Fluid-rock reaction apparatus and experimental method considering stress sensitivity

Abstract

The embodiment of the application provides a fluid-rock reaction device and experimental method considering stress sensitivity. The device comprises a reaction container, a core rubber sleeve and a sealing assembly. The inside of the reaction container is provided with a fluid cavity for simulating fluid pressure and an annular pressure cavity for simulating formation stress. The side wall of the reaction container is provided with an annular pressure interface for connecting the annular pressure cavity with an external annular pressure pump, a test fluid interface for connecting the fluid cavity and a test fluid outlet. The core rubber sleeve is arranged in the annular pressure cavity and is used for accommodating a rock sample to be tested. The sealing assembly comprises a first sealing member and a second sealing member, which respectively seal an annular space between the core rubber sleeve and the annular pressure cavity and a second end surface of the rock sample away from the fluid cavity. Based on the stress sensitivity factor, the degree of fluid-rock interaction under different ground stress conditions, different temperatures and fluid pressure conditions is researched, and the fluid-rock interaction experiment on real oil and gas natural rock samples is carried out, thereby providing guidance for parameter optimization of oil and gas reservoir fracturing technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas storage, and particularly relates to a fluid-rock reaction device and experimental method considering stress sensitivity. BACKGROUND

[0002] The unconventional oil and gas reservoirs in China have the characteristics of tightness, high crude oil viscosity and poor flowability, and a large-scale horizontal well volume fracturing reconstruction technology is used to construct a long-term fracture network with a flow conductivity, which greatly reduces the flow resistance of crude oil and is a key to realize long-term stable production of unconventional oil and gas wells. A large number of studies have shown that fluid-rock interaction caused by the entry of fracturing fluid into the formation has a significant influence on the effectiveness of the fracture. The influence of different fluid-rock interactions on the effectiveness of the fracture is related to the efficient development of unconventional oil and gas.

[0003] However, the traditional fluid-rock interaction experiment usually does not consider the influence of the ground stress, the rock is not stressed, and the water-sensitive rock is easy to be loose and broken, so it does not conform to the actual situation of the reservoir, the accuracy of the experimental results is not high, the reliability is poor, and reliable data and support cannot be provided for the conventional and unconventional oil and gas reservoir stimulation and production increase. SUMMARY

[0004] The embodiment of the present application provides a fluid-rock reaction device and experimental method considering stress sensitivity, which can accurately consider the interaction between fluid and reservoir rock under the condition of formation stress, accurately simulate the interaction between fluid and reservoir rock under the condition of formation stress, and provide reliable data and technical support for conventional and unconventional oil and gas reservoir stimulation and production increase.

[0005] In a first aspect, the embodiment of the present application provides a fluid-rock reaction device considering stress sensitivity, which comprises:

[0006] A reaction container, an inner part of the reaction container is provided with a fluid cavity and a ring pressure cavity, the fluid cavity is used for simulating fluid pressure, the ring pressure cavity is used for simulating formation stress, a side wall of the reaction container is provided with a ring pressure interface, a test fluid interface and a test fluid outlet, the test fluid interface is used for connecting the fluid cavity with an external liquid injection pump, so that the liquid injection pump injects fluid into the fluid cavity through the test fluid interface, and the ring pressure interface is used for connecting the ring pressure cavity with an external ring pressure pump, so that the ring pressure pump applies ring pressure to the ring pressure cavity through the ring pressure interface;

[0007] A core rubber sleeve, the core rubber sleeve is arranged in the ring pressure cavity and is used for accommodating a rock sample to be tested;

[0008] A blocking assembly includes a first blocking member for sealing an annular space between the core sleeve and the hoop stress chamber and for connecting the rock sample to be tested to the fluid chamber at a first end surface of the fluid chamber, and a second blocking member for sealing a second end surface of the rock sample to be tested away from a second end surface of the fluid chamber so as to isolate the second end surface of the rock sample to be tested from an external space of the core sleeve.

[0009] In a possible implementation, the reaction container further comprises a mounting rack for mounting the reaction container, the mounting rack is provided with two bearing seats, the bearing seats are provided with bearings, and the reaction container is rotatably mounted to the bearing seats through a rotating shaft and the bearings.

[0010] In a possible implementation, the reaction container comprises a fluid reservoir and a holder, the fluid reservoir is provided with a blocking chamber and the fluid chamber in communication, and the holder is provided with a hoop stress chamber and a blocking assembly mounting chamber in communication.

[0011] The reaction container further comprises a third blocking member, a fourth blocking member, and at least two sealing members, the third blocking member is arranged in the blocking chamber and used for blocking the blocking chamber and a middle space of the fluid chamber, the fourth blocking member is arranged in a second positioning step of the blocking assembly mounting chamber and used for blocking the blocking assembly mounting chamber, the hoop stress interface is arranged in the fourth blocking member, the test fluid interface and the test fluid outlet are arranged in the fluid reservoir, and the sealing members are arranged on an outer circumferential surface of the hoop stress chamber mounting portion and an outer circumferential surface of the fourth blocking member.

[0012] In a possible implementation, an outer circumferential surface of a front end of the fourth blocking member is provided with a plug-in portion, and an inner portion of a rear end of the core sleeve is provided with a plug-in matching portion, the plug-in portion is used for being plugged into the inner portion of the plug-in matching portion to axially limit the core sleeve.

[0013] In a possible implementation, a front end surface of the plug-in portion is a conical surface, and the plug-in matching portion is provided with a conical groove for matching the conical surface.

[0014] In a possible implementation, an inner portion of the reaction container is provided with a connecting wall for spacing the fluid chamber and the front end hoop stress chamber, the connecting wall is provided with a conical sealing surface on a side located at the front end cavity, and a front end of the core sleeve is provided with a conical end surface matched with the conical sealing surface.

[0015] In a possible implementation, the third blocking member comprises a third core plug, a second pressure cap sleeved on the third core plug, and a sealing ring for sealingly connecting the third core plug and the fluid reservoir.

[0016] In a possible implementation, the fourth sealing member comprises a nipple for pressing the second sealing member, a plug rod inserted into the nipple, a fourth sealing plug sleeved on the nipple, a second pressure cap for locking the fourth sealing plug, and a third pressure cap for locking the plug rod.

[0017] In a possible implementation, the fluid reservoir is made of stainless acid-resistant steel.

[0018] In a second aspect, the embodiments of the present application provide an experimental method, applied to the fluid-rock reaction device considering stress sensitivity, and comprising the following steps:

[0019] The core is processed into a rock sample with a preset specification;

[0020] The rock sample is loaded into a core rubber sleeve, and the core rubber sleeve loaded with the rock sample is loaded into a hoop stress cavity of a reaction container, a second sealing member is installed in the core rubber sleeve, and a first sealing member is installed in an annular space between the sealing core rubber sleeve and the hoop stress cavity in the hoop stress cavity;

[0021] The hoop stress pump is connected to the hoop stress interface, and a hoop stress is applied to the hoop stress cavity through the hoop stress interface;

[0022] The injection pump is connected to the test fluid interface, the test fluid outlet is closed, and a fluid pressure is applied to the fluid cavity through the test fluid interface;

[0023] The reaction container is placed in an oven, reaction temperature and reaction time are set, and a fluid-rock reaction is performed;

[0024] The reaction container is taken out of the oven, and after cooling, the test fluid outlet is opened, the hoop stress is unloaded, and the core is taken out;

[0025] The core and the test fluid are subjected to physical property testing.

[0026] The fluid-rock reaction device considering stress sensitivity and the experimental method provided by the embodiments of the present application can perform mineral composition testing, solution ion testing, rock mechanics testing, and other tests by setting a reaction container, the reaction container being provided with a fluid cavity and a hoop stress cavity, the fluid cavity being connected to an external injection pump through a test fluid interface, the injection pump being used to inject a test fluid into the fluid cavity and apply a fluid pressure, the reaction temperature, the reaction time, and other reaction parameters being set by placing the reaction container in an oven, and the degree of action of a fluid on a rock under reaction temperature and time conditions being simulated.

[0027] The fluid-rock reaction device and experimental method considering stress sensitivity provided in the application can study the fluid-rock interaction degree under different stress conditions, different fluid pressure conditions, different types of fluids and different temperature conditions based on factors such as in-situ stress, fluid pressure, fluid type and temperature, and thus carry out fluid-rock interaction experiments on real oil and gas natural rock samples considering factors such as in-situ stress, fluid pressure and temperature, so as to obtain the influence data of different types of fracturing fluids on reservoir rocks and judge the influence degree of fracturing fluid on fracture surface, natural fracture or laminations, thereby providing guidance for parameter optimization of oil and gas reservoir fracturing process. In addition, the application has simple structure, compact layout, simple and efficient operation in the whole experimental process and is easy to implement, truly simulates the action environment of fracturing fluid and reservoir rock in the field fracturing process, and the test result has high accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0028] The drawings incorporated into the specification and forming a part thereof show embodiments consistent with the application and, together with the specification, serve to explain the principles of the application.

[0029] Figure 1 A cross-sectional view of the fluid-rock reaction device considering stress sensitivity provided for a specific embodiment of the application;

[0030] Figure 2 For Figure 1 A cross-sectional view of the fluid-rock reaction device considering stress sensitivity in the embodiment, circumscribing the liquid injection pump and the hoop stress pump;

[0031] Figure 3 A flowchart of the experimental method provided in the application.

[0032] BRIEF DESCRIPTION OF DRAWINGS:

[0033] 10 - reaction container; 20 - core rubber sleeve; 30 - plugging assembly; 40 - liquid injection pump; 50 - hoop stress pump; 60 - rock sample;

[0034] 11 - fluid reservoir; 12 - gripper;

[0035] 101 - fluid cavity; 102 - hoop stress cavity; 103 - hoop stress interface; 104 - test fluid interface; 105 - test fluid outlet; 106 - connecting wall; 111 - plugging cavity; 121 - plugging assembly mounting cavity; 201 - plug-in fitting part; 202 - conical end face; 301 - first plugging piece; 302 - second plugging piece; 303 - third plugging piece; 304 - fourth plugging piece; 305 - sealing piece;

[0036] 1061 - conical sealing surface; 1211 - second positioning step; 2011 - conical groove; 3031 - third core plug; 3032 - first pressure cap; 3033 - sealing ring; 3041 - spigot; 3042 - conical surface; 3043 - adapter; 3044 - plug rod release; 3045 - fourth sealing plug; 3046 - second pressure cap; 3047 - third pressure cap.

[0037] The specific embodiments of the application have been shown by way of example in the above figures, and will be described in more detail hereafter. These drawings and the written description are not intended to restrict the scope of the application in any way but are merely illustrative of specific embodiments of the application as presently contemplated. DETAILED DESCRIPTION

[0038] Reference will now be made to the drawings in which the exemplary embodiments of present application will be discussed. The following description with reference to the drawings is not meant to limit the scope of the application in any way but is merely meant to illustrate the principles of the application as presently contemplated.

[0039] It should be noted that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "connected directly" or "fixed directly" to another element or layer, there are no intervening elements or layers present. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] In addition, the terms "first", "second", etc. are used herein only to describe various elements, but do not imply or suggest relative importance or a quantity of the indicated elements. Thus, features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0041] In the present application, unless otherwise specifically limited and defined, the "on", "under", "above", and "over" of a first element to a second element can mean that the first element is in direct contact with the second element or indirectly in contact with the second element through an intermediate medium. Moreover, the "above", "over", and "on" of a first element to a second element can mean that the first element is directly above or obliquely above the second element, or only means that the first element is directly below or obliquely below the second element, or only means that the first element is horizontally lower than the second element.

[0042] Unless otherwise defined, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application solely for the purpose of describing a specific embodiment of the present application, and is not intended to be limiting of the present application. The term "and / or" used in the specification of the present application includes any and all combinations of one or more of the associated listed items.

[0043] Considering that the existing fluid-rock interaction experiment usually does not consider the influence of factors such as ground stress, fluid stress, fluid type, temperature, etc., cannot truly simulate the fluid-rock reaction environment, the rock is not stressed, the water-sensitive rock is easy to loosen and break, and does not conform to the actual situation of the reservoir, thereby resulting in low experimental precision and poor reliability of experimental data.

[0044] Based on the limitations of the traditional fluid-rock interaction experiment and the complexity of the environment of the oil and gas natural rock, and considering that the fluid-rock reaction experiment does not consider the influence of factors such as ground stress, fluid stress, fluid medium type, temperature, etc., cannot simulate the actual situation of the reservoir, and thus has poor experimental precision, low reliability, and limited application range, the present application proposes a fluid-rock reaction device and experimental method considering stress sensitivity, which can carry out fluid-rock interaction experiment considering the ground stress of real oil and gas natural rock sample, and can simulate the fluid-rock interaction degree experiment under different ground stress conditions, different temperatures, different fluid types, and different fluid pressure conditions, so as to obtain the influence of different types of fracturing fluid on the reservoir rock, judge the influence degree of the fracturing fluid on the fracture surface, natural fracture / crust, etc., and provide data guidance and support for the optimization of conventional or unconventional oil and gas reservoir fracturing process parameters.

[0045] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0046] Please refer to Figure 1 and Figure 2The embodiment of the present application provides a fluid and rock reaction device considering stress sensitivity, mainly comprising a reaction container 10, a core rubber sleeve 20 and a sealing assembly 30. The inside of the reaction container 10 is provided with a fluid cavity 101 and a hoop stress cavity 102, the side wall of the reaction container 10 is provided with a hoop stress interface 103, a test fluid interface 104 and a test fluid outlet 105, the hoop stress interface 103 is communicated with the hoop stress cavity 102, and the test fluid interface 104 and the test fluid outlet 105 are both communicated with the fluid cavity 101. The outside injection pump 40 is communicated with the fluid cavity 101 through the test fluid interface 104, so that the injection pump 40 injects fluid into the fluid cavity 101 through the test fluid interface 104, and the outside hoop stress pump 50 is communicated with the pressure cavity through the hoop stress interface 103, so as to ensure that the hoop stress pump 50 applies hoop stress to the hoop stress cavity 102 through the hoop stress interface 103.

[0047] The core rubber sleeve 20 is a sleeve body with open ends and a closed outer periphery, and the inside of the core rubber sleeve 20 is provided with an inner cavity, the shape and size of the inner cavity are set according to the shape and size of the rock sample to be tested, for example, when a cylindrical rock sample 60 is used, the inner cavity of the core rubber sleeve 20 is provided as a circular cross section; when a strip-shaped rock sample 60 is used, the inner cavity of the core rubber sleeve 20 can be provided as a square cross section or a rectangular cross section. Therefore, the shape and size of the core rubber sleeve 20 and the inner cavity thereof are not limited herein, as long as the rock sample 60 can be installed.

[0048] The core rubber sleeve 20 is arranged in the hoop stress cavity 102 and is detachably installed in the cavity of the hoop stress cavity 102, and the two ends thereof are sealed by the sealing assembly 30. The sealing assembly 30 comprises a first sealing piece 301 and a second sealing piece 302, the annular space between the core rubber sleeve 20 and the hoop stress cavity 102 is sealed by the first sealing piece 301, and the first end surface of the rock sample to be tested facing the fluid cavity 101 is ensured to be communicated with the fluid cavity 101. The second end surface of the rock sample to be tested away from the fluid cavity 101 is sealed by the second sealing piece 302, so that the second end surface of the rock sample to be tested is isolated from the outer space of the core rubber sleeve 20.

[0049] In other words, the two ends of the core rubber sleeve 20 are sealed by the first sealing piece 301 and the second sealing piece 302 respectively. Specifically, a connecting wall 106 is arranged between the fluid cavity 101 and the hoop stress cavity 102, the first sealing piece 301 seals the outer end surface of the core rubber sleeve 20 on the side facing the fluid cavity 101 and the connecting wall 106, so that the end surface of the rock sample to be tested in the core rubber sleeve 20 is exposed to the fluid cavity 101, the test rock sample 60 contacts the test fluid, and the rock sample 60 is a porous medium, which realizes self-suction synchronous with the reaction by capillary force or relying on capillary force and power as a power source.

[0050] The second blocking member 302 seals the inner cavity of the other end of the core rubber sleeve 20, so as to ensure that the test fluid completely enters the rock sample to be tested without leakage, thereby ensuring that the test fluid completely reacts with the test rock sample 60.

[0051] It should be noted that the fluid in the present application can include gas and liquid, including but not limited to supercritical CO2, water, CO2 aqueous solution, hydrochloric acid, etc.

[0052] The fluid-rock reaction device considering stress sensitivity provided in the present application realizes the analysis of the reaction degree of fluid and reservoir rock based on stress sensitivity conditions, and the working principle is that the comprehensive simulation of fluid-rock interaction experiments under different formation stresses, different fluid pressures and different temperatures is realized by applying the hoop stress to the hoop stress cavity 102 and injecting the test fluid into the fluid cavity 101, thereby significantly improving the experimental accuracy.

[0053] In order to meet the experimental requirements of different installation angles, a mounting rack can be arranged at the bottom of the reaction container 10, which mainly includes a base, a connecting frame and a placing table. The base is arranged on the experimental platform or the ground, the reaction container 10 is placed on the placing table, and the connecting frame is vertically connected between the base and the placing table to connect the placing table to the base. Two bearing seats are arranged on the mounting rack, and the two bearing seats are symmetrically arranged on the placing table. The bearing seat is provided with a bearing, and the two ends of the reaction container 10 are provided with rotating shafts which are coaxially arranged. The end of the rotating shaft extends into the bearing and is rotatably installed in the bearing seat.

[0054] The reaction container 10 is rotatably installed in the bearing seat through the rotating shaft and the bearing, so as to realize the adjustment of the installation angle of the reaction container 10, support the horizontal placement, vertical placement and placement at a certain inclination angle relative to the placing table of the reaction container 10.

[0055] When the reaction container 10 is placed in the vertical direction or at an angle, the rock sample 60 inside the reaction container 10 is vertically arranged, which takes capillary force and gravity as the pumping power, so that the test fluid quickly enters the inside of the rock sample 60, the wetting power is greater, the fluid loss can be reduced, and the reaction efficiency is improved. When the reaction container 10 is placed in the vertical direction and the fluid cavity 101 faces upward, the wetting power is the largest, the fluid loss is the smallest, and the reaction efficiency is the highest.

[0056] It can be understood that the reaction container 10 in the present embodiment can be rotatably installed, and the placement angle can be adjusted arbitrarily according to experimental requirements.

[0057] Further, the reaction container 10 adopts a split structure, including a fluid reservoir 11 and a holder 12, the inside of the fluid reservoir 11 is provided with a blocking cavity 111 and a fluid cavity 101, both cavities are communicated, the inside of the holder 12 is provided with a ring pressure cavity 102 and a blocking assembly installation cavity 121, both cavities are communicated, and the blocking cavity 111, the fluid cavity 101, the ring pressure cavity 102 and the blocking assembly installation cavity 121 are coaxially arranged and communicated from one end to the other end of the reaction container 10.

[0058] The reaction container 10 further includes a third blocking piece 303, a fourth blocking piece 304 and at least two sealing pieces 305. Among them, the third blocking piece 303 is arranged in the blocking cavity 111, the middle space of the blocking cavity 111 and the fluid cavity 101 is blocked through the third blocking piece 303, the inner wall of the blocking assembly installation cavity 121 is provided with a second positioning step 1211, the fourth blocking piece 304 is arranged in the blocking assembly installation cavity 121 and is positioned and installed through the second positioning step 1211, and the blocking assembly installation cavity 121 inside the holder 12 is sealed by the fourth blocking piece 304. In addition, the sealing piece 305 is arranged on the outer circumferential surface of the ring pressure cavity 102 installation part and the outer circumferential surface of the fourth blocking piece 304. In this way, the fluid cavity 101 and the ring pressure cavity 102 form a sealed space separated from the outside of the reaction device. The test fluid interface 104 and the test fluid outlet 105 are arranged on the fluid reservoir 11. The external liquid injection pump 40 is connected through the test fluid interface 104, the fluid enters the fluid cavity 101, and from the middle space of the fluid cavity 101, it enters the pores of the rock sample 60, and gradually enters the rock sample 60 while reacting with the rock sample 60. The external ring pressure pump 50 is connected through the ring pressure interface 103, and different formation stresses can be simulated.

[0059] In this application, the ring pressure cavity 102 is used to simulate the formation stress, which can simulate any value of the ground stress in the range of 0-80 MPa. The fluid cavity 101 is used to simulate the fluid pressure, which can simulate any value of the fluid pressure in the range of 0-60 MPa, and related fluid rock interaction experiments can be carried out.

[0060] In a specific embodiment, a plug-in part 3041 can be arranged on the fourth blocking piece 304, which is arranged on the front end outer circumferential surface of the fourth blocking piece 304. Correspondingly, a plug-in matching part 201 is arranged inside the rear end of the core rubber sleeve 20. When assembled, the plug-in part 3041 is inserted into the inside of the plug-in matching part 201, and the axial positioning is realized through the mating surface of the two, so as to realize the axial limiting of the core rubber sleeve 20.

[0061] In order to improve the sealing performance of the fourth blocking member 304 and the core rubber sleeve 20, the front end surface of the plug-in part 3041 is a tapered surface 3042, and the inside of the plug-in fitting part 201 is provided with a tapered groove 2011 which is adapted to the tapered surface 3042, thereby increasing the contact area through the contact slope, so as to ensure the sealing effect of the core rubber sleeve 20 and the connecting end of the fourth blocking member 304.

[0062] Since the inside of the reaction container 10 is provided with the connecting wall 106 which separates the fluid cavity 101 and the front end ring pressure cavity 102 and positions the core rubber sleeve 20, in order to improve the sealing performance between the core rubber sleeve 20 and the connecting wall 106, the connecting wall 106 is provided with a tapered sealing surface 1061 on one side of the front end cavity, and the front end surface of the core rubber sleeve 20 is provided with a tapered end surface 202 which is adapted to the tapered sealing surface 1061 of the connecting wall 106, and the two form a tapered sealing surface 1061, so as to improve the sealing effect between the core rubber sleeve 20 and the connecting wall 106.

[0063] Specifically, the third blocking member 303 includes a third core plug 3031, a first pressure cap 3032 sleeved on the third core plug 3031, and a sealing ring 3033 sealingly connecting the third core plug 3031 and the fluid reservoir 11.

[0064] Specifically, the fourth blocking member 304 includes a connector 3043 for pressing the second blocking member 302, a plug rod 3044 inserted into the inside of the connector 3043, a fourth sealing plug 3045 sleeved on the connector 3043, a second pressure cap 3046 for locking the fourth sealing plug 3045, and a third pressure cap 3047 for locking the plug rod 3044.

[0065] In order to prevent the fluid from corroding the fluid cavity 101 inside the reaction device during the reaction of the fluid and the rock, thereby causing the fluid cavity 101 to lose the sealing performance, the material of the fluid cavity 101 is preferably but not limited to stainless acid-resistant steel material. It should be noted that the specific material of the fluid reservoir 11 and the fluid cavity 101 inside it can be various, and is not limited herein.

[0066] The sealing ring 3033 in the present application can be but is not limited to a sealing ring made of fluororubber material. Since the fluororubber material has excellent high-temperature resistance and chemical corrosion resistance, it can ensure that the fluororubber maintains stable sealing performance under extreme conditions and prolongs the service life of the sealing ring 3033.

[0067] In summary, the fluid and rock reaction device considering stress sensitivity provided in the application can comprehensively consider factors such as stress, fluid pressure, fluid medium type, and temperature, simulate the action environment of fracturing fluid and reservoir rock in the field fracturing process, and carry out fluid-rock interaction experiments on the rock. The whole experimental process is simple, fast, efficient, highly reliable, accurate, and easy to implement.

[0068] Reference Figure 3 The application also provides an experimental method applied to the fluid and rock reaction device considering stress sensitivity, which comprises the following steps:

[0069] Step S1: processing the rock sample into a rock sample of a predetermined specification;

[0070] Step S2: loading the rock sample into a core rubber sleeve, and loading the core rubber sleeve with the rock sample into a ring pressure cavity of a reaction container, installing a second sealing member in the core rubber sleeve, and installing a first sealing member in an annular space between the sealing core rubber sleeve and the ring pressure cavity in the ring pressure cavity;

[0071] Step S3: connecting a ring pressure pump to a ring pressure interface to apply ring pressure to the ring pressure cavity to simulate the formation stress;

[0072] Step S4: connecting a liquid injection pump to a test fluid interface, closing a test fluid outlet, and applying fluid pressure to the fluid cavity through the liquid injection pump;

[0073] Step S5: placing the reaction container in an oven, setting the reaction temperature and reaction time, and performing fluid-rock reaction;

[0074] Step S6: taking the reaction container out of the oven, cooling, opening the test fluid outlet, unloading the ring pressure, and taking out the core;

[0075] Step S7: performing physical property testing on the core and the test fluid.

[0076] The core in the application can be an irregular oil and gas reservoir rock sample in an oil and gas reservoir. In step S1, the irregular oil and gas reservoir rock sample is processed into a regular core that meets the core bin specification of the water-rock reaction device, as a rock sample to be tested. The shape of the test rock sample can be, but is not limited to, a cylinder, for example, a strip or an irregular shape.

[0077] In step S2, after the rock sample is sleeved in the core rubber sleeve, the core rubber sleeve with the rock sample is placed in the ring pressure cavity, and the left and right sides of the core rubber sleeve are placed in the sealing member, which can be a sealing plug.

[0078] In step S3, the hydraulic pump is connected to the ring pressure interface to apply ring pressure to simulate the formation stress.

[0079] In step S4, the test fluid is connected to the test fluid inlet and the test fluid outlet is closed, and the fluid pressure is applied by the injection pump.

[0080] In step S5, the reaction container is placed in the oven to set the reaction temperature and reaction time, and after the reaction time is reached, the reaction container is taken out of the oven, cooled, and the test fluid outlet is opened, the ring pressure is unloaded, and the rock sample is taken out.

[0081] In step S6, a series of physical property tests are performed on the rock sample and the test fluid, and the degree of fluid-rock reaction is analyzed.

[0082] The following describes the experimental method described above, with an example of a simulated ground stress of 50 MPa, a fluid pressure of 30 MPa, a test fluid of CO2 aqueous solution, and a reaction time of 24 hours, as follows:

[0083] Step S1: irregular oil and gas reservoir rock sample 60 is processed into a regular cylindrical core that meets the specifications of the water-rock reaction device core chamber: a rock sample 60 with a diameter of 2.5 cm and a length of 5 cm;

[0084] Step S2: the rock sample to be tested is sleeved into the core rubber sleeve 20 and placed in the ring pressure chamber 102, and the first sealing member 301 and the second sealing member 302 are sealed at the left and right ends of the core rubber sleeve 20;

[0085] Step S3: the hydraulic pressure is connected to the ring pressure interface 103 to apply a ring pressure of 50 MPa to simulate the ground stress;

[0086] Step S4: the test fluid CO2 aqueous solution is connected to the test fluid inlet, and the test fluid outlet 105 is closed, and the fluid pressure is applied by the injection pump 40 to 30 MPa;

[0087] Step S5, Step S6: the reaction container 10 is placed in the oven to set the reaction temperature, and after the reaction time of 24 hours is reached, the test fluid outlet 105 is opened, the fluid pressure is unloaded; the ring pressure interface 103 is opened, the ring pressure is unloaded, and the rock sample 60 is taken out;

[0088] Step S7: a series of physical property tests are performed on the rock sample 60 and the test fluid, including but not limited to mineral composition testing, solution ion testing, rock mechanics testing, etc., to analyze the degree of fluid-rock reaction.

[0089] It should be understood that many of the materials and devices exemplified in this disclosure are articles of manufacture (i.e., articles of manufacture) according to this disclosure. The articles of manufacture can be manufactured as such or can be manufactured by combining the materials and devices exemplified in this disclosure. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It should be understood that, in some embodiments, equivalents to the specific electrode structures and / or methods described herein can be employed without departing from the scope of the application. Accordingly, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," "containing," "involving," "characterized by," "characterized into," and variations thereof herein, is meant to encompass the items listed thereafter, and equivalents thereof as well as additional items. Although the foregoing application has been described in some detail by way of illustration and example, it is not to be limited thereby, but rather, only by the scope of the appended claims.

Claims

1. A fluid-rock reaction device considering stress sensitivity, characterized in that, include: The reaction vessel (10) has a fluid chamber (101) and an annular pressure chamber (102) inside. The fluid chamber (101) is used to simulate fluid pressure, and the annular pressure chamber (102) is used to simulate formation stress. The side wall of the reaction vessel (10) is provided with an annular pressure interface (103), a test fluid interface (104), and a test fluid outlet (105). The test fluid interface (104) is used to connect the fluid chamber (101) with an external injection pump (40) so that the injection pump (40) injects fluid into the fluid chamber (101) through the test fluid interface (104). The annular pressure interface (103) is used to connect the annular pressure chamber (102) with an external annular pressure pump (50) so that the annular pressure pump (50) applies annular pressure to the annular pressure chamber (102) through the annular pressure interface (103). Core sleeve (20), the core sleeve (20) is disposed in the annular compression cavity (102) and is used to contain the rock sample to be tested; The reaction vessel (10) has a connecting wall (106) inside to separate the fluid cavity (101) and the annular pressure cavity (102). The connecting wall (106) has a conical sealing surface (1061) on one side of the cavity. The front end of the core sleeve (20) has a conical end face (202) adapted to the conical sealing surface (1061). A sealing assembly (30) is provided, which includes a first sealing element (301) and a second sealing element (302). The first sealing element (301) is used to seal the fluid cavity (101) and the annular pressure cavity (102). The outer end face of the core sleeve (20) facing the fluid cavity (101) is sealed with the connecting wall (106) to seal the annular space between the core sleeve (20) and the annular cavity (102) and to make the first end face of the rock sample to be tested facing the fluid cavity (101) connected to the fluid cavity (101). The second sealing member (302) is used to seal the second end face of the rock sample to be tested away from the fluid cavity (101) so that the second end face of the rock sample to be tested is isolated from the external space of the core sleeve (20). It also includes a mounting bracket for mounting the reaction vessel (10), the mounting bracket having two bearing seats with built-in bearings, the reaction vessel (10) being rotatably mounted on the bearing seats via a rotating shaft and the bearings to achieve adjustment of the installation angle of the reaction vessel.

2. The stress-sensitive fluid-rock reaction device according to claim 1, characterized in that, The reaction vessel (10) includes a fluid reservoir (11) and a clamp (12). The fluid reservoir (11) is provided with a connected sealing cavity (111) and a fluid cavity (101). The clamp (12) is provided with a connected ring pressure cavity (102) and a sealing component mounting cavity (121). The reaction vessel (10) further includes: a third plugging member (303), a fourth plugging member (304), and at least two sealing members (305), wherein the third plugging member (303) is disposed in the plugging cavity (111) for sealing the middle space of the plugging cavity (111) and the fluid cavity (101), the fourth plugging member (304) is disposed in the second positioning step (1211) of the plugging assembly mounting cavity (121) for sealing the plugging assembly mounting cavity (121), the ring pressure interface (103) is disposed in the fourth plugging member (304), the test fluid interface (104) and the test fluid outlet (105) are disposed in the fluid reservoir (11), and the sealing member (305) is disposed on the outer peripheral surface of the mounting part of the ring pressure cavity (102) and the outer peripheral surface of the fourth plugging member (304).

3. The stress-sensitive fluid-rock reaction device according to claim 2, characterized in that, The fourth sealing component (304) has a plug-in portion (3041) on its front outer peripheral surface, and the core sleeve (20) has a plug-in mating portion (201) inside its rear end. The plug-in portion (3041) is used to be inserted into the plug-in mating portion (201) to axially limit the core sleeve (20).

4. The stress-sensitive fluid-rock reaction device according to claim 3, characterized in that, The front end face of the plug-in part (3041) is a conical surface (3042), and the plug-in mating part (201) is provided with a conical groove (2011) for adapting to the conical surface (3042).

5. The stress-sensitive fluid-rock reaction device according to claim 2, characterized in that, The third sealing component (303) includes a third core plug (3031), a first pressure cap (3032) fitted onto the third core plug (3031), and a sealing ring (3033) that seals the third core plug (3031) and the fluid reservoir (11).

6. The stress-sensitive fluid-rock reaction apparatus according to any one of claims 2 to 4, characterized in that, The fourth sealing member (304) includes a sleeve (3043) for pressing against the second sealing member (302), a plug removal rod (3044) inserted inside the sleeve (3043), a fourth sealing plug (3045) fitted onto the sleeve (3043), a second pressure cap (3046) for locking the fourth sealing plug (3045), and a third pressure cap (3047) for locking the plug removal rod (3044).

7. The stress-sensitive fluid-rock reaction apparatus according to any one of claims 2 to 4, characterized in that, The fluid storage device (11) is a stainless acid-resistant steel fluid storage device.

8. An experimental method applied to the stress-sensitive fluid-rock reaction apparatus according to any one of claims 1 to 7, characterized in that, Including the following steps: The core samples are processed into rock samples of a predetermined size; The rock sample is loaded into the core sleeve, and the core sleeve containing the rock sample is then placed into the annular cavity of the reaction vessel. A second sealing element is installed in the core sleeve, and a first sealing element is installed in the annular space between the sealed core sleeve and the annular cavity. Connect the ring pressure pump to the ring pressure interface, and apply ring pressure simulating formation stress to the ring pressure chamber through the ring pressure interface; Connect the injection pump to the test fluid interface, close the test fluid outlet, and apply fluid pressure to the fluid chamber through the test fluid interface; The reaction vessel was placed in an oven, and the reaction temperature and reaction time were set to carry out the fluid-rock reaction. Remove the reaction vessel from the oven, allow it to cool, open the test fluid outlet, unload the ring pressure, and remove the core. Physical properties of the core sample and the test fluid were tested.

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