High-temperature and high-pressure simulation device and method for clay mineral conversion in shale diagenesis process

Abstract

The invention relates to the technical field of clay mineral conversion in the shale diagenesis process, in particular to a high-temperature and high-pressure simulation device and method for clay mineral conversion in the shale diagenesis process. The device comprises a diagenesis hydrocarbon generation reaction kettle unit, a temperature and pressure control unit, a fluid injection and liquid permeability detection unit, a gas-liquid separation, collection, metering and detection unit, a gas injection and discharge and permeability detection unit and a computer control unit. According to the application, various factors influencing the diagenesis, such as temperature, pressure, oxygen-free environment, relationship between various fluids and the diagenesis, flow state of the fluids, rock porosity and permeability change, fluid ion concentration change, hydrocarbon generation and hydrocarbon expulsion, clay mineral evolution and the like, are comprehensively considered, and the simulation experiment is more in line with geological reality; according to the reaction kettle, gas-liquid products are effectively separated, the sealing performance of the reaction kettle is detected before an experiment, the experiment success rate is increased, and meanwhile, a proper stirring speed is set, so that the stability of an experiment result is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of clay mineral conversion in shale diagenesis, and specifically to a high-temperature and high-pressure simulation device and method for clay mineral conversion in shale diagenesis. Background Art

[0002] In recent years, with advances in oil and gas geological theory and exploration and development technologies, shale oil has become a key unconventional resource in China, possessing immense strategic significance. This has driven a series of important theoretical advances in shale diagenesis research. However, relatively few experimental devices and technologies are available for diagenesis. Existing diagenesis and clay mineral conversion technologies, both domestically and internationally, primarily target conventional and tight oil, focusing on sandstone and carbonate rocks. Even fewer experimental devices and technologies are available for clay mineral conversion during shale diagenesis, severely hindering research on in situ shale oil diagenesis and clay mineral conversion and in situ reservoir formation.

[0003] Diagenesis is inextricably linked to the evolution of hydrocarbon generation and expulsion from organic matter and fluid-rock interactions. The evolution of clay minerals in organic matter and the division of diagenetic stages are crucial components of diagenetic research. Integrating diagenesis, fluid-rock interaction, clay mineral transformation, and hydrocarbon generation and expulsion geological processes helps to accurately capture subsurface diagenetic processes. Advances in unconventional oil and gas exploration theory have revealed that mudstones, previously thought to be incapable of forming reservoirs, contain nanoscale reservoir spaces. Therefore, changes in porosity and permeability during diagenetic evolution have become crucial aspects of shale diagenetic evolution research.

[0004] At present, the main diagenetic simulation experimental devices include the "Diagenesis Simulation Experimental Device" (patent announcement number CN102411044B) developed by China University of Petroleum (East China). This device has the functions of simulating the diagenetic effect of various fluids on rocks when they are in dynamic and static contact with rocks under high temperature and high pressure conditions, simulating and testing the influence of compaction on the diagenetic process, dynamically monitoring the changes in core permeability, porosity and fluid composition, and the maximum simulation temperature is 300°C; the "An Underground Diagenetic Simulation Device" (patent announcement number CN105845010A) developed by China University of Geosciences (Wuhan) can set different temperature, pressure, solid and fluid medium conditions, quantitatively collect fluid and solid products, simulate hydrocarbon generation and expulsion processes, and study pore evolution. The "Hot-Pressure Simulation Experimental Device for the Whole Process of Rock Formation, Hydrocarbon Generation and Expulsion" (Patent Announcement No. CN102733801B) invented by China National Petroleum Corporation can simulate hydrocarbon expulsion methods such as slow seepage, episodic transient flow, and steady-state flow, isolate reactants and discharges, achieve temperature control and upper, middle and lower pipeline design, meet all hydrocarbon expulsion combination modes, and are designed with anti-blocking function.

[0005] However, the above-mentioned diagenetic simulation device has the following shortcomings: First, it does not take into account the particularity of the mudstone diagenesis process. Unlike sandstone, mudstone, as a source rock, will produce a large amount of hydrocarbons under high temperature and high pressure conditions. During the diagenetic simulation process, gaseous products are discharged along with the diagenetic fluid. The composition of these gases includes combustible gases of C1-C5 and toxic and harmful H2S and CO. If not treated, they will endanger the experimental environment and the health of the operators. At the same time, the collected hydrocarbon gas can also be used for hydrocarbon generation research. If it is not processed, it will cause a waste of resources; secondly, the existing devices have not considered the reactor sealing inspection and vacuum measures before the experiment, resulting in the discovery of reactor leakage and changes in the simulated geological environment in the middle of the experiment; thirdly, there are no anti-precipitation measures for the diagenetic mineral fluid injected into the reactor. Long-term mineral precipitation will affect the concentration of the injected fluid and thus change the experimental results; at the same time, the present application takes into account that if the stirring speed in the anti-precipitation fluid container 301 is too slow, the precipitate and the liquid cannot be fully mixed, which will cause the fluid concentration to fluctuate; and if the stirring speed is too fast, the liquid surface will cause significant fluctuations, which will cause the optical liquid level device 303 to be unable to accurately read the liquid level information, affecting the normal operation of the fluid replenishment mechanism; at the same time, if the stirring speed is too fast, local high-speed eddy currents will be generated, which may cause bubbles to be generated in the liquid, and will also affect subsequent liquid concentration measurements. Summary of the Invention

[0006] In order to solve the above technical problems, this application provides a high-temperature and high-pressure simulation device and method for clay mineral transformation in the shale diagenesis process. The technical solutions adopted are as follows:

[0007] In a first aspect, an embodiment of the present application provides a high-temperature and high-pressure simulation device for clay mineral conversion during shale diagenesis, the device comprising a diagenetic hydrocarbon generation reactor unit 100, a temperature and pressure control unit 200, a fluid injection and liquid permeability detection unit 300, a gas-liquid separation, collection, metering and detection unit 400, a gas injection and permeability detection unit 500, and a computer control unit 600;

[0008] The diagenetic hydrocarbon generation reactor unit 100 is located inside the temperature and pressure control unit 200. The fluid injection and liquid permeability detection unit 300 is connected to one side of the upper overburden pressure plug tee 105 of the diagenetic hydrocarbon generation reactor unit 100. The gas-liquid separation, collection, metering, and detection unit 400 is connected to one side of the lower support plug tee 115. The gas injection, discharge, and permeability detection unit 500 is divided into an introduction mechanism 5001 and an extraction mechanism 5002.

[0009] Among them, the introduction mechanism 5001 is connected to the other side of the three-way hole 105 of the upper covering pressure plug, and the lead-out mechanism 5002 is connected to the other side of the three-way hole 115 of the lower supporting plug. Each unit is connected to the computer control unit 600.

[0010] Preferably, the diagenetic hydrocarbon generation reactor unit 100 includes: a high-pressure sleeve 101, a sample chamber 102, a high-pressure reactor body 103, an upper pressure threaded cap 104, an upper covering pressure plug three-way hole 105, an upper covering pressure plug 106, an upper pressure pad 107, a sealing component A108, an upper filter 109, a lower filter 110, a sealing component B111, a lower threaded barrel 112, a sealing component C113, a lower support plug 114, a lower support plug three-way hole 115, a lower threaded pressure cap 116, a lower pressure pad 117, a semicircular vibration plate 118, and a locking cap 119.

[0011] Preferably, the sample chamber 102 is a space formed by the high-pressure sleeve 101 , the upper filter 109 and the lower filter 110 .

[0012] Preferably, the upper part of the autoclave body 103 is provided with an overlying pressure plug 106 for applying overlying pressure. The plug is composed of two upper and lower sections of cylinders of different lengths, and contains an overlying pressure plug three-way hole 105 with through holes in three directions. One side of the coarse cylindrical body of the plug is fitted with the upper filter plate 109 and is built into the high-pressure sample cylinder 101. One side of the thin cylindrical body of the plug passes through the sealing component A108, the upper pressure pad 107, and the locking cap 119 from bottom to top, wherein the locking cap 119 is threadedly connected to the overlying pressure plug 106 for compacting the upper pressure pad 107 and the sealing component A108.

[0013] Preferably, the lower support plug 114 is composed of four parts: a thin cylinder, a middle cylinder, a flat-top cone and a thick cylinder. The lower support plug has a three-way hole 115 with through holes in three directions. There is an annular groove on the thin cylinder, and an annular sealing component C113 is arranged in the groove. The outer side of the lower part of the middle cylinder has a thread and can be connected to the lower threaded barrel 112. The thin diameter part of the lower support plug 114 passes through the trapezoidal sealing component B111 and the lower pressure pad 117 in sequence. The lower threaded barrel 112 and the lower threaded pressure cap 116 are cylindrical and consist of two hollow circles of different diameters from top to bottom along their axis. The upper hollow circle has a thread inside, and its inner diameter is the same as the outer diameter of the autoclave body 103. The lower hollow circle passes through the cylinder, and its inner diameter is the same as the outer diameter of the thin diameter part of the lower support plug 114. The lower threaded pressure cap 116 is used to support the autoclave body 103, the high-pressure sleeve 101, the lower threaded barrel 112 and the lower support plug 114.

[0014] Preferably, the semicircular vibration plate 118 is composed of two semicircular vibration plates, which fit tightly against the autoclave body 103 and are used to knock on the vibration plate to generate micro-vibration, so that the water in the sample chamber can completely penetrate into the rock before heating and pressurizing. It must be disassembled before heating and pressurizing.

[0015] Preferably, the temperature and pressure control unit 200 includes: a heating system 201, a lower pressure cylinder 202, and an upper pressure cylinder 203; the upper pressure cylinder 203 and the lower pressure cylinder 202 both have a plug displacement measurement function.

[0016] Preferably, the fluid injection and liquid permeability detection unit 300 includes: an anti-sedimentation fluid container 301, an agitator 302, a light-sensing liquid level meter 303, a fluid container cover 304, a fluid replenishing container 305, a fluid booster pump 306, a booster A307, a preheating system 308, a pressure sensor A309, a valve A310, and a valve K311.

[0017] Preferably, the anti-precipitation fluid container 301 is made of a transparent material, and has an agitator 302 at the bottom thereof for periodic stirring to prevent solute precipitation in the mineral solution in the container and maintain a stable solute concentration.

[0018] Preferably, the optical liquid level sensor 303 is fixed at a position higher than the agitator 302 outside the anti-sedimentation fluid container 301 and is used to monitor the liquid level change; when the liquid in the anti-sedimentation fluid container (301) is lower than the lower limit position of the optical liquid level sensor (303), the valve (K311) automatically opens, and the liquid in the fluid replenishment container (305) flows into the anti-sedimentation fluid container (301); when the liquid is higher than the upper limit position of the optical liquid level sensor (303), the valve (K311) automatically closes, thereby realizing the replenishment injection of the fluid.

[0019] Preferably, the fluid container cover 304 is above the anti-sedimentation fluid container 301 for dust prevention. It has two circular holes through which the fluid replenishment pipeline and the lead-out pipeline pass. The positions of the two pipelines are higher than the agitator 302 but lower than the light-sensing liquid level meter 303.

[0020] Preferably, the gas-liquid separation, collection, metering and detection unit 400 includes: valve B401, pressure sensor B402, automatic control valve 403, back pressure device 404, back pressure pump 405, valve C406, gas-liquid separation tank 407, cold trap A408, gas collection meter 409, valve D410, pressure relief pipe 411, separation baffle A412, liquid receiving cup 413, electronic balance 414, ion concentration detector 415, valve E416, gas-liquid separation funnel 417, separation baffle B418, cold trap B419, and negative pressure gas collector A420.

[0021] Preferably, one side of the back pressure device 404 is connected to the automatic control valve, and the other side has two branches. The first branch is connected to the valve C406, the gas-liquid separation tank 407, and the gas collection meter 409 in sequence, wherein the gas collection meter 409 is inside the cold trap A408; the second branch is connected to the valve D410, the pressure relief pipe 411 and the gas-liquid separation funnel 417 in sequence, wherein the pressure relief pipe is a pipeline with a larger inner diameter, which is used to reduce the fluid pressure entering the gas-liquid separation funnel 417.

[0022] Preferably, the gas-liquid separation funnel 417 is placed inside the cold trap B419. The separatory funnel has downwardly inclined separation baffles A412 and B418. A small hole is provided on the top of the separatory funnel, which is connected to the negative pressure gas collector A420 through a pipeline. The bottom of the separatory funnel is funnel-shaped, and the bottom and the small hole can be extended to the liquid receiving cup 413 through a pipeline.

[0023] Among them, the separation baffle B418 is above the separation baffle A412, one side of which is tightly fitted with the inner wall of the gas-liquid separation funnel 417, and the other side extends obliquely downward and has a small gap with the separation baffle A412, allowing liquid to flow downward; one side of the separation baffle A412 is tightly fitted with the inner wall of the gas-liquid separation funnel 417, and the other side extends obliquely downward and retains a small gap with the inner wall of the gas-liquid separation funnel 417, allowing liquid to flow downward; there is a valve E416 between the gas-liquid separation funnel 417 and the liquid receiving cup 413.

[0024] Preferably, the gas injection and permeability detection unit 500 includes: valve F501, pressure sensor C502, valve G503, booster B504, gas booster pump 505, pressure reducing valve 506, valve H507, gas cylinder 508, valve I509, pressure sensor D510, gas flow meter 511, negative pressure gas collector B512, valve J513, vacuum system 514; it can be used for airtightness testing, anaerobic environment simulation and gas permeability measurement.

[0025] Secondly, the present application also provides a high-temperature and high-pressure simulation method for clay mineral transformation during shale diagenesis. When measuring the liquid permeability and fluid ion concentration of a rock sample, the stirring speed of the stirrer 302 is adjusted and controlled based on the changes in the permeability data, ion concentration data, and liquid level data of the liquid in the anti-sedimentation fluid container 301 during each collection cycle. The method includes the following steps:

[0026] S1, respectively obtain the permeability data, ion concentration data and liquid level data of the liquid in the anti-sedimentation fluid container 301 through the pressure sensor A309, the ion concentration detector 415 and the optical liquid level sensor 303;

[0027] S2, analyzing the distribution characteristics of the peak values ​​in the ion concentration data collected in each acquisition cycle, the slope estimation of the ion concentration data, and the chaotic distribution characteristics between the means of the ion concentration data divided into multiple subsequences, and determining the slow confidence of each acquisition cycle;

[0028] S3, determining the over-rapid confidence level for each acquisition cycle based on the distribution characteristics of the peak values ​​in the permeability data collected in each acquisition cycle, the average levels of the autocorrelation coefficients of the permeability data at different lag orders, and the data distribution characteristics after the second-order difference of the liquid level data collected in each acquisition cycle;

[0029] S4, taking the difference between the slow confidence and the too fast confidence as the speed adjustment confidence of the corresponding acquisition cycle;

[0030] S5, using the comparison result of the speed adjustment confidence and the preset confidence threshold, as well as the slow confidence, the too fast confidence and the stirring speed of the stirrer 302, determine the adjustment index of the stirrer 302 in each collection cycle; and correct the stirring speed of the stirrer 302 in the current collection cycle to be stirred.

[0031] Preferably, the rock sample comprises rock, clay or kerogen, clay minerals.

[0032] Preferably, the slowness confidence of each acquisition cycle is determined by the product of the distribution characteristics of the peak value of the concentration data in the corresponding acquisition cycle, the slope estimate, and the chaotic distribution characteristics between the means.

[0033] Preferably, in step S2, the distribution characteristics of the peak values ​​are further determined as the product of the variance of the peak values ​​and the number of peak values ​​in the concentration data.

[0034] Preferably, the data distribution characteristics after the second-order difference of the liquid level data include:

[0035] Calculate the average level of all differential values ​​after the second-order difference of the liquid level data collected in each collection cycle;

[0036] Using the median of the second-order difference of the liquid level data collected in each collection cycle, all difference values ​​are divided into the pre-sequence and post-sequence;

[0037] Calculate the sum of the slopes and the absolute value of the differences of the linear fitting results of the pre-sequence and post-sequence respectively;

[0038] Calculate the product of the summation result and the absolute value of the difference;

[0039] The data distribution characteristics after the second-order difference of the liquid level data are determined by the average level of all the difference values ​​and the sum of the product results.

[0040] Preferably, in step S3, the method for determining the over-speed confidence level of each acquisition cycle is:

[0041] Calculating the ratio of the autocorrelation coefficient at different lag orders to the distribution characteristics of the peak value in the permeability data;

[0042] The ratio of the data distribution characteristics after the second-order difference of the liquid level data and the ratio is used as the over-speed confidence of each acquisition cycle.

[0043] Preferably, the method for determining the adjustment index of the stirrer 302 in each collection cycle is:

[0044] The adjustment index of the stirrer 302 in the i-th collection period is recorded as Y i ;

[0045] Where Y i is the adjustment index of the stirrer 302 in the i-th collection cycle; S i is the stirring speed of the stirrer 302 in the i-th collection cycle; is the absolute value of the difference between the slowness confidence of the i-th acquisition cycle and the mean of the slowness confidence of all standard cycles; is the absolute value of the difference between the too fast confidence level of the i-th acquisition cycle and the mean of the too fast confidence levels of all standard cycles;

[0046] Among them, the collection period in which the speed regulation confidence is less than the preset confidence threshold is the standard period.

[0047] Preferably, the method for correcting the stirring speed of the stirrer 302 in the current collection period to be stirred is:

[0048] Obtaining the initial stirring speed of the stirrer 302 in the current collection cycle to be stirred;

[0049] The adjustment index of the stirrer 302 in the previous collection cycle is summed with the initial stirring speed of the stirrer 302 in the current collection cycle to be stirred, so as to correct the stirring speed in the current collection cycle to be stirred.

[0050] The embodiments of the present application have at least the following beneficial effects:

[0051] (1) The simulation experiment is more in line with geological reality by comprehensively considering various factors affecting diagenesis, such as temperature, pressure, oxygen-free environment, the relationship between various fluids and diagenesis, the flow state of fluids, changes in rock porosity and permeability, changes in fluid ion concentration, hydrocarbon generation and expulsion, and clay mineral evolution. (2) A new type of diagenetic hydrocarbon generation reactor is used, which has better compaction and sealing effects, more precise temperature control, and a larger simulated temperature range. (3) Taking into account the particularity of shale diagenesis, the gas and liquid products are effectively separated, and the gaseous products can be collected and measured, avoiding environmental pollution, protecting the health of operators, and preventing the blockage of the discharge hole by fine shale debris. (4) The concentration of the fluid injected into the reactor remains stable and can be continuously injected into the diagenetic hydrocarbon generation reactor unit. (5) The fluid is preheated to avoid a temporary drop in the sample temperature. (6) The original pore structure of the shale is retained. (7) The sealing of the reactor is tested before the experiment, which improves the success rate of the experiment. (8) The dynamic changes of various parameters in the whole process of diagenetic simulation are detected, and the degree of automation is improved.

[0052] (9) This application addresses the problem that the existing diagenetic simulation device has no anti-precipitation measures, which affects the experimental results. This application places an agitator 302 in the anti-precipitation fluid container 301, and conducts an in-depth analysis of the liquid permeability, ion concentration and liquid level during stirring. By analyzing the degree of mixing of the liquid and the substance in the anti-precipitation fluid container 301, the slow confidence level is constructed to preliminarily evaluate whether the stirring speed is slow; then, by analyzing the characteristics of bubbles appearing in the liquid and violent fluctuations in the liquid level when the stirring speed is too fast, the too fast confidence level is constructed to evaluate whether the stirring speed is too fast; then, by constructing the speed adjustment confidence level, it is evaluated whether the current stirring speed needs to be adjusted; finally, by constructing the adjustment index, the appropriate stirring speed is set to ensure that the fluid concentration remains stable, thereby ensuring the stability of the experimental results. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0054] Figure 1 Schematic diagram of the structure of the high-temperature and high-pressure simulation device for clay mineral transformation in the shale diagenesis process provided in this application;

[0055] Figure 2 Schematic diagram of the diagenetic hydrocarbon generation reactor unit provided for this application;

[0056] Figure 3Schematic diagram of the high-temperature and high-pressure simulation device for clay mineral transformation in the shale diagenesis process provided in this application;

[0057] Figure 4 A workflow diagram for the high-temperature and high-pressure simulation method for clay mineral transformation in the shale diagenesis process provided in this application;

[0058] Figure 5 This is a flow chart of the process of adjusting and controlling the stirring speed of the stirrer 302 provided in this application.

[0059] Figure 1 : 100-diagenesis and hydrocarbon generation reactor unit, 200-temperature and pressure control unit, 300-fluid injection and liquid permeability detection unit, 400-gas-liquid separation, collection, metering and detection unit, 500-gas injection and permeability detection unit, 5001-introduction mechanism, 5002-extraction mechanism, 600-computer control unit.

[0060] Figure 2 :101-high-pressure sleeve, 102-sample chamber, 103-high-pressure autoclave body, 104 upper pressure threaded cap, 105-upper covering pressure plug three-way hole, 106-upper covering pressure plug, 107-upper pressure pad, 108-sealing component A, 109-upper filter, 110-lower filter, 111-sealing component B, 112-lower threaded barrel, 113-sealing component C, 114-lower support plug, 115-lower support plug three-way hole, 116-lower threaded pressure cap, 117-lower pressure pad, 118-semicircular vibration plate, 119-locking cap.

[0061] Figure 3:100-diagenetic hydrocarbon generation reactor unit, 201-heating system, 202-lower pressure cylinder, 203-upper pressure cylinder, 301-anti-sedimentation fluid container, 302-agitator, 303-photosensitive liquid level sensor, 304-fluid container cover, 305-fluid replenishing container, 306-fluid booster pump, 307-booster A, 308-preheating system, 309-pressure sensor A, 310-valve A, 311-valve K311, 401-valve B, 402-pressure sensor B, 403-automatic control valve, 404-back pressure device, 405-back pressure pump, 406-valve C, 407-gas-liquid separation tank, 408-cold trap A, 409-gas collection and metering Instrument, 410-valve D, 411-pressure relief pipe, 412-separation baffle A, 413-liquid receiving cup, 414-electronic balance, 415-ion concentration detector, 416-valve E, 417-gas-liquid separation funnel, 418-separation baffle B, 419-cold trap B, 420-negative pressure gas collector A, 501-valve F, 502-pressure sensor C, 503-valve G, 504-booster B, 505-gas booster pump, 506-pressure reducing valve, 507-valve H, 508-gas cylinder, 509-valve I, 510-pressure sensor D, 511-gas flow meter, 512-negative pressure gas collector B, 513-valve J, 514-vacuum system. DETAILED DESCRIPTION

[0062] To further illustrate the technical means and effects employed by this application to achieve the intended invention objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the high-temperature, high-pressure simulation device and method for clay mineral conversion during shale diagenesis proposed in this application. In the following description, references to different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0063] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0064] The specific scheme of the high-temperature and high-pressure simulation device and method for clay mineral conversion in the shale diagenesis process provided by this application is described in detail below with reference to the accompanying drawings.

[0065] As attached Figure 1 -Attached Figure 3As shown, the high-temperature and high-pressure simulation device for clay mineral conversion in the shale diagenesis process of the present application includes: a diagenesis and hydrocarbon generation reactor unit 100, a temperature and pressure control unit 200, a fluid injection and liquid permeability detection unit 300, a gas-liquid separation, collection, metering and detection unit 400, a gas injection and permeability detection unit 500, and a computer control unit 600, consisting of a total of 6 units.

[0066] The diagenetic hydrocarbon generation reactor unit 100 is inside the temperature and pressure control unit 200, the fluid injection and liquid permeability detection unit 300 is connected to one side of the upper overlying pressure plug three-way hole 105 of the diagenetic hydrocarbon generation reactor unit 100, the gas-liquid separation, collection, metering and detection unit 400 is connected to one side of the lower support plug three-way hole 115, and the gas injection and permeability detection unit 500 is divided into an introduction mechanism 5001 and an extraction mechanism 5002.

[0067] Among them, the introduction mechanism 5001 is connected to the other side of the three-way hole 105 of the upper covering pressure plug, and the lead-out mechanism 5002 is connected to the other side of the three-way hole 115 of the lower supporting plug. Each unit is connected to the computer control unit 600, and the valves, pumps and temperature control devices of each unit are controlled by the computer control unit 600.

[0068] The diagenetic hydrocarbon generation reactor unit 100 includes:

[0069] High-pressure sleeve 101, sample chamber 102, high-pressure autoclave body 103, upper pressure threaded cap 104, upper covering pressure plug three-way hole 105, upper covering pressure plug 106, upper pressure pad 107, sealing assembly A108, upper filter 109, lower filter 110, sealing assembly B111, lower threaded barrel 112, sealing assembly C113, lower support plug 114, lower support plug three-way hole 115, lower threaded pressure cap 116, lower pressure pad 117, semicircular vibration plate 118, locking cap 119.

[0070] The sample chamber 102 is a space enclosed by a high-pressure sleeve 101, an upper filter 109, and a lower filter 110. The high-pressure sleeve 101 is located within the autoclave body 103 and fits tightly therewith. Its bottom is flush with the bottom of the autoclave body 103, and its top is slightly shorter than the top of the autoclave body 103. The high-pressure sleeve 101 has threads on the inside of the top and outside of the bottom for connecting to the upper threaded pressure cap 104 and the lower threaded pressure cap 116. The autoclave body 103 has an overburden plug 106 on top for applying overburden pressure. The plug is composed of two cylindrical sections of different lengths, with an internal overburden plug three-way hole 105 with three through holes in three directions. One side of the coarse cylindrical plug fits the upper filter 109 and is built into the high-pressure sample cylinder 101. The thin cylindrical plug passes through the sealing assembly A108, the upper pressure pad 107, and the locking cap 119 from bottom to top. The locking cap 119 is threadedly connected to the overburden plug 106 to compact the upper pressure pad 107 and the sealing assembly A108. The overburden threaded cap 104 is composed of a hollow cylinder with different diameters at both ends. The outer side of the thin cylinder has threads that can be connected to the internal threads at the top of the autoclave body 103 to compact the high-pressure sleeve 101. The middle part is a coaxial hollow circle with the same diameter as the outer diameter of the upper pressure pad 107. The lower support plug 114 is composed of four parts: a thin cylinder, a middle cylinder, a flat-top cone and a thick cylinder. The lower support plug has a three-way hole 115 with through holes in three directions. There is an annular groove on its thin cylinder, and an annular sealing component C113 is arranged in the groove. The outer side of the lower part of the middle cylinder is threaded and can be connected to the lower threaded barrel 112. The thin diameter part of the lower support plug 114 passes through the trapezoidal sealing component B111, the lower pressure pad 117 and the lower threaded barrel 112 in sequence. The lower threaded pressure cap 116 is cylindrical and consists of two hollow circles of different diameters from top to bottom along its axis. There is a thread in the upper hollow circle, and its inner diameter is the same as the outer diameter of the high-pressure autoclave body 103. The lower hollow circle passes through the cylinder, and its inner diameter is the same as the outer diameter of the thin diameter part of the lower support plug 114. The lower threaded pressure cap 116 is used to support the high-pressure autoclave body 103, the high-pressure sleeve 101, the lower threaded barrel 112 and the lower support plug 114. The semicircular vibration plate 118 is composed of two semicircular vibration plates, which fit tightly against the autoclave body 103 and are used to knock on the vibration plate to generate micro-vibration, so that the water in the sample chamber can completely penetrate into the rock before heating and pressurizing. It must be disassembled before heating and pressurizing.

[0071] The temperature and pressure control unit 200 includes:

[0072] Heating system 201, lower pressure cylinder 202, upper pressure cylinder 203.

[0073] The heating system 201 completely encloses the sample chamber and controls the sample's incoming temperature. The lower pressure cylinder 202, connected to the lower support plug 114, applies pressure to and supports the sample. The upper pressure cylinder 203, connected to the upper overburden plug 106, applies overburden pressure to the sample. Both the upper and lower pressure cylinders 203 and 202 accurately measure plug displacement.

[0074] The fluid injection and liquid permeability detection unit 300 includes:

[0075] Anti-sedimentation fluid container 301, agitator 302, optical liquid level sensor 303, fluid container cover 304, fluid replenishing container 305, fluid booster pump 306, booster A307, preheating system 308, pressure sensor A309, valve A310, valve K311.

[0076] The anti-sedimentation fluid container 301 is made of transparent material and has an agitator 302 at its bottom for periodic stirring to prevent solute precipitation in the mineral solution within the container and maintain a stable solute concentration. A light-sensing level sensor 303 is fixed outside the anti-sedimentation fluid container 301, above the agitator 302, to monitor liquid level changes. The fluid container cover 304, located above the anti-sedimentation fluid container 301 for dust protection, has two circular holes for the fluid replenishment and discharge lines. Both lines are located above the agitator 302 but below the light-sensing level sensor 303. The fluid replenishment container 305 is connected to the anti-sedimentation fluid container 301 by pipelines, with a valve K311 located in between. The pressure booster A307 is connected to the anti-sedimentation fluid container 301 at one end and to the preheating system 308 at the other. Pressure is provided by a fluid booster pump 306 connected to the booster pump, which is used to increase the fluid pressure. The other side of the preheating system 308 is connected in sequence to a pressure sensor A309 and a valve A310. The other side of the valve A310 is connected to one lateral side of the three-way hole 105 of the overlying pressure plug.

[0077] The gas-liquid separation, collection, metering and detection unit 400 includes:

[0078] Valve B401, pressure sensor B402, automatic control valve 403, back pressure device 404, back pressure pump 405, valve C406, gas-liquid separation tank 407, cold trap A408, gas collection meter 409, valve D410, pressure relief pipe 411, separation baffle A412, liquid receiving cup 413, electronic balance 414, ion concentration detector 415, valve E416, gas-liquid separation funnel 417, separation baffle B418, cold trap B419, negative pressure gas collector A420.

[0079] One side of valve B401 is connected to the transverse through-hole of the lower support plug's three-way hole 115, and the other side is sequentially connected to pressure sensor B402, automatic control valve 403, and back-pressure device 404. Back-pressure device 404 is supplied with pressure by back-pressure pump 405. The other side of back-pressure device 404 has two branches. The first branch sequentially connects to valve C406, gas-liquid separation tank 407, and gas collection meter 409, which is located inside cold trap A408. The second branch sequentially connects to valve D410, pressure relief pipe 411, and gas-liquid separation funnel 417. The pressure relief pipe is a pipeline with a relatively large inner diameter, used to reduce the pressure of the fluid entering gas-liquid separation funnel 417. The gas-liquid separation funnel 417 is placed inside the cold trap B419. It has downward-angled separation baffles A412 and B418 inside. A small hole at its top connects to a negative pressure gas collector A420 via a pipeline. Its bottom is funnel-shaped, and the bottom and the small hole can be connected to the liquid receiving cup 413 via a pipeline. Separation baffle B418 is located above separation baffle A412. One side of separation baffle B418 fits tightly against the inner wall of gas-liquid separation funnel 417, while the other side extends diagonally downward, leaving a small gap with separation baffle A412 to allow liquid to flow downward. Separation baffle A412 fits tightly against the inner wall of gas-liquid separation funnel 417 on one side, while the other side extends diagonally downward, leaving a small gap with the inner wall of gas-liquid separation funnel 417 to allow liquid to flow downward. A valve E416 is located between gas-liquid separation funnel 417 and liquid receiving cup 413. The liquid receiving cup 413 is placed on an electronic balance 414 and is connected to an ion concentration detector 415 via a pipeline.

[0080] The gas injection and permeability detection unit 500 includes:

[0081] Valve F501, pressure sensor C502, valve G503, booster B504, gas booster pump 505, pressure reducing valve 506, valve H507, gas cylinder 508, valve I509, pressure sensor D510, gas flow meter 511, negative pressure gas collector B512, valve J513, vacuum system 514.

[0082] One side of the valve F501 is connected to the other side of the upper support plug's three-way hole 105. The other side of the valve F501 is connected to a pressure sensor C502, valve G503, a booster B504, a pressure reducing valve 506, a valve H507, and a gas cylinder 508. The gas booster pump 505 is connected to the booster B504 for boosting pressure. The other side of the lower support plug's three-way hole 115 is connected to two branches. The first branch is connected in sequence to a valve J513 and a vacuum system 514, while the second branch is connected in sequence to a valve I509, a pressure sensor D510, a gas flowmeter 511, and a negative pressure gas collector B512.

[0083] The computer control unit 600 is respectively connected to the diagenetic hydrocarbon generation reactor unit 100, the temperature and pressure control unit 200, the fluid injection and liquid permeability detection unit 300, the gas-liquid separation, collection, metering and detection unit 400, and the gas injection and permeability detection unit 500 to control the operation of each part.

[0084] See also Figure 4 , which shows a workflow diagram of a high-temperature and high-pressure simulation method for clay mineral transformation in the shale diagenesis process provided by the present application, the method comprising the following steps:

[0085] (1) Sample filling process: Place the rock sample (rock + clay / kerogen + clay minerals) into the sample chamber 109, and adjust the lower pressure cylinder 202 and the upper pressure cylinder 203 to compact the sample with a relatively small pressure.

[0086] (2) Working process of airtightness test: Close valves A310, D401, I509 and J513, and open valves F501, G503 and H507. The gas in cylinder 508 is decompressed by pressure reducing valve 506 and then adjusted to the appropriate pressure (P1) by the pressurization system consisting of booster B504 and gas booster pump 505. Close valves H507 and G503. If the pressure does not change for a long time (H1), the airtightness is qualified. Otherwise, the leak should be checked and the sample should be re-sealed and refilled.

[0087] (3) Gas permeability measurement process: Close valves A310, D401, and J513, and open valves F501, G503, H507, and I509. The gas in cylinder 508 is depressurized by pressure reducing valve 506 and then adjusted to an appropriate pressure by the pressurization system consisting of booster B504 and gas booster pump 505. After the gas flows through the sample, the gas flow rate is measured by gas flowmeter 511. Based on Darcy's law, the permeability can be calculated using the values ​​of pressure sensors C502 and D510 and the gas flow rate.

[0088] (4) Vacuuming process: Close valves A310, F501, D401, and I509. Open valve J513 and activate vacuum system 514 to evacuate and discharge the gas in sample chamber 102. Close valve J513 and vacuum system 514 in sequence to complete the vacuuming process.

[0089] (5) Liquid permeability measurement process and fluid ion concentration measurement process: Close valves F501, I509, C406, and J513, and open valves A310, D401, and E416. Turn on the agitator 302 to prevent solute precipitation in the fluid (it is also possible to have no solute at this time). The liquid in the anti-precipitation fluid container 301 is pressurized by the system composed of the booster A307 and the fluid booster pump 306 and preheated by the preheating system 308, and then injected into the sample chamber 102. The automatic control valve 403 is set to normally open, the back pressure device 404 is not set to pressure, and the cold trap 419 is working to cool. After the liquid is depressurized through the pressure relief pipe 411, it enters the gas-liquid separator funnel 417 and finally drips into the liquid receiving cup 413. The liquid flow rate is calculated using the reading and time of the electronic balance, and the values ​​of the pressure sensor A309 and the pressure sensor B401 are obtained. The permeability can be calculated using Darcy's law. The detection port of the ion concentration detector is connected to the bottom of the liquid receiving cup 413. The ion concentration of the mixed liquid in the liquid receiving cup is measured at a fixed period through program control, and the concentration of the fluid at different time points can be calculated based on the liquid volume and time in the liquid receiving cup at different time periods.

[0090] In this step of the process, the present application considers that if the stirring speed of the stirrer 302 is too slow, the sediment and the liquid cannot be fully mixed, which will affect the concentration stability of the drawn liquid; if the stirring speed is too fast, it will cause significant fluctuations on the liquid surface, which will make it impossible for the optical liquid level sensor 303 to accurately read the liquid level information, affecting the normal operation of the fluid replenishment mechanism; at the same time, if the stirring speed is too fast, it will also generate local high-speed eddy currents, thereby generating bubbles in the liquid, which will also affect the subsequent liquid concentration measurement. Therefore, it is necessary to adjust and control the stirring speed of the stirrer 302.

[0091] In this application, the process flow chart of regulating and controlling the stirring speed of the stirrer 302 is shown in the attached figure. Figure 5 As shown, specifically:

[0092] S1, obtain the permeability data, ion concentration data and liquid level data of the liquid in the anti-sedimentation fluid container 301 through the pressure sensor A309, the ion concentration detector 415 and the light-sensitive liquid level meter 303 respectively.

[0093] Since the stirrer 302 is turned on at a fixed time, the present application takes the data when the stirrer is turned on for the i-th time as an example for analysis. The stirring speed of the stirrer for the i-th time is obtained through the central control system of the present device.

[0094] Afterwards, the liquid being stirred in the anti-sedimentation fluid container 301 is pressurized and preheated. After the liquid undergoes pressure relief and gas-liquid separation operations and drips into the liquid receiving cup 413, the permeability data, ion concentration data, and liquid level data of the liquid in the anti-sedimentation fluid container 301 are obtained through a pressure sensor, an ion concentration detector, and a light-sensing liquid level meter.

[0095] Permeability and ion concentration data collection begins when the liquid drawn from the anti-sedimentation fluid container 301 begins dripping into the liquid receiving cup and ends when the drawn liquid has completely dripped into the liquid receiving cup 413. Liquid level data collection begins when the stirrer 302 is turned on and ends when the liquid level falls below the container's set lower limit.

[0096] Following the chronological order of data collection, construct the permeability, ion concentration, and liquid level sequences for the i-th withdrawal of liquid. To eliminate dimensionality effects between data, perform Z-score normalization on all data. The data collected at the start of the i-th agitator cycle is recorded as the data collected during the i-th acquisition cycle. In the same manner, collect data for a total of N acquisition cycles. In this example, N is set to 50, but the specific value can be set by the implementer.

[0097] S2, analyzing the distribution characteristics of the peak values ​​in the ion concentration data collected in each acquisition cycle, the slope estimation of the ion concentration data, and the chaotic distribution characteristics between the means of the ion concentration data divided into multiple subsequences, to determine the slow confidence of each acquisition cycle.

[0098] If the stirring speed of the stirrer 302 is appropriate, the liquid and the solute precipitate can be fully mixed during each stirring, and the ion concentration and permeability of the liquid drawn at different times during the stirring process should be relatively consistent. If the stirring speed is too slow, the solute precipitate will continue to gradually settle during the stirring process, resulting in inconsistent ion concentrations of the liquid at different liquid levels in the anti-sedimentation fluid container 301. Therefore, the ion concentration of the liquid drawn and dripped into the liquid receiving cup will vary significantly at different time periods.

[0099] The ion concentration sequence and permeability sequence in the i-th acquisition cycle are taken as an example for analysis.

[0100] A peak detection algorithm is used to obtain all peaks in the ion concentration sequence. The variance of all peaks is calculated, and the product of the peak variance and the number of peaks is recorded as the peak fluctuation difference of the ion concentration sequence. The greater the peak fluctuation difference, the greater the difference between the peaks, and the greater the number of peaks, indicating a greater possibility that the ion concentration sequence is not a stationary sequence.

[0101] The absolute value of the slope estimate of the ion concentration series is obtained using the Sen's slope estimation algorithm and recorded as the trend index of the concentration series. The larger the trend index, the greater the possibility of a significant trend change in the concentration series.

[0102] The PELT sequence segmentation algorithm is used to segment the ion concentration sequence into multiple subsequences. The mean of each subsequence is calculated, and the variance between the subsequence means is recorded as the phase index of the ion concentration sequence. A larger phase index indicates that the concentration differences between the subsequences in the ion concentration sequence at different time periods are greater.

[0103] The peak detection algorithm, Sen's slope estimation algorithm and PELT sequence segmentation algorithm are all well-known technologies and will not be described in detail.

[0104] The product of the peak fluctuation difference, trend index and phase index of the ion concentration series in the i-th acquisition cycle is recorded as the slow confidence of the i-th acquisition cycle.

[0105] It should be understood that the greater the slowness confidence, the greater the possibility that the ion concentration sequence has a strong stage-by-stage concentration change and large fluctuations, which means that when the agitator is turned on for the i-th time, its stirring speed is slow and the liquid and solute are not fully mixed.

[0106] S3, based on the distribution characteristics of the peak values ​​in the permeability data collected in each acquisition cycle, the average levels of the autocorrelation coefficients of the permeability data at different lag orders, and the data distribution characteristics after the second-order difference of the liquid level data collected in each acquisition cycle, determine the excessively fast confidence level for each acquisition cycle.

[0107] Furthermore, if the stirring speed is too fast, although the liquid and the solute will be fully mixed, more air will be introduced, generating bubbles, so that the drawn liquid contains air, and the flow rate of the drawn liquid changes, causing the liquid permeability calculated by Darcy's law to fluctuate; at the same time, too fast a stirring speed will also cause high-speed vortices to form on the liquid surface in the anti-sedimentation fluid container 301, thereby causing large fluctuations in the liquid level data detected by the optical liquid level sensor.

[0108] In this embodiment, the data distribution characteristics after the second-order difference of the liquid level data include: calculating the average level of all differential values ​​after the second-order difference of the liquid level data collected in each collection cycle; using the median after the second-order difference of the liquid level data collected in each collection cycle to divide all differential values ​​into a pre-sequence and a post-sequence; respectively calculating the sum of the slopes of the straight lines and the absolute values ​​of the differences after straight-line fitting of the pre-sequence and the post-sequence; and calculating the product of the summation result and the absolute values ​​of the differences; wherein the data distribution characteristics after the second-order difference of the liquid level data are determined by the sum of the average level of all differential values ​​and the result of the product.

[0109] In this embodiment, the method for determining the over-fast confidence level of each acquisition cycle is as follows: calculating the ratio of the autocorrelation coefficient under the different lag orders to the distribution characteristics of the peak value in the permeability data; and taking the ratio of the data distribution characteristics after the second-order difference of the liquid level data to the ratio as the over-fast confidence level of each acquisition cycle.

[0110] Specifically, as an implementation, the peak fluctuation differences of the permeability series are calculated using the same calculation steps as for the peak fluctuation differences of the concentration series to analyze the distribution characteristics of the peaks in the permeability data. Simultaneously, the mean of the absolute values ​​of the autocorrelation coefficients of the permeability series at lag order λ is calculated. In this embodiment, λ is an integer in the range [5, 20] and is denoted as the internal consistency index of the permeability series.

[0111] The ratio of the internal consistency index of the permeability series to the peak fluctuation difference is recorded as the stability coefficient of the permeability series. A larger stability coefficient reflects a more stable permeability of the extracted liquid and a greater likelihood of an appropriate stirring speed during the i-th collection cycle.

[0112] Furthermore, since the liquid level in the anti-sedimentation fluid container 301 is continuously decreasing when being drawn out, if the stirring speed is appropriate or slow, the liquid level should decrease steadily; however, if the stirring speed is too fast, the fluctuation of the liquid level during the decrease will be greater, and the fluctuation of the liquid level will be more violent as the liquid level gradually decreases.

[0113] Obtain the second-order difference sequence of the liquid level sequence, and record the mean of the second-order difference sequence as the liquid level sequence's downward fluctuation index. A larger downward fluctuation index indicates a more inconsistent decrease in the liquid level within the anti-sedimentation fluid container 301, and a greater likelihood that excessive stirring speed is causing violent fluctuations in the liquid level.

[0114] Furthermore, the second-order difference sequence of the liquid level sequence is split into two subsequences using the median of its second-order difference sequence, each denoted as the pre-sequence and the post-sequence. Linear fits are performed on the pre-sequence and the post-sequence to obtain two fitted lines. The sum and difference of the absolute values ​​of the slopes of the two fitted lines are calculated, and the product of the sum and the difference is recorded as the gradual fluctuation index of the liquid level sequence. A larger gradual fluctuation index indicates more dramatic fluctuations in the liquid level as the liquid is withdrawn.

[0115] The sum of the downward fluctuation index and the gradual fluctuation index of the liquid level sequence is recorded as the intensity coefficient of the liquid level sequence. A larger intensity coefficient reflects a greater amplitude and frequency of liquid level fluctuations. In other words, during the liquid withdrawal process, the liquid level in the anti-sedimentation fluid container 301 decreases unsteadily and fluctuates dramatically, which increases the likelihood of excessive stirring speed.

[0116] The ratio of the dramatic coefficient of the liquid level sequence to the stability index of the permeability sequence is used as the speed adjustment confidence of the corresponding acquisition period to characterize the possibility of dramatic fluctuations in the permeability and liquid level drop of the liquid in the anti-sedimentation fluid container 301.

[0117] It should be understood that if the confidence level is greater, the intensity coefficient is greater and the stability index is smaller; the greater the intensity coefficient, the greater the fluctuation of the liquid level and the greater the possibility of excessive stirring speed; and the smaller the stability index, the more unstable the change in permeability, the greater the possibility of bubbles appearing in the liquid and the greater the possibility of excessive stirring speed.

[0118] S4, taking the difference between the slow confidence and the too fast confidence as the speed adjustment confidence of the corresponding acquisition period.

[0119] Specifically, as an implementation method, the confidence D is adjusted at the speed of the i-th acquisition cycle. i For example, let D i =norm(|A i -C i |); where D i A is the confidence level for the speed adjustment of the i-th acquisition cycle; i is the slow confidence of the i-th acquisition cycle; C i is the over-fast confidence of the i-th acquisition cycle; the norm() function is the normalization function.

[0120] If the speed adjustment confidence is smaller, it indicates that the concentration and permeability of the drawn liquid, as well as the drop in the liquid level in the anti-sedimentation fluid container 301, are all stable, indicating a greater likelihood that the stirring speed is appropriate, and no speed adjustment is required. If the speed adjustment confidence is larger, it indicates a greater likelihood that the concentration of the drawn liquid is fluctuating significantly, or that the permeability and liquid level are fluctuating dramatically, indicating a greater likelihood that the stirring speed is too slow or too fast.

[0121] S5, using the comparison result of the speed adjustment confidence and the preset confidence threshold, as well as the slow confidence, the too fast confidence and the stirring speed of the stirrer 302, determine the adjustment index of the stirrer 302 in each collection cycle; and correct the stirring speed of the stirrer 302 in the current collection cycle to be stirred.

[0122] In the same manner as step S4, the speed adjustment confidence of each acquisition cycle is obtained and compared with the preset confidence threshold δ; wherein the preset confidence threshold δ∈(0,1] is 0.5 in this embodiment and can be set by the implementer.

[0123] If the speed adjustment confidence is less than δ, it means that the stirring speed of the stirrer is relatively appropriate. At this time, there is no need to adjust the stirring speed. All collection cycles with speed adjustment confidence less than δ are recorded as standard cycles. Otherwise, the collection cycles greater than or equal to δ are recorded as non-standard cycles.

[0124] In order to further analyze the adjustment index of the stirrer 302 in each collection cycle, the adjustment index Y of the stirrer 302 in the i-th collection cycle is i For example, when it is a standard cycle, the adjustment index is 0, and when it is a non-standard cycle, the adjustment index is determined based on the slow confidence level, the too-fast confidence level, and the stirring speed of the stirrer 302 .

[0125] Among them, Where Y i is the adjustment index of the stirrer 302 in the i-th collection cycle; S i is the stirring speed of the stirrer 302 in the i-th collection cycle; is the absolute value of the difference between the slowness confidence of the i-th acquisition cycle and the mean of the slowness confidence of all standard cycles; is the absolute value of the difference between the too-fast confidence level of the i-th acquisition cycle and the mean of the too-fast confidence levels of all standard cycles.

[0126] If the speed adjustment confidence is greater than or equal to δ, it means that the stirring speed is too fast or too slow. At this time, the data characteristics caused by the stirring speed being too fast or too slow are analyzed to evaluate whether the stirring speed is too fast or too slow, and the stirring speed is adjusted according to the evaluation results.

[0127] The initial stirring speed of the stirrer 302 in the current collection cycle to be stirred is obtained, and the adjustment index of the stirrer 302 in the previous collection cycle is summed with the initial stirring speed of the stirrer 302 in the current collection cycle to be stirred to optimize the stirring speed in the current collection cycle to be stirred, thereby maintaining sufficient mixing of the liquid and the solute and ensuring the stability of the liquid concentration.

[0128] (6) Working process of fluid replenishment and injection: Open the optical liquid level sensor 303. When the liquid in the anti-sedimentation fluid container 301 is lower than the lower limit position of the optical liquid level sensor 303, the valve K311 automatically opens, and the liquid in the fluid replenishment container 305 flows into the anti-sedimentation fluid container 301. When the liquid is higher than the upper limit position of the optical liquid level sensor 303, the valve K311 automatically closes, thereby realizing the replenishment and injection of the fluid.

[0129] (7) Porosity change process: The change in sample volume is determined based on the changes in the positions of the upper pressure plug 106 and the lower support plug 114 recorded by the lower pressure cylinder 202 and the upper pressure cylinder 203 measured multiple times, thereby calculating the change in porosity.

[0130] (8) Simulation workflow of clay minerals in the shale diagenesis process under multiple geological factors under high temperature and high pressure: After loading the sample according to method (1), close valves F501, I509 and J513, and open valves A310 and B401. The fluid state can be changed by adjusting valve A310. The pressure of the sample can be adjusted by program-controlled positions of the lower pressure cylinder 202 and the upper pressure cylinder 203. The temperature of the sample can be controlled by the heating system 201. The mineral fluid with a known concentration is pressurized by the pressurization system composed of the fluid booster pump 306 and the booster A307, and then enters the preheating system 308 to be preheated to the same temperature as the sample, and then injected into the sample chamber 102. The pressure P2 of the back pressure system is formed by setting the back pressure device 404 and the back pressure pump 405. When the fluid pressure ≥ P2, the automatic control valve 403 is opened. When the fluid pressure < P2, the automatic control valve 403 is closed, thereby realizing the control of the hydrocarbon discharge mode. After the back pressure system, two process branches can be selected. The first branch requires closing valve D410 and opening valve C406. At this time, the generated oil, gas and mineral fluid enter the gas-liquid separation tank 407. After separation by the cold trap A408, the oil and mineral fluid are collected by the gas-liquid separation tank 407, and the gas is collected and measured by the gas collection meter 409. The second branch requires closing valve C406 and opening valve D410. At this time, the generated oil, gas and mineral fluid enter the pressure relief pipe 411 for pressure relief. After that, the gas-liquid mixture enters the gas-liquid separation funnel 417. The gas-liquid separation funnel 417 is in the cold trap B. The liquid entering the funnel is guided by the separation baffle A and the separation baffle B along the pipeline below the funnel into the liquid receiving cup 413. The liquid weight is recorded by the electronic balance 414, the liquid ion concentration is measured by the ion concentration detector 415, and the gas is collected by the negative pressure gas collector A420. During the experiment, the permeability can be tested and the mineral fluid can be replenished at any time according to steps (3), (5), (6), and (7). This enables the simulation of various factors affecting diagenesis, such as temperature, pressure, anaerobic environment, the relationship between various fluids and diagenesis, fluid flow state, changes in rock porosity and permeability, changes in fluid ion concentration, hydrocarbon generation and expulsion, and clay mineral evolution.

[0131] The various embodiments in this application are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0132] It should be noted that, unless otherwise specified and limited, terms such as "include", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the phrase "including a ..." defines an element, does not exclude the presence of other identical elements in the article or device including the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items.

[0133] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not invented herein.

[0134] It will be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A high-temperature and high-pressure simulation device for clay mineral transformation during shale diagenesis, characterized in that: The device comprises: a diagenetic hydrocarbon generation reactor unit (100), a temperature and pressure control unit (200), a fluid injection and liquid permeability detection unit (300), a gas-liquid separation, collection, metering and detection unit (400), a gas injection and permeability detection unit (500) and a computer control unit (600); The diagenetic hydrocarbon generation reactor unit (100) is located inside the temperature and pressure control unit (200); the fluid injection and liquid permeability detection unit (300) is connected to one side of the upper pressure plug three-way hole (105) of the diagenetic hydrocarbon generation reactor unit (100); the gas-liquid separation, collection, metering and detection unit (400) is connected to one side of the lower support plug three-way hole (115); and the gas injection and permeability detection unit (500) is divided into an introduction mechanism (5001) and an extraction mechanism (5002); The introduction mechanism (5001) is connected to the other side of the three-way hole (105) of the upper pressure plug, and the lead-out mechanism (5002) is connected to the other side of the three-way hole (115) of the lower support plug. Each unit is connected to the computer control unit (600).

2. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 1, characterized in that: The diagenetic hydrocarbon generation reactor unit (100) comprises: a high-pressure sleeve (101), a sample chamber (102), a high-pressure reactor body (103), an upper pressure threaded cap (104), an upper pressure plug three-way hole (105), an upper pressure plug (106), an upper pressure pad (107), a sealing assembly (A108), an upper filter (109), a lower filter (110), a sealing assembly (B111), a lower threaded barrel (112), a sealing assembly (C103), a lower support plug (114), a lower support plug three-way hole (115), a lower threaded pressure cap (116), a lower pressure pad (117), a semicircular vibration plate (118), and a locking cap (119).

3. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 2, characterized in that: The sample chamber (102) is a space formed by the high-pressure sleeve (101), the upper filter (109) and the lower filter (110).

4. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 2, characterized in that: The upper part of the high-pressure autoclave body (103) is provided with an overlying pressure plug (103) for applying overlying pressure. The plug is composed of two cylinders of different lengths, and contains a three-way overlying pressure plug (105) with through holes in three directions. One side of the coarse cylindrical body of the plug is in contact with the upper filter plate (109) and is built into the high-pressure sample cylinder (101). One side of the thin cylindrical body of the plug passes through the sealing component (A108), the upper pressure pad (107), and the locking cap (119) from bottom to top in sequence, wherein the locking cap (119) is connected to the overlying pressure plug (106) by a thread, and is used to compact the upper pressure pad (107) and the sealing component (A108).

5. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 2, characterized in that: The lower support plug (114) is composed of a thin cylinder, a middle cylinder, a flat-top cone and a thick cylinder (4). The lower support plug has a three-way hole (115) with three through holes in three directions. The thin cylinder has an annular groove, and the groove has an annular sealing component (C113). The outer side of the lower part of the middle cylinder has a thread and can be connected to the lower threaded barrel (112). The thin diameter part of the lower support plug (114) passes through the trapezoidal sealing component (B111), the lower pressure pad (117) and the lower threaded barrel (112). The threaded cylinder (112) and the lower threaded pressing cap (116) are cylindrical and are composed of two hollow circles with different diameters from top to bottom along their axis. The upper hollow circle has a thread inside, and its inner diameter is the same as the outer diameter of the autoclave body (103). The lower hollow circle passes through the cylinder, and its inner diameter is the same as the outer diameter of the thin diameter part of the lower support plug (114). The lower threaded pressing cap (116) is used to support the autoclave body (103), the high-pressure sleeve (101), the lower threaded cylinder (112) and the lower support plug (114).

6. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 2, characterized in that: The semicircular vibration plate (118) is composed of two semicircular vibration plates, which are tightly fitted to the autoclave body (103) and are used to knock the vibration plate to generate micro-vibration, so that the water in the sample chamber can be completely infiltrated into the rock before heating and pressurizing. It must be disassembled before heating and pressurizing.

7. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 1, characterized in that: The temperature and pressure control unit (200) comprises: a heating system (201), a lower pressure oil cylinder (202), and an upper pressure oil cylinder (203); the upper pressure oil cylinder (203) and the lower pressure oil cylinder (202) both have a plug displacement measurement function.

8. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 1, characterized in that: The fluid injection and liquid permeability detection unit (300) comprises: an anti-sedimentation fluid container (301), an agitator (302), a light-sensitive liquid level indicator (303), a fluid container cover (304), a fluid replenishing container (305), a fluid booster pump (306), a booster (A307), a preheating system (308), a pressure sensor (A309), a valve (A310), and a valve (K311).

9. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 8, characterized in that: The anti-precipitation fluid container (301) is made of a transparent material and has a stirrer (302) at its bottom for periodic stirring to prevent solute precipitation in the mineral solution in the container and maintain a stable solute concentration.

10. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 8, characterized in that: The optical liquid level sensor (303) is fixed at a position higher than the stirrer (302) outside the anti-sedimentation fluid container (301) and is used to monitor the change of the liquid level. When the liquid in the anti-sedimentation fluid container (301) is lower than the lower limit position of the optical liquid level sensor (303), the valve (K311) automatically opens, and the liquid in the fluid replenishment container (305) flows into the anti-sedimentation fluid container (301). When the liquid is higher than the upper limit position of the optical liquid level sensor (303), the valve (K311) automatically closes, thereby realizing the replenishment injection of the fluid.

11. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 8, characterized in that: The fluid container cover (304) is located above the anti-sedimentation fluid container (301) and is used for dust prevention. It has two circular holes through which the fluid replenishment pipeline and the lead-out pipeline pass. The positions of the two pipelines are higher than the agitator (302) but lower than the light-sensing liquid level meter (303).

12. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 1, characterized in that: The gas-liquid separation, collection, metering and detection unit (400) includes: a valve (B401), a pressure sensor (B402), an automatic control valve (403), a back pressure device (404), a back pressure pump (405), a valve (C406), a gas-liquid separation tank (407), a cold trap (A408), a gas collection meter (409), a valve (D410), a pressure relief pipe (411), a separation baffle (A412), a liquid receiving cup (413), an electronic balance (414), an ion concentration detector (415), a valve (E416), a gas-liquid separation funnel (417), a separation baffle (B418), a cold trap (B419), and a negative pressure gas collector (A420).

13. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 12, characterized in that: One side of the back pressure device (404) is connected to the automatic control valve, and the other side has two branches. The first branch is connected to the valve (C406), the gas-liquid separation tank (407), and the gas collection meter (409) in sequence, wherein the gas collection meter (409) is inside the cold trap (A408); the second branch is connected to the valve (D410), the pressure relief pipe (411) and the gas-liquid separation funnel (417) in sequence, wherein the pressure relief pipe is a pipeline with a relatively thick inner diameter and is used to reduce the pressure of the fluid entering the gas-liquid separation funnel (417).

14. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 12, characterized in that: The gas-liquid separation funnel (417) is placed inside the cold trap (B419). The separatory funnel has downwardly inclined separation baffles (A412) and separation baffles (B418). A small hole is provided on the top of the separatory funnel and is connected to the negative pressure gas collector (A420) through a pipeline. The bottom of the separatory funnel is in the shape of a funnel, and the bottom and the small hole can be extended to the liquid receiving cup (413) through a pipeline. Among them, the separation baffle (B418) is above the separation baffle (A412), one side of which is tightly fitted with the inner wall of the gas-liquid separation funnel (417), and the other side extends obliquely downward and has a small gap with the separation baffle (A412), allowing liquid to flow downward; one side of the separation baffle (A412) is tightly fitted with the inner wall of the gas-liquid separation funnel (417), and the other side extends obliquely downward and retains a small gap with the inner wall of the gas-liquid separation funnel (417), allowing liquid to flow downward; a valve (E416) is provided between the gas-liquid separation funnel (417) and the liquid receiving cup (413).

15. The high-temperature and high-pressure simulation device for clay mineral transformation in shale diagenesis according to claim 1, characterized in that: The gas injection and permeability detection unit (500) comprises: a valve (F501), a pressure sensor (C502), a valve (G503), a booster (B504), a gas booster pump (505), a pressure reducing valve (506), a valve (H507), a gas cylinder (508), a valve (I509), a pressure sensor (D510), a gas flow meter (511), a negative pressure gas collector (B512), a valve (J513), and a vacuum system (514); and can be used for tightness testing, anaerobic environment simulation, and gas permeability measurement.

16. A high-temperature and high-pressure simulation method for clay mineral transformation in shale diagenesis, implemented on the basis of the apparatus according to any one of claims 1 to 15, characterized in that: When measuring the liquid permeability and fluid ion concentration of a rock sample, the stirring speed of the stirrer (302) is adjusted and controlled based on the changes in the permeability data, ion concentration data, and liquid level data of the liquid in the anti-sedimentation fluid container (301) during each collection cycle. The following steps are involved: S1, obtaining permeability data, ion concentration data and liquid level data of the liquid in the anti-sedimentation fluid container (301) through the pressure sensor (A309), the ion concentration detector (415) and the light-sensitive liquid level meter (303); S2, analyzing the distribution characteristics of the peak values ​​in the ion concentration data collected in each acquisition cycle, the slope estimation of the ion concentration data, and the chaotic distribution characteristics between the means of the ion concentration data divided into multiple subsequences, and determining the slow confidence of each acquisition cycle; S3, determining the over-rapid confidence level for each acquisition cycle based on the distribution characteristics of the peak values ​​in the permeability data collected in each acquisition cycle, the average levels of the autocorrelation coefficients of the permeability data at different lag orders, and the data distribution characteristics after the second-order difference of the liquid level data collected in each acquisition cycle; S4, taking the difference between the slow confidence and the too fast confidence as the speed adjustment confidence of the corresponding acquisition cycle; S5, using the comparison result of the speed adjustment confidence and the preset confidence threshold, as well as the slow confidence, the too fast confidence and the stirring speed of the stirrer (302), to determine the adjustment index of the stirrer (302) in each collection cycle; and correct the stirring speed of the stirrer (302) in the current collection cycle to be stirred.

17. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 16, characterized in that: The rock sample includes rock, clay or kerogen, and clay minerals.

18. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 16, characterized in that: The slow confidence of each acquisition cycle is determined by the product of the distribution characteristics of the peak value of the concentration data in the corresponding acquisition cycle, the slope estimate, and the chaotic distribution characteristics between the means.

19. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 18, characterized in that: In step S2, the peak distribution characteristics are further determined as the product of the peak variance and the number of peaks in the concentration data.

20. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 16, characterized in that: The data distribution characteristics after the second-order difference of the liquid level data include: Calculate the average level of all differential values ​​after the second-order difference of the liquid level data collected in each collection cycle; Using the median of the second-order difference of the liquid level data collected in each collection cycle, all difference values ​​are divided into the pre-sequence and post-sequence; Calculate the sum of the slopes and the absolute value of the differences of the linear fitting results of the pre-sequence and post-sequence respectively; Calculate the product of the summation result and the absolute value of the difference; The data distribution characteristics after the second-order difference of the liquid level data are determined by the average level of all the difference values ​​and the sum of the product results.

21. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 20, characterized in that: In step S3, the method for determining the over-speed confidence level of each acquisition cycle is as follows: Calculating the ratio of the autocorrelation coefficient at different lag orders to the distribution characteristics of the peak value in the permeability data; The ratio of the data distribution characteristics after the second-order difference of the liquid level data and the ratio is used as the over-speed confidence of each acquisition cycle.

22. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 16, characterized in that: The method for determining the adjustment index of the stirrer (302) in each collection cycle is: The adjustment index of the stirrer (302) in the i-th collection cycle is recorded as Y i ; Where Y i S is the adjustment index of the stirrer (302) in the i-th collection cycle; i is the stirring speed of the stirrer (302) in the i-th collection cycle; is the absolute value of the difference between the slowness confidence of the i-th acquisition cycle and the mean of the slowness confidence of all standard cycles; is the absolute value of the difference between the too fast confidence level of the i-th acquisition cycle and the mean of the too fast confidence levels of all standard cycles; Among them, the collection period in which the speed regulation confidence is less than the preset confidence threshold is the standard period.

23. The high temperature and high pressure simulation method for clay mineral transformation in shale diagenesis according to claim 16, characterized in that: The method for correcting the stirring speed of the stirrer (302) in the current collection period to be stirred is: Obtaining the initial stirring speed of the stirrer (302) in the current collection cycle to be stirred; The adjustment index of the stirrer (302) in the previous collection cycle is summed with the initial stirring speed of the stirrer (302) in the current collection cycle to be stirred, so as to correct the stirring speed in the current collection cycle to be stirred.

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