; their synergistic effect achieves transparency in the percolation process and results, while maintaining high measurement accuracy.

[0091] Example 2

[0092] In addition to the function of metering the oil production from pressure-driven huff and puff as described in Embodiment 1 above, the pressure-driven huff and puff device 100 of this technical solution, which can meter the amount of seepage, can also meter seepage-derived oil to calculate the recovery rate of seepage-derived oil. "Seepage," also called self-absorption, refers to the process where, without displacement pressure, a displacing agent (water or surfactant) is automatically drawn into the core to drive out crude oil, driven by capillary force. In measuring seepage-derived oil, the core sample 4 used simulates the state of a natural reservoir, i.e., saturated with formation water before being saturated with crude oil.

[0093] The transparent bottle 7 has a visible structure and flow channel graduations, allowing real-time observation of the oil droplets on the surface of the core 4 under test through the core perforation 1102. It also allows for precise measurement of spontaneous adsorption oil production (oil-water density difference). Since the pressure-driven huff and puff device 100 of this technical solution is based on pressure-driven huff and puff technology, it can also measure smaller displacement pressures (must be lower than capillary force; the specific displacement direction is from the buffer bottle 13 to the second flow channel 3, and then to the core 4 under test; see details). Figure 1 The spontaneous percolation production (marked by the solid black arrow) refers to the oil production produced through percolation, which must be spontaneous.

[0094] 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 that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0095] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A pressure drive huff and puff device capable of metering the amount of imbibition, characterized by, The application relates to a core imbibition device and an imbibition volume metering device. The core imbibition device comprises a core clamping assembly for clamping a core to be measured; a first flow channel and a second flow channel are connected to the core clamping assembly; an outer surface of one of the first flow channel and the second flow channel is provided with flow channel scale lines for displaying the volume of fluid, and a source of imbibition fluid is connected to the outer surface to introduce the imbibition fluid into the core to be measured. The imbibition volume metering device comprises a buffer bottle and a metering bottle with scale lines; a buffer piston is arranged in the buffer bottle, and the buffer piston divides the buffer bottle into a first buffer space and a second buffer space; a metering piston is arranged in the metering bottle, and the metering piston divides the metering bottle into a first metering space and a second metering space; one of the first buffer space and the second buffer space is connected to one of the first metering space and the second metering space and the other of the first flow channel and the second flow channel; the other of the first buffer space and the second buffer space and the other of the first metering space and the second metering space are connected to a piston counter driving device; and the metering bottle is used for metering the volume of fluid in the buffer bottle.

2. The pressure-driven huff and puff device of claim 1, wherein, The core imbibition device comprises a transparent bottle connected to the core clamping assembly; the first flow channel is arranged in the transparent bottle, one end of the first flow channel is connected to the source of imbibition fluid through a first pipeline, and the other end is connected to one end of the core to be measured. The first pipeline is connected to a first pump and a first control valve.

3. The pressure-driven huff and puff device of claim 2, wherein, The first flow channel comprises a straight flow channel and a funnel-shaped flow channel coaxially arranged with the straight flow channel; one end of the straight flow channel is connected to the first pipeline, the other end is connected to a small end of the funnel-shaped flow channel, and a large end of the funnel-shaped flow channel is connected to the end of the core to be measured.

4. The pressure-driven huff and puff device of a quantifiable imbibition amount according to claim 2 or 3, characterized in that, The transparent bottle is externally sleeved with a limiting cover; the outer surface of the transparent bottle is provided with the flow channel scale lines, and the limiting cover is provided with a hollow hole for displaying the flow channel scale lines and the core to be measured.

5. The pressure-driven huff and puff device of claim 4, wherein, The core clamping assembly comprises: An extrusion cylinder, an axial extrusion cavity is arranged in the extrusion cylinder, and the core to be measured is arranged at one end in the axial extrusion cavity; the end of the extrusion cylinder provided with the core to be measured is connected to the transparent bottle; A ring-shaped cover, the ring-shaped cover is sleeved on the outside of the extrusion cylinder, and a closed ring-shaped cavity is formed between the ring-shaped cover and the outer wall of the extrusion cylinder; a second pipeline is arranged in the side wall of the ring-shaped cover and is connected to the closed ring-shaped cavity, so that the confining pressure simulation fluid is introduced into the closed ring-shaped cavity, and the extrusion cylinder tightly holds the core to be measured; A base, the base is arranged at the other end in the axial extrusion cavity and abuts against the other end of the core to be measured; the second flow channel is arranged in the base, one end of the second flow channel is connected to the end of the core to be measured, and the other end is connected to one of the first buffer space and the second buffer space through a third pipeline.

6. The pressure-driven huff and puff device of claim 5, wherein, The buffer bottle is located between the metering bottle and the imbibition metering device, the first buffer space and the first metering space are connected in parallel to one end of the third pipeline away from the second flow channel, the second buffer space and the second metering space are connected in parallel to the piston counter driving device; and a second control valve is arranged between the third pipeline and the first buffer space, a third control valve is arranged between the first buffer space and the first metering space; a fourth control valve is connected between the second buffer space and the piston counter driving device, and a fifth control valve is connected between the second metering space and the piston counter driving device.

7. The pressure-driven huff and puff device of claim 6, wherein, The first fluid discharge pipe and the second fluid discharge pipe are further included, wherein the first fluid discharge pipe is connected in parallel between the second buffer space and the piston counter driving device, and a sixth control valve is arranged on the first fluid discharge pipe; the second fluid discharge pipe is connected in parallel between the second metering space and the piston counter driving device, and a seventh control valve is arranged on the second fluid discharge pipe.

8. The pressure discharge huff and puff device of any one of claims 1 to 3, wherein, The imbibition metering device further includes a metering bottle cover and a metering bottle base, the metering bottle cover is sleeved outside the metering bottle, and the bottom of the metering bottle cover is fixedly connected with the metering bottle base.

9. The pressure discharge huff and puff device of any one of claims 1 to 3, wherein, The piston counter driving device is a gas pump or a water pump.

10. A method for using the pressure discharge huff and puff device based on the quantifiable imbibition amount according to any one of claims 1 to 9, characterized in that, The method comprises: The imbibition fluid is introduced into one of the first flow channel and the second flow channel with the flow channel scale line, and the initial amount of imbibition fluid is metered through the flow channel scale line; The imbibition fluid penetrates into the measured core and displaces the crude oil in the measured core; the crude oil displaced in the measured core enters the buffer bottle for receiving; then the buffer piston is counter driven by the piston counter driving device to displace the crude oil in the buffer bottle into the metering bottle, and the amount of displaced crude oil is metered by the metering bottle; The metering piston is counter driven by the piston counter driving device to displace the crude oil in the metering bottle into the buffer bottle, then the buffer piston is counter driven by the piston counter driving device to displace the crude oil in the buffer bottle back into the measured core, and finally the oil output of the measured core is metered through the flow channel scale line. The imbibition metering device further includes a metering bottle cover and a metering bottle base, the metering bottle cover is sleeved outside the metering bottle, and the bottom of the metering bottle cover is fixedly connected with the metering bottle base. The piston counter driving device is a gas pump or a water pump. The method comprises: The imbibition fluid is introduced into one of the first flow channel and the second flow channel with the flow channel scale line, and the initial amount of imbibition fluid is metered through the flow channel scale line; The imbibition fluid penetrates into the measured core and displaces the crude oil in the measured core; the crude oil displaced in the measured core enters the buffer bottle for receiving; then the buffer piston is counter driven by the piston counter driving device to displace the crude oil in the buffer bottle into the metering bottle, and the amount of displaced crude oil is metered by the metering bottle; The metering piston is counter driven by the piston counter driving device to displace the crude oil in the metering bottle into the buffer bottle, then the buffer piston is counter driven by the piston counter driving device to displace the crude oil in the buffer bottle back into the measured core, and finally the oil output of the measured core is metered through the flow channel scale line.

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