Optimization system for steam huff and puff of shale oil with assistance of carbon dioxide and air

Abstract

The invention provides an optimization system for steam huff and puff of shale oil assisted by carbon dioxide and air, and relates to the field of shale oil reservoir exploitation. In the system, a constant-speed constant-pressure pump is connected with a carbon dioxide storage tank to liquefy gaseous carbon dioxide; the constant-speed constant-pressure pump is also respectively connected with an air storage tank, a shale oil intermediate container, a water intermediate container, a proppant intermediate container and a sealed distilled water container; the steam generator is connected with the sealed distilled water container and vaporizes distilled water in the sealed distilled water container; the triaxial experimental equipment is respectively connected with the constant-speed constant-pressure pump and the steam generator and is used for carrying out huff-puff reaction; the thermogravimetric analyzer is respectively connected with the carbon dioxide storage tank, the air storage tank and the steam generator to carry out a gas injection ratio optimization experiment. According to the invention, the efficiency of carbon dioxide and air-assisted steam huff and puff is optimized.

Description

Technical Field

[0001] The present application relates to the field of shale oil reservoir exploitation, and in particular to an optimization system for carbon dioxide and air-assisted steam throughput of shale oil. Background Art

[0002] Steam huff and puff technology is based on single-well operation and is easy to implement on site. It is a conventional means of exploiting low-maturity shale reservoirs. However, as the exploitation process deepens, steam huff and puff faces problems such as high energy consumption, high cost, low efficiency, increased process complexity, and serious environmental pollution. In the middle and late stages of steam huff and puff, other replacement technologies need to be adopted to solve these problems. Generally, gas-assisted steam huff and puff is added, such as carbon dioxide and air.

[0003] Steam stimulation is a conventional method for exploiting low-maturity shale reservoirs. In the middle and late stages of steam stimulation, other replacement technologies need to be adopted to solve problems such as high energy consumption, high cost, low efficiency, increased process complexity, and serious environmental pollution as the exploitation process deepens.

[0004] In the prior art, steam huff and puff is mainly assisted by adding gas, and the gas is generally carbon dioxide and air. Carbon dioxide and air assisted steam huff and puff have achieved good results in the field, and a large number of experimental studies have shown that they further improve the recovery rate.

[0005] The recovery rate of CO2 and air-assisted steam huff and puff is affected by temperature, injection volume, and different oxidation reaction stages. The existing experimental device cannot simultaneously consider the impact of multiple factors on the recovery rate, which not only reduces energy utilization, but also affects the efficiency of CO2 and air-assisted steam huff and puff. Summary of the invention

[0006] The present application provides an optimization system for carbon dioxide and air-assisted steam throughput of shale oil, which is used to solve the problem that the existing experimental equipment cannot simultaneously consider the impact of multiple factors on the recovery rate, which not only reduces the energy utilization rate, but also affects the efficiency of carbon dioxide and air-assisted steam throughput.

[0007] In a first aspect, the present application provides an optimization system for carbon dioxide and air-assisted steam throughput of shale oil, the system comprising: a carbon dioxide storage tank, an air storage tank, a sealed distilled water container, a shale oil intermediate container, a water intermediate container, a proppant intermediate container, a constant speed and pressure pump, a steam generator, a thermogravimetric analyzer, and a triaxial experimental device;

[0008] The constant speed and constant pressure pump is connected to the carbon dioxide storage tank, and the constant speed and constant pressure pump is used to liquefy the gaseous carbon dioxide in the carbon dioxide storage tank;

[0009] The constant speed and constant pressure pump is also connected to the air storage tank, the shale oil intermediate container, the water intermediate container and the proppant intermediate container respectively, and the sealed distilled water container is connected to the constant speed and constant pressure pump;

[0010] The steam generator is connected to the sealed distilled water container, and the steam generator is used to vaporize the distilled water in the sealed distilled water container;

[0011] The triaxial experimental equipment is connected to the constant speed and constant pressure pump and the steam generator respectively, and the triaxial experimental equipment is used to perform a throughput reaction;

[0012] The thermogravimetric analyzer is connected to the carbon dioxide storage tank, the air storage tank and the steam generator respectively, and is used to carry out a gas injection ratio optimization experiment.

[0013] In one possible design, the triaxial test apparatus is also used to perform a fracturing reaction on the rock sample in the triaxial test apparatus by injecting liquid carbon dioxide through a constant speed and constant pressure pump;

[0014] The system further comprises: a twelfth stop valve, an eleventh stop valve, a fifth stop valve, a sixth stop valve, a seventh stop valve and a waste liquid collection device;

[0015] The first port of the twelfth stop valve is connected to the carbon dioxide storage tank;

[0016] The first port of the eleventh stop valve is connected to the second port of the twelfth stop valve, and the first port of the constant speed and constant pressure pump is connected to the second port of the eleventh stop valve;

[0017] The first port of the fifth stop valve is connected to the second port of the constant speed and constant pressure pump, the first port of the sixth stop valve is connected to the second port of the fifth stop valve, and the first port of the triaxial experimental device is connected to the second port of the sixth stop valve;

[0018] The first port of the seventh stop valve is connected to the second port of the triaxial experimental equipment, and the waste liquid collection device is connected to the second port of the seventh stop valve. The waste liquid collection device is used to collect waste liquid generated by the fracturing reaction in the triaxial experimental equipment.

[0019] In one possible design, the triaxial experimental apparatus is also used to form a complex fracture network in the rock sample by injecting proppant at a constant rate and pressure during the fracturing reaction;

[0020] The system further comprises: a first stop valve, a second stop valve, a third stop valve, a fourth stop valve and a thirteenth stop valve;

[0021] The first port of the thirteenth stop valve is connected to the proppant intermediate container, the first port of the fourth stop valve is connected to the second port of the thirteenth stop valve, the second port of the constant speed and constant pressure pump is connected to the second port of the fourth stop valve, the first port of the first stop valve is connected to the first port of the constant speed and constant pressure pump, the first port of the sealed distilled water container is connected to the second port of the first stop valve, the first port of the second stop valve is connected to the second port of the sealed distilled water container, the first port of the steam generator is connected to the second port of the second stop valve, the first port of the third stop valve is connected to the second port of the steam generator, and the first port of the triaxial test device is connected to the second port of the third stop valve;

[0022] The waste liquid collection device is used to collect waste liquid generated when a complex fracture network is formed in the rock sample.

[0023] In one possible design, the triaxial test apparatus is also used to saturate the rock sample in the triaxial test apparatus with water and shale oil injected by a constant speed and pressure pump;

[0024] The system further comprises: a ninth stop valve, a tenth stop valve, a fourteenth stop valve and a fifteenth stop valve;

[0025] The first port of the fourteenth stop valve is connected to the water intermediate container; the first port of the fifteenth stop valve is connected to the shale oil intermediate container; the first port of the fourth stop valve is connected to the second port of the fourteenth stop valve and the second port of the fifteenth stop valve respectively;

[0026] The first port of the tenth stop valve is connected to the first port of the eleventh stop valve, the first port of the ninth stop valve is connected to the second port of the tenth stop valve; the first port of the triaxial experimental device is connected to the second port of the ninth stop valve;

[0027] The waste liquid collection device is used to collect the waste liquid generated by the saturated reaction in the triaxial experimental equipment.

[0028] In one possible design, the system further includes: a sixteenth stop valve, a first metering pump, and a second metering pump;

[0029] A first port of the first metering pump is connected to a second port of the steam generator, and a first port of the third stop valve is connected to the second port of the first metering pump;

[0030] The first port of the sixteenth stop valve is connected to the air storage tank, the first port of the eleventh stop valve is connected to the second port of the sixteenth stop valve, the first port of the second metering pump is connected to the second port of the eleventh stop valve; the first port of the constant speed and constant pressure pump is connected to the second port of the second metering pump.

[0031] In a possible design, when the first stop valve, the third stop valve, the fourth stop valve, the sixth stop valve and the seventh stop valve are closed, the triaxial test equipment is also used to perform a soaking reaction on the rock sample in the triaxial test equipment through the steam injected by the first metering pump and the carbon dioxide and air injected by the second metering pump.

[0032] In one possible design, the system further includes: an eighth stop valve, a separation device, and a seventeenth stop valve;

[0033] The first port of the eighth stop valve is connected to the first port of the triaxial experimental device, and the first port of the separation device is connected to the second port of the eighth stop valve;

[0034] After the simmering reaction is completed, the separation device is used to separate the products generated by the simmering reaction in the triaxial experimental device;

[0035] The first port of the seventeenth stop valve is connected to the first port of the thermogravimetric analyzer, and the second port of the separation device is connected to the second port of the seventeenth stop valve.

[0036] In one possible design, the system further includes: a third metering pump;

[0037] The second port of the ninth stop valve is connected to the second port of the third stop valve, and the second port of the thermogravimetric analyzer is connected to the first port of the ninth stop valve;

[0038] The first port of the third metering pump is connected to the second port of the tenth stop valve, and the second port of the thermogravimetric analyzer is connected to the second port of the third metering pump;

[0039] The thermogravimetric analyzer is also used to perform a gas injection ratio optimization experiment on a shale oil sample in the thermogravimetric analyzer by injecting a first volume of steam through a first metering pump and a second volume of air and a third volume of carbon dioxide through a third metering pump; wherein the ratio of the first volume to the second volume to the third volume is a preset ratio.

[0040] In a possible design, the triaxial test apparatus further includes: a confining pressure chamber, an axial pressure chamber, a heating device, a silicone sleeve, and a hydraulic loading unit;

[0041] The hydraulic loading unit is used to apply confining pressure to the confining pressure chamber and axial pressure to the axial pressure chamber connection to simulate formation conditions;

[0042] The heating device is used to heat the rock sample.

[0043] In one possible design, the system further includes: a pressure sensor, a temperature sensor, and a computer;

[0044] The computer is used to control the hydraulic loading unit to apply confining pressure and axial pressure;

[0045] The temperature sensor is used to monitor the temperature of the rock sample, and the pressure sensor is used to monitor the pressure of the confining pressure and axial pressure.

[0046] The present application provides a carbon dioxide and air-assisted steam intake and exhaust optimization system for shale oil, the system comprising: a carbon dioxide storage tank, an air storage tank, a sealed distilled water container, a shale oil intermediate container, a water intermediate container, a proppant intermediate container, a constant speed and pressure pump, a steam generator, a thermogravimetric analyzer and a triaxial experimental device; the constant speed and pressure pump is connected to the carbon dioxide storage tank, and the constant speed and pressure pump is used to liquefy the gaseous carbon dioxide in the carbon dioxide storage tank; the constant speed and pressure pump is also connected to the air storage tank, the shale oil intermediate container, the water intermediate container and the proppant intermediate container respectively, and the sealed distilled water container is connected to the constant speed and pressure pump; the steam generator is connected to the sealed distilled water container, and the steam generator is used to vaporize the distilled water in the sealed distilled water container; the triaxial experimental device is respectively connected to the constant speed and pressure pump and the steam generator, and the triaxial experimental device is used to perform intake and exhaust reactions; the thermogravimetric analyzer is respectively connected to the carbon dioxide storage tank, the air storage tank and the steam generator, and the thermogravimetric analyzer is used to perform a gas injection ratio optimization experiment. This application uses triaxial experimental equipment and thermogravimetric analyzer to study the effect of the injection ratio of carbon dioxide, air, and steam on the shale oil recovery rate during shale oil extraction by first fracturing and then repeating the huff-and-puff experiment. The quality changes of the reactants are monitored in real time, and the injection ratio of carbon dioxide, air, and steam is dynamically adjusted to find the gas injection ratio that can greatly improve the shale oil recovery rate, shale oil extraction efficiency, and energy utilization, thereby optimizing the efficiency of carbon dioxide and air-assisted steam huff-and-puff. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A schematic diagram of a carbon dioxide and air-assisted steam shale oil optimization system provided in an embodiment of the present application Figure 1 ;

[0049] Figure 2 A schematic diagram of a carbon dioxide and air-assisted steam shale oil optimization system provided in an embodiment of the present application Figure 2 .

[0050] Reference numerals:

[0051] 100-Optimization system for CO2 and air-assisted steam stimulation of shale oil;

[0052] 1-carbon dioxide storage tank; 2-air storage tank; 3-sealed distilled water container; 4-shale oil intermediate container; 5-water intermediate container; 6-proppant intermediate container; 7-constant speed and pressure pump; 8-steam generator; 9-thermogravimetric analyzer; 10-triaxial experimental equipment; 11-waste liquid collection device; 12-separation device; 13-first metering pump; 14-second metering pump; 15-third metering pump; 16-pressure sensor; 17-temperature sensor; 18-computer; 19-first stop valve; 20-second stop valve valve; 21-third stop valve; 22-fourth stop valve; 23-fifth stop valve; 24-sixth stop valve; 25-seventh stop valve; 26-eighth stop valve; 27-ninth stop valve; 28-tenth stop valve; 29-eleventh stop valve; 30-twelfth stop valve; 31-thirteenth stop valve; 32-fourteenth stop valve; 33-fifteenth stop valve; 34-sixteenth stop valve; 35-seventeenth stop valve; 36-eighteenth stop valve; 37-nineteenth stop valve; 38-twentieth stop valve;

[0053] 101-confining pressure chamber; 102-axial pressure chamber; 103-heating device; 104-silicone sleeve; 105-hydraulic loading unit. DETAILED DESCRIPTION

[0054] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0055] In the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with basically the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way. In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more.

[0056] It should be noted that the "at..." in the embodiments of the present application can be the instant when a certain situation occurs, or can be a period of time after a certain situation occurs, and the embodiments of the present application do not specifically limit this. In addition, the optimization system for shale oil with carbon dioxide and air-assisted steam is provided in the embodiments of the present application only as an example, and the optimization system for shale oil with carbon dioxide and air-assisted steam can also include more or less content.

[0057] In the existing technology, steam huff and puff technology is based on single-well operation and is easy to implement on site. It has become a conventional means of exploiting low-maturity shale oil reservoirs. However, as the exploitation process deepens, steam huff and puff faces problems such as high energy consumption, high cost, low efficiency, increased process complexity, and serious environmental pollution. Other replacement technologies need to be adopted in the middle and late stages of steam huff and puff. Generally, gas-assisted steam huff and puff is added, such as carbon dioxide and air.

[0058] Carbon dioxide-assisted steam huff and puff in tight oil reservoirs has been applied to a certain extent in the field and has achieved good results. A large number of experimental studies have shown that carbon dioxide-assisted steam huff and puff in tight oil reservoirs can further improve the recovery rate. However, carbon dioxide uses its physical properties to assist steam extraction of crude oil. For medium and low maturity shale oil reservoirs, hydrothermal cracking during steam injection can generally only partially split and decompose the recombinant into light components, and the degree of hydrothermal cracking reaction is limited.

[0059] my country has conducted field tests of air-assisted steam thermal recovery in Xinjiang, Tuha and Bohai oil fields, and achieved good results. The air-assisted process involves chemical reactions between crude oil and oxygen. The oxidation reaction mechanisms involved in different air injection technologies are different. At present, only single air-assisted steam huff and puff research is conducted, and the impact of CO2-air combined assisted steam huff and puff on the exploitation of medium- and low-maturity shale reservoirs is still unknown.

[0060] The gas-assisted steam stimulation shale oil experimental device in the prior art cannot test the effect of carbon dioxide-air on the steam stimulation of shale oil, nor can it find the factors affecting the improvement of shale oil recovery rate, shale oil extraction efficiency and energy utilization rate.

[0061] Based on this, in order to solve the above technical problems, the embodiment of the present application provides an optimization system for carbon dioxide and air-assisted steam shale oil, which can be used in the field of shale oil reservoir exploitation. The inventive concept of the present application is: how to effectively improve the efficiency of carbon dioxide and air-assisted steam shale oil.

[0062] Figure 1 A schematic diagram of a carbon dioxide and air-assisted steam shale oil optimization system provided in an embodiment of the present application. Figure 1As shown, the optimization system 100 for carbon dioxide and air-assisted steam absorption and exhalation of shale oil includes: a carbon dioxide storage tank 1, an air storage tank 2, a sealed distilled water container 3, a shale oil intermediate container 4, a water intermediate container 5, a proppant intermediate container 6, a constant speed and pressure pump 7, a steam generator 8, a thermogravimetric analyzer 9 and a triaxial experimental device 10.

[0063] The constant speed and constant pressure pump 7 is connected to the carbon dioxide storage tank 1 , and the constant speed and constant pressure pump 7 is used to liquefy the gaseous carbon dioxide in the carbon dioxide storage tank 1 .

[0064] The constant speed and constant pressure pump 7 is also connected to the air storage tank 2, the shale oil intermediate container 4, the water intermediate container 5 and the proppant intermediate container 6 respectively, and is used to transmit air, shale oil, water and proppant.

[0065] The sealed distilled water container 3 is connected to a constant speed and constant pressure pump 7 .

[0066] The steam generator 8 is connected to the sealed distilled water container 3, and the steam generator 8 is used to vaporize the distilled water in the sealed distilled water container 3 to generate water vapor.

[0067] The liquid in the sealed distilled water container 3 is distilled water, which is used to generate water vapor, and the liquid in the water intermediate container 5 is water, which is directly injected into the triaxial experimental equipment 10 for reaction.

[0068] The triaxial experimental device 10 is connected to the constant speed and constant pressure pump 7 and the steam generator 8 respectively, and the triaxial experimental device 10 is used to perform a throughput reaction.

[0069] Among them, the triaxial experimental equipment 10 performs a huff-and-puff reaction to generate product shale oil.

[0070] Thermogravimetric analyzer 9 is connected to carbon dioxide storage tank 1, air storage tank 2 and steam generator 8 respectively, and thermogravimetric analyzer 9 is used to perform gas injection ratio optimization experiment.

[0071] The product shale oil is divided into a plurality of samples of equal mass, and placed in a thermogravimetric analyzer 9 to carry out a gas injection ratio optimization experiment to optimize the gas injection ratio.

[0072] The present embodiment provides an optimization system for carbon dioxide and air-assisted steam absorption and exhalation of shale oil, the system comprising: a carbon dioxide storage tank 1, an air storage tank 2, a sealed distilled water container 3, a shale oil intermediate container 4, a water intermediate container 5, a proppant intermediate container 6, a constant speed and pressure pump 7, a steam generator 8, a thermogravimetric analyzer 9 and a triaxial experimental device 10; the constant speed and pressure pump 7 is connected to the carbon dioxide storage tank 1, and the constant speed and pressure pump 7 is used to liquefy the gaseous carbon dioxide in the carbon dioxide storage tank 1; the constant speed and pressure pump 7 is also connected to the air storage tank 2, the shale oil intermediate container 4, the water intermediate container 5, the proppant intermediate container 6, the constant speed and pressure pump 7, the steam generator 8, the thermogravimetric analyzer 9 and the ... The intermediate container 4, the water intermediate container 5 and the proppant intermediate container 6 are connected, and the sealed distilled water container 3 is connected to the constant speed and pressure pump 7; the steam generator 8 is connected to the sealed distilled water container 3, and the steam generator 8 is used to vaporize the distilled water in the sealed distilled water container 3; the triaxial experimental equipment 10 is respectively connected to the constant speed and pressure pump 7 and the steam generator 8, and the triaxial experimental equipment 10 is used to perform a huff-and-puff reaction; the thermogravimetric analyzer 9 is respectively connected to the carbon dioxide storage tank 1, the air storage tank 2 and the steam generator 8, and the thermogravimetric analyzer 9 is used to perform a gas injection ratio optimization experiment. This application uses a triaxial experimental equipment and a thermogravimetric analyzer to study the effect of the injection ratio of carbon dioxide, air, and steam on the shale oil recovery rate during the shale oil exploitation process by first fracturing and then repeating the huff-and-puff experiment. Real-time monitoring of the mass changes of the reactants, dynamic regulation of the injection ratio of carbon dioxide, air, and steam, so as to find a gas injection ratio that can greatly improve the recovery rate of shale oil, shale oil mining efficiency, and energy utilization, thereby optimizing the efficiency of carbon dioxide and air-assisted steam huff-and-puff.

[0073] A specific embodiment is used below to explain in detail a carbon dioxide and air-assisted steam throughput optimization system for shale oil provided in the present application.

[0074] like Figure 1 As shown, the system also includes: a waste liquid collecting device 11, a separation device 12, a first metering pump 13, a second metering pump 14, a third metering pump 15, a pressure sensor 16, a temperature sensor 17, a computer 18, a first stop valve 19, a second stop valve 20, a third stop valve 21, a fourth stop valve 22, a fifth stop valve 23, a sixth stop valve 24, a seventh stop valve 25, an eighth stop valve 26, a ninth stop valve 27, a tenth stop valve 28, an eleventh stop valve 29, a twelfth stop valve 30, a thirteenth stop valve 31, a fourteenth stop valve 32, a fifteenth stop valve 33, a sixteenth stop valve 34 and a seventeenth stop valve 35.

[0075] The triaxial test equipment 10 includes: a confining pressure chamber 101 , an axial pressure chamber 102 , a heating device 103 , a silicone sleeve 104 and a hydraulic loading unit 105 .

[0076] like Figure 1As shown, in a preferred embodiment, the triaxial test device 10 is also used to perform a fracturing reaction on the rock sample in the triaxial test device 10 by injecting liquid carbon dioxide through the constant speed and constant pressure pump 7 .

[0077] When the fracturing reaction is carried out, the first stop valve 19 , the third stop valve 21 , the fourth stop valve 22 and the eighth stop valve 26 are closed; and the fifth stop valve 23 , the sixth stop valve 24 and the seventh stop valve 25 are opened.

[0078] Specifically, the gaseous carbon dioxide in the carbon dioxide storage tank 1 is injected into the constant speed and pressure pump 7 through the second metering pump 14. The constant speed and pressure pump 7 pressurizes and liquefies the gaseous carbon dioxide to generate liquid carbon dioxide, and injects the liquid carbon dioxide into the triaxial test device 10, so that the liquid carbon dioxide performs a fracturing reaction on the rock sample in the triaxial test device 10.

[0079] Specifically, waste liquid is generated during the fracturing reaction, and the waste liquid is discharged from the triaxial test equipment 10 to the waste liquid collection device 11 .

[0080] More specifically, the gaseous carbon dioxide in the carbon dioxide storage tank 1 enters the pipeline through the first port of the twelfth stop valve 30, enters the first port of the eleventh stop valve 29 through the second port of the twelfth stop valve 30, enters the first port of the second metering pump 14 through the second port of the eleventh stop valve 29, enters the first port of the constant speed and constant pressure pump 7 through the second port of the second metering pump 14, and liquefies into liquid carbon dioxide in the constant speed and constant pressure pump 7. The liquid carbon dioxide enters the first port of the fifth stop valve 23 through the second port of the constant speed and constant pressure pump 7, enters the first port of the sixth stop valve 24 through the second port of the fifth stop valve 23, and enters the first port of the triaxial experimental device 10 through the second port of the sixth stop valve 24.

[0081] The second port of the second metering pump 14 and the first port of the constant speed and constant pressure pump 7 may be equipped with an intermediate device for connecting the second metering pump 14 and the constant speed and constant pressure pump 7 .

[0082] More specifically, the waste liquid generated in the fracturing reaction enters the first port of the seventh stop valve 25 through the second port of the triaxial test device 10 , and enters the waste liquid collection device 11 through the second port of the seventh stop valve 25 .

[0083] In addition, the injection rate of liquid carbon dioxide is 3 ml / min; the rock sample size is 15 mm*15 mm*30 mm.

[0084] It should be noted that before the fracturing reaction, it is necessary to select a rock sample of appropriate size, place the rock sample in the triaxial test equipment, fix the triaxial test equipment, and connect other experimental devices.

[0085] Furthermore, it is necessary to close all valves, check the air tightness of the pipelines, and ensure that the triaxial test equipment 10 is in a sealed state through vacuum operation.

[0086] like Figure 1 As shown, in another preferred embodiment, the triaxial test device 10 is also used to form a complex fracture network in the rock sample by injecting proppant through the constant speed and constant pressure pump 7 during the fracturing reaction.

[0087] When the proppant is injected, the fifth stop valve 23 and the eighth stop valve 26 are closed, and the first stop valve 19, the fourth stop valve 22 and the seventh stop valve 25 are opened.

[0088] Specifically, the proppant in the proppant intermediate container 6 is injected into the first metering pump 13 through the constant speed constant pressure pump 7. The first metering pump 13 injects the proppant into the triaxial test device 10, so that the proppant forms a complex fracture network in the rock sample.

[0089] Specifically, waste liquid is generated when the proppant forms a complex fracture network in the rock sample, and the waste liquid is discharged from the triaxial test equipment 10 to the waste liquid collection device 11 .

[0090] More specifically, the proppant in the proppant intermediate container 6 enters the pipeline through the first port of the thirteenth stop valve 31, enters the first port of the fourth stop valve 22 through the second port of the thirteenth stop valve 31, enters the second port of the constant speed and constant pressure pump 7 through the second port of the fourth stop valve 22, enters the first port of the constant speed and constant pressure pump 7 through the first port of the constant speed and constant pressure pump 7, enters the first port of the first stop valve 19 through the first port of the first stop valve 19, enters the first port of the sealed distilled water container 3 through the second port of the sealed distilled water container 3, enters the first port of the second stop valve 20 through the second port of the second stop valve 20, enters the first port of the first metering pump 13 through the second port of the first metering pump 13, enters the first port of the third stop valve 21 through the second port of the third stop valve 21, and enters the first port of the triaxial experimental equipment 10 through the second port of the third stop valve 21.

[0091] More specifically, the waste liquid generated when the proppant forms a complex fracture network in the rock sample enters the first port of the seventh stop valve 25 through the second port of the triaxial test equipment 10 , and enters the waste liquid collection device 11 through the second port of the seventh stop valve 25 .

[0092] like Figure 1 As shown, in another preferred embodiment, the triaxial test apparatus 10 is also used to perform a saturation reaction on the rock sample in the triaxial test apparatus 10 by injecting water and shale oil through the constant speed and constant pressure pump 7 .

[0093] When water and shale oil are injected, the third stop valve 21 , the fifth stop valve 23 and the eighth stop valve 26 are closed, and the first stop valve 19 , the fourth stop valve 22 and the seventh stop valve 25 are opened.

[0094] Specifically, the shale oil and water in the shale oil intermediate container 4 and the water intermediate container 5 are respectively injected into the second metering pump 14 through the constant speed constant pressure pump 7. The second metering pump 14 injects the shale oil and water into the third metering pump 15. The third metering pump 15 injects the shale oil and water into the triaxial test device 10, so that the shale oil and water react saturatedly with the rock sample in the triaxial test device 10.

[0095] Specifically, waste liquid is generated during the saturation reaction of the shale oil and water on the rock sample, and the waste liquid is discharged from the triaxial test equipment 10 to the waste liquid collection device 11 .

[0096] More specifically, the shale oil in the shale oil intermediate container 4 enters the pipeline through the first port of the fifteenth stop valve 33, and the shale oil enters the first port of the fourth stop valve 22 through the second port of the fifteenth stop valve 33; the water in the water intermediate container 5 enters the pipeline through the first port of the fourteenth stop valve 32, and the water enters the first port of the fourth stop valve 22 through the second port of the fourteenth stop valve 32.

[0097] More specifically, shale oil and water respectively enter the second port of the constant speed and constant pressure pump 7 through the second port of the fourth stop valve 22, enter the second port of the second metering pump 14 through the first port of the constant speed and constant pressure pump 7, enter the second port of the eleventh stop valve 29 through the first port of the second metering pump 14, enter the first port of the tenth stop valve 28 through the first port of the eleventh stop valve 29, enter the first port of the third metering pump 15 through the second port of the tenth stop valve 28, enter the first port of the third metering pump 15 through the second port of the third metering pump 15, and enter the first port of the ninth stop valve 27 through the second port of the ninth stop valve 27. Enter the first port of the triaxial experimental equipment 10 through the second port of the ninth stop valve 27.

[0098] More specifically, the waste liquid generated by the saturation reaction of shale oil and water on the rock sample enters the first port of the seventh stop valve 25 through the second port of the triaxial experimental equipment 10, and enters the waste liquid collection device 11 through the second port of the seventh stop valve 25.

[0099] In addition, water and shale oil were injected into the rock samples sequentially at an injection rate of 2 ml / min.

[0100] like Figure 1 As shown, in another preferred embodiment, formation conditions are simulated in a triaxial test apparatus 10 .

[0101] The triaxial test equipment 10 further includes: a confining pressure chamber 101 , an axial pressure chamber 102 , a heating device 103 , a silicone sleeve 104 and a hydraulic loading unit 105 .

[0102] The system further includes: a pressure sensor 16 , a temperature sensor 17 and a computer 18 .

[0103] Specifically, the rock sample in the triaxial experimental equipment 10 is preheated by the heating device 103, and the temperature change of the rock sample is monitored in real time by observing the temperature sensor 17, so that the temperature of the rock sample reaches a preset experimental temperature (such as a rock sample temperature of 60°C), and the experimental temperature of the rock sample is stabilized for 15 minutes to simulate the formation temperature.

[0104] Specifically, axial pressure and confining pressure are applied to the rock sample through the hydraulic loading unit 105, and the pressure changes of the confining pressure chamber 101 and the axial pressure chamber 102 are monitored in real time by observing the pressure sensor 16, so that the pressures of the confining pressure chamber 101 and the axial pressure chamber 102 reach the preset experimental pressure (axial pressure 30 MPa, confining pressure 25 MPa) to simulate the formation pressure.

[0105] It should be noted that the silicone sleeve 104 is used to ensure the sealing of the triaxial test device 10 .

[0106] Furthermore, the silicone sleeve 104 is also used to transfer the axial pressure and confining pressure applied by the confining pressure chamber 101 and the axial pressure chamber 102 to the rock sample evenly and stably.

[0107] Furthermore, the silicone sleeve 104 is also used to maintain the temperature of the rock sample and has a heat preservation effect.

[0108] like Figure 1 As shown, in another preferred embodiment, the triaxial experimental equipment 10 is also used to simulate the well-sealing state in the triaxial experimental equipment 10 by injecting carbon dioxide gas, air and steam through the first metering pump 13, the second metering pump 14 and the constant speed and pressure pump 7 according to the initial gas injection ratio.

[0109] When carbon dioxide gas, air and steam are injected, the first stop valve 19, the fourth stop valve 22 and the seventh stop valve 25 are closed, and the third stop valve 21, the fifth stop valve 23 and the sixth stop valve 24 are opened.

[0110] When injecting gas, the gas is injected in the order of air, carbon dioxide gas and steam.

[0111] Specifically, the carbon dioxide gas and air in the carbon dioxide storage tank 1 and the air storage tank 2 are injected into the constant speed and constant pressure pump 7 through the second metering pump 14. The constant speed and constant pressure pump 7 injects the carbon dioxide gas and air into the third metering pump 15. The third metering pump 15 injects the carbon dioxide gas and air into the triaxial experimental equipment 10 to simulate the well-simmering state.

[0112] More specifically, the carbon dioxide gas in the carbon dioxide storage tank 1 enters the pipeline through the first port of the twelfth stop valve 30, and the carbon dioxide gas enters the first port of the eleventh stop valve 29 through the second port of the twelfth stop valve 30; the air in the air storage tank 2 enters the pipeline through the first port of the sixteenth stop valve 34, and the air enters the first port of the eleventh stop valve 29 through the second port of the sixteenth stop valve 34.

[0113] More specifically, the carbon dioxide gas and air respectively enter the first port of the second metering pump 14 through the second port of the eleventh stop valve 29, enter the first port of the constant speed and constant pressure pump 7 through the second port of the second metering pump 14, enter the first port of the constant speed and constant pressure pump 7 at the second port of the constant speed and constant pressure pump 7, enter the first port of the fifth stop valve 23 through the second port of the fifth stop valve 23, enter the first port of the sixth stop valve 24 through the second port of the sixth stop valve 24, and enter the first port of the triaxial experimental equipment 10 through the second port of the sixth stop valve 24.

[0114] Specifically, the liquid distilled water in the sealed distilled water container 3 is heated and vaporized by the steam generator 8 to generate steam. The steam generator 8 injects the steam into the first metering pump 13. The first metering pump 13 injects the steam into the triaxial experimental device 10 to simulate the well stewing state.

[0115] More specifically, the liquid distilled water in the sealed distilled water container 3 enters the first port of the second stop valve 20 through the second port of the sealed distilled water container 3, enters the first port of the steam generator 8 through the second port of the second stop valve 20, and is heated and vaporized into steam in the steam generator 8. The steam enters the first port of the first metering pump 13 through the second port of the first metering pump 13, enters the first port of the third stop valve 21 through the second port of the first metering pump 13, and is injected into the first port of the triaxial experimental device 10 through the second port of the third stop valve 21.

[0116] In addition, the gas volume calculation formula for carbon dioxide gas, air and steam that needs to be injected under formation conditions is:

[0117]

[0118] Among them, V1 ′ is the volume of carbon dioxide at formation conditions; V2 ′ is the volume of air under formation conditions; V3 ′ is the volume of steam at formation conditions; V1 is the volume of carbon dioxide in the thermogravimetric analyzer; V2 is the volume of air in the thermogravimetric analyzer; V3 is the volume of steam in the thermogravimetric analyzer; P1 ′ is the pressure under formation conditions; Z1 ′ It is P1 ′compression factor at 0.1MPa; P1 is 0.1MPa; Z1 is the compression factor at 0.1MPa; T1 ′ is the temperature at formation conditions; T1 is the temperature in the thermogravimetric analyzer.

[0119] It should be noted that when the gas volumes of the injected carbon dioxide gas, air and steam reach the preset gas injection ratio, the injection is stopped, the third stop valve 21, the sixth stop valve 24 and the eighth stop valve 26 are closed, the well-suffocating state is simulated, and the well-suffocating reaction is started.

[0120] It should also be noted that after the well-simmering reaction is completed, the eighth stop valve 26 is opened, and the products generated in the well-simmering reaction are discharged from the triaxial experimental equipment 10 to the separation device 12 to separate the products generated in the well-simmering reaction.

[0121] Specifically, the product generated in the soaking reaction enters the first port of the eighth stop valve 26 through the first port of the triaxial experimental equipment 10, enters the first port of the separation device 12 through the second port of the eighth stop valve 26, and is separated in the separation device 12 to obtain product shale oil.

[0122] like Figure 1 As shown, in another preferred embodiment, the thermogravimetric analyzer 9 is used to perform a gas injection ratio optimization experiment on the shale oil sample by injecting air, carbon dioxide gas and steam through the first metering pump 13 and the third metering pump 15 according to a preset gas injection ratio.

[0123] When carbon dioxide gas, air and steam are injected, the first stop valve 19, the eleventh stop valve 29 and the eighth stop valve 26 are closed, and the second stop valve 20, the third stop valve 21, the ninth stop valve 27 and the tenth stop valve 28 are opened.

[0124] When each shale oil sample is injected with a first volume of steam, a second volume of air, and a third volume of carbon dioxide gas, the gases are injected in the order of air, carbon dioxide gas, and steam. The ratio of the first volume, the second volume, and the third volume is a preset gas injection ratio.

[0125] Specifically, the carbon dioxide gas and air in the carbon dioxide storage tank 1 and the air storage tank 2 are injected into the thermogravimetric analyzer 9 through the third metering pump 15 .

[0126] More specifically, the carbon dioxide gas in the carbon dioxide storage tank 1 enters the pipeline through the first port of the twelfth stop valve 30, and the carbon dioxide gas enters the first port of the tenth stop valve 28 through the second port of the twelfth stop valve 30; the air in the air storage tank 2 enters the pipeline through the first port of the sixteenth stop valve 34, and the air enters the first port of the tenth stop valve 28 through the second port of the sixteenth stop valve 34.

[0127] More specifically, the carbon dioxide gas and air respectively enter the first port of the third metering pump 15 through the second port of the tenth stop valve 28 , and enter the first port of the thermogravimetric analyzer 9 through the second port of the third metering pump 15 .

[0128] Specifically, the liquid distilled water in the sealed distilled water container 3 is heated and vaporized by the steam generator 8 to generate steam. The steam generator 8 injects the steam into the first metering pump 13. The first metering pump 13 injects the steam into the thermogravimetric analyzer 9.

[0129] More specifically, the liquid distilled water in the sealed distilled water container 3 enters the first port of the second stop valve 20 through the second port of the sealed distilled water container 3, enters the first port of the steam generator 8 through the second port of the second stop valve 20, and is heated and vaporized into steam in the steam generator 8. The steam enters the first port of the first metering pump 13 through the second port of the first metering pump 13, enters the first port of the third stop valve 21 through the second port of the first metering pump 13, enters the second port of the ninth stop valve 27 through the second port of the third stop valve 21, and is injected into the first port of the thermogravimetric analyzer 9 through the first port of the ninth stop valve 27.

[0130] It should be noted that before conducting the gas injection ratio optimization experiment in the thermogravimetric analyzer 9, the collected product shale oil needs to be divided into multiple shale oil samples and placed in the thermogravimetric analyzer 9. The mass of the shale oil sample used in each experiment is 3-5 mg.

[0131] It should also be noted that after the gas injection of each shale oil sample is completed, the experimental temperature (such as the experimental temperature is 25-600°C), the experimental pressure (such as the experimental pressure is 0.1MPa) and the heating rate (such as the heating rate is 15°C / min) need to be adjusted by the thermogravimetric analyzer 9.

[0132] Specifically, the temperature is continuously raised by the thermogravimetric analyzer 9, and the mass change of each shale oil sample before and after the reaction at different temperatures is measured by the thermogravimetric analyzer 9, and the real-time data displayed by the computer 18 is read at the same time.

[0133] Furthermore, the computer 18 obtains a relationship curve between the weight loss rate and temperature of each shale oil sample based on real-time data, thereby determining the extent of the reaction and establishing a relationship between the reaction progress and the gas injection ratio.

[0134] Among them, the reaction progress formula is:

[0135]

[0136] Where a is the reaction progress; m0 is the initial shale oil sample mass; m t is the mass of shale oil sample at time t; m∞ is the mass of shale oil sample at the end of reaction.

[0137] Furthermore, when the computer 18 determines that the reaction is complete, the gas injection ratio is adjusted, and the steam is injected and the temperature is increased again for the next shale oil sample.

[0138] Furthermore, steam injection and temperature increase operations are performed on each shale oil sample, and the computer 18 obtains a target injection ratio that can improve the throughput efficiency of carbon dioxide and air-assisted steam based on real-time data.

[0139] In addition, based on the target injection ratio, the triaxial test apparatus 10 data and the mine field data, a similarity relationship between the triaxial test apparatus 10 and the mine field is established.

[0140] First, establish a size similarity relationship:

[0141]

[0142] Among them, X2 is the length of the mine; X1 is the length of the three-axis device; It is the scale ratio of the mine and the three-axis device.

[0143] Then, a similarity relationship of gas injection amount is established:

[0144]

[0145] in, is the gas mass flow rate at the mine site; is the gas mass flow rate of the triaxial device; n v is the similarity index.

[0146] Furthermore, the computer 18 obtains a curve of the relationship between the weight loss rate and the temperature corresponding to the target injection ratio based on the real-time data, and divides the different oxidation reaction stages according to the curve to obtain a refined temperature range for each oxidation reaction stage.

[0147] In this embodiment, a triaxial experimental device is used to simulate the formation environment. The triaxial experimental device and a thermogravimetric analyzer are used to implement a fracturing followed by repeated throughput experiment. The thermogravimetric analysis experiment is used to determine the refined temperature range corresponding to different oxidation reactions of shale oil samples under continuous heating conditions. At the same time, the influence of the injection ratio of carbon dioxide gas, air and steam on the shale oil recovery rate in the process of shale oil production by combined carbon dioxide and air-assisted steam throughput is studied, so as to find the gas injection ratio that can greatly improve the shale oil recovery rate, shale oil production efficiency and energy utilization, and then optimize the efficiency of carbon dioxide and air-assisted steam throughput.

[0148] Figure 2A schematic diagram of a carbon dioxide and air-assisted steam shale oil optimization system provided in an embodiment of the present application Figure 2 ,like Figure 2 As shown, in a preferred embodiment, an eighteenth stop valve 36 is installed above the shale oil intermediate container 4; a nineteenth stop valve 37 is installed above the water intermediate container 5; and a twentieth stop valve 38 is installed above the proppant intermediate container 6.

[0149] like Figure 2 As shown, in another preferred embodiment, the triaxial test apparatus 10 is also used to form a complex fracture network in a rock sample by proppant pushed by distilled water during a fracturing reaction.

[0150] When injecting the proppant, the fifth stop valve 23, the eighth stop valve 26, the eighteenth stop valve 36, the nineteenth stop valve 37, the fourteenth stop valve 32 and the fifteenth stop valve 33 are closed, and the first stop valve 19, the fourth stop valve 22, the twentieth stop valve 38, the thirteenth stop valve 31 and the seventh stop valve 25 are opened.

[0151] Specifically, the distilled water in the sealed distilled water container 3 is pressurized and injected into the proppant intermediate container 6 by the constant speed constant pressure pump 7. The distilled water pushes the proppant into the triaxial test device 10, so that the proppant forms a complex fracture network in the rock sample.

[0152] Specifically, waste liquid is generated when the proppant forms a complex fracture network in the rock sample, and the waste liquid is discharged from the triaxial test equipment 10 to the waste liquid collection device 11 .

[0153] More specifically, the distilled water in the sealed distilled water container 3 is pressurized by the constant speed and constant pressure pump 7, enters the second port of the first stop valve 19 from the first port of the sealed distilled water container 3, enters the first port of the constant speed and constant pressure pump 7 through the first port of the first stop valve 19, enters the first port of the constant speed and constant pressure pump 7 through the second port of the constant speed and constant pressure pump 7, enters the first port of the fourth stop valve 22 through the second port of the fourth stop valve 22, enters the second port of the thirteenth stop valve 31, enters the proppant intermediate container 6 through the first port of the thirteenth stop valve 31, and the distilled water pushes the proppant into the first port of the twentieth stop valve 38, enters the first port of the sixth stop valve 24 through the second port of the twentieth stop valve 38, and enters the first port of the triaxial experimental equipment 10 through the second port of the sixth stop valve 24.

[0154] More specifically, the waste liquid generated when the proppant forms a complex fracture network in the rock sample enters the first port of the seventh stop valve 25 through the second port of the triaxial test equipment 10 , and enters the waste liquid collection device 11 through the second port of the seventh stop valve 25 .

[0155] like Figure 2As shown, in another preferred embodiment, the triaxial test apparatus 10 is also used to perform a saturation reaction between the water pushed in by distilled water and the rock sample in the triaxial test apparatus 10 .

[0156] When water is injected, the third stop valve 21, the fifth stop valve 23, the fifteenth stop valve 33, the eighteenth stop valve 36, the twentieth stop valve 38, the thirteenth stop valve 31 and the eighth stop valve 26 are closed, and the first stop valve 19, the fourth stop valve 22, the seventh stop valve 25, the nineteenth stop valve 37 and the fourteenth stop valve 32 are opened.

[0157] Specifically, the distilled water in the sealed distilled water container 3 is pressurized and injected into the water intermediate container 5 by the constant speed constant pressure pump 7. The distilled water pushes the water into the triaxial test device 10, so that the water performs a saturation reaction on the rock sample in the triaxial test device 10.

[0158] Specifically, waste liquid is generated during the saturation reaction of water on the rock sample, and the waste liquid is discharged from the triaxial test equipment 10 to the waste liquid collection device 11 .

[0159] More specifically, the distilled water in the sealed distilled water container 3 is pressurized by the constant speed and constant pressure pump 7, enters the second port of the first stop valve 19 from the first port of the sealed distilled water container 3, enters the first port of the constant speed and constant pressure pump 7 through the first port of the first stop valve 19, enters the first port of the constant speed and constant pressure pump 7 through the second port of the constant speed and constant pressure pump 7, enters the first port of the fourth stop valve 22 through the second port of the fourth stop valve 22, enters the second port of the fourteenth stop valve 32, enters the water intermediate container 5 through the first port of the fourteenth stop valve 32, and the distilled water pushes the aqueous solution into the first port of the nineteenth stop valve 37, enters the first port of the sixth stop valve 24 through the second port of the nineteenth stop valve 37, and enters the first port of the triaxial experimental equipment 10 through the second port of the sixth stop valve 24.

[0160] More specifically, the waste liquid generated by the saturation reaction of water on the rock sample enters the first port of the seventh stop valve 25 through the second port of the triaxial test equipment 10 and enters the waste liquid collection device 11 through the second port of the seventh stop valve 25 .

[0161] like Figure 2 As shown, in another preferred embodiment, the triaxial test apparatus 10 is also used to carry out a saturation reaction between shale oil pushed in by distilled water and the rock sample in the triaxial test apparatus 10 .

[0162] Among them, when injecting shale oil, the third stop valve 21, the fifth stop valve 23, the twentieth stop valve 38, the thirteenth stop valve 31, the nineteenth stop valve 37, the fourteenth stop valve 32 and the eighth stop valve 26 are closed, and the first stop valve 19, the fourth stop valve 22, the seventh stop valve 25, the fifteenth stop valve 33 and the eighteenth stop valve 36 are opened.

[0163] Specifically, the distilled water in the sealed distilled water container 3 is pressurized and injected into the shale oil intermediate container 4 through the constant speed constant pressure pump 7. The distilled water pushes the shale oil into the triaxial test device 10, so that the shale oil reacts saturatedly with the rock sample in the triaxial test device 10.

[0164] Specifically, waste liquid is generated during the saturation reaction of shale oil on the rock sample, and the waste liquid is discharged from the triaxial test equipment 10 to the waste liquid collection device 11 .

[0165] More specifically, the distilled water in the sealed distilled water container 3 is pressurized by the constant speed and constant pressure pump 7, enters the second port of the first stop valve 19 from the first port of the sealed distilled water container 3, enters the first port of the constant speed and constant pressure pump 7 through the first port of the first stop valve 19, enters the first port of the constant speed and constant pressure pump 7 through the second port of the constant speed and constant pressure pump 7, enters the first port of the fourth stop valve 22 through the second port of the fourth stop valve 22, enters the second port of the fifteenth stop valve 33, enters the shale oil intermediate container 4 through the first port of the fifteenth stop valve 33, and the distilled water pushes the shale oil into the first port of the eighteenth stop valve 36, enters the first port of the sixth stop valve 24 through the second port of the eighteenth stop valve 36, and enters the first port of the triaxial experimental equipment 10 through the second port of the sixth stop valve 24.

[0166] More specifically, the waste liquid generated by the saturation reaction of shale oil on the rock sample enters the first port of the seventh stop valve 25 through the second port of the triaxial experimental equipment 10 and enters the waste liquid collection device 11 through the second port of the seventh stop valve 25 .

[0167] In this embodiment, a triaxial test device and a thermogravimetric analyzer are used to conduct repeated throughput experiments after fracturing to study the effect of the injection ratio of carbon dioxide, air, and steam on the shale oil recovery rate during shale oil production. The quality changes of the reactants are monitored in real time, and the injection ratio of carbon dioxide, air, and steam is dynamically adjusted to find a gas injection ratio that can significantly improve the shale oil recovery rate, shale oil production efficiency, and energy utilization, thereby optimizing the efficiency of carbon dioxide and air-assisted steam throughput.

[0168] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments, and the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A carbon dioxide and air-assisted steam stimulation and exhalation optimization system for shale oil, characterized in that: The system comprises: a carbon dioxide storage tank (1), an air storage tank (2), a sealed distilled water container (3), a shale oil intermediate container (4), a water intermediate container (5), a proppant intermediate container (6), a constant speed and pressure pump (7), a steam generator (8), a thermogravimetric analyzer (9) and a triaxial experimental device (10); The constant speed and constant pressure pump (7) is connected to the carbon dioxide storage tank (1), and the constant speed and constant pressure pump (7) is used to liquefy the gaseous carbon dioxide in the carbon dioxide storage tank (1); The constant speed and constant pressure pump (7) is also connected to the air storage tank (2), the shale oil intermediate container (4), the water intermediate container (5) and the proppant intermediate container (6) respectively, and the sealed distilled water container (3) is connected to the constant speed and constant pressure pump (7); The steam generator (8) is connected to the sealed distilled water container (3), and the steam generator (8) is used to vaporize the distilled water in the sealed distilled water container (3); The triaxial experimental device (10) is connected to the constant speed and constant pressure pump (7) and the steam generator (8) respectively, and the triaxial experimental device (10) is used to perform a throughput reaction; The thermogravimetric analyzer (9) is connected to the carbon dioxide storage tank (1), the air storage tank (2) and the steam generator (8) respectively, and the thermogravimetric analyzer (9) is used to perform a gas injection ratio optimization experiment.

2. The system according to claim 1, characterized in that The triaxial test device (10) is also used to perform a fracturing reaction on the rock sample in the triaxial test device (10) by injecting liquid carbon dioxide through the constant speed and constant pressure pump (7); The system further comprises: a twelfth stop valve (30), an eleventh stop valve (29), a fifth stop valve (23), a sixth stop valve (24), a seventh stop valve (25) and a waste liquid collection device (11); The first port of the twelfth stop valve (30) is connected to the carbon dioxide storage tank (1); The first port of the eleventh stop valve (29) is connected to the second port of the twelfth stop valve (30), and the first port of the constant speed constant pressure pump (7) is connected to the second port of the eleventh stop valve (29); The first port of the fifth stop valve (23) is connected to the second port of the constant speed constant pressure pump (7), the first port of the sixth stop valve (24) is connected to the second port of the fifth stop valve (23), and the first port of the triaxial experimental device (10) is connected to the second port of the sixth stop valve (24); The first port of the seventh stop valve (25) is connected to the second port of the triaxial test equipment (10), and the waste liquid collection device (11) is connected to the second port of the seventh stop valve (25). The waste liquid collection device (11) is used to collect the waste liquid generated by the fracturing reaction in the triaxial test equipment (10).

3. The system according to claim 2, characterized in that The triaxial test device (10) is also used to form a complex fracture network in the rock sample by injecting a proppant through the constant speed and constant pressure pump (7) during the fracturing reaction; The system further comprises: a first stop valve (19), a second stop valve (20), a third stop valve (21), a fourth stop valve (22) and a thirteenth stop valve (31); The first port of the thirteenth stop valve (31) is connected to the proppant intermediate container (16), the first port of the fourth stop valve (22) is connected to the second port of the thirteenth stop valve (31), the second port of the constant speed and constant pressure pump (7) is connected to the second port of the fourth stop valve (22), the first port of the first stop valve (19) is connected to the first port of the constant speed and constant pressure pump (7), the first port of the sealed distilled water container (1) is connected to the second port of the first stop valve (19), the first port of the second stop valve (20) is connected to the second port of the sealed distilled water container (1), the first port of the steam generator (5) is connected to the second port of the second stop valve (20), the first port of the third stop valve (21) is connected to the second port of the steam generator (5), and the first port of the triaxial test device (10) is connected to the second port of the third stop valve (21); The waste liquid collecting device (11) is used to collect waste liquid generated when a complex fracture network is formed in the rock sample.

4. The system according to claim 3, characterized in that The triaxial test device (10) is also used to perform a saturation reaction on the rock sample in the triaxial test device (10) by injecting water and shale oil through the constant speed and constant pressure pump (7); The system further comprises: a ninth stop valve (27), a tenth stop valve (28), a fourteenth stop valve (32) and a fifteenth stop valve (33); The first port of the fourteenth stop valve (32) is connected to the water intermediate container (15); the first port of the fifteenth stop valve (33) is connected to the shale oil intermediate container (14); the first port of the fourth stop valve (22) is connected to the second port of the fourteenth stop valve (32) and the second port of the fifteenth stop valve (33) respectively; The first port of the tenth stop valve (28) is connected to the first port of the eleventh stop valve (34), the first port of the ninth stop valve (27) is connected to the second port of the tenth stop valve (28); the first port of the triaxial test device (10) is connected to the second port of the ninth stop valve (27); The waste liquid collecting device (11) is used to collect the waste liquid generated by the saturated reaction in the triaxial experimental device (10).

5. The system according to claim 4, characterized in that The system further comprises: a sixteenth stop valve (34), a first metering pump (13) and a second metering pump (14); The first port of the first metering pump (13) is connected to the second port of the steam generator (5), and the first port of the third stop valve (21) is connected to the second port of the first metering pump (13); The first port of the sixteenth stop valve (34) is connected to the air storage tank (8), the first port of the eleventh stop valve (34) is connected to the second port of the sixteenth stop valve (34), the first port of the second metering pump (14) is connected to the second port of the eleventh stop valve (34); and the first port of the constant speed and constant pressure pump (7) is connected to the second port of the second metering pump (14).

6. The system according to claim 5, characterized in that When the first stop valve (19), the third stop valve (21), the fourth stop valve (22), the sixth stop valve (24) and the seventh stop valve (25) are closed, the triaxial test device (10) is also used to perform a well-simmering reaction on the rock sample in the triaxial test device (10) by means of steam injected by the first metering pump (13) and carbon dioxide and air injected by the second metering pump (14).

7. The system according to claim 6, characterized in that The system further comprises: an eighth stop valve (26), a separation device (12) and a seventeenth stop valve (35); The first port of the eighth stop valve (26) is connected to the first port of the triaxial test device (10), and the first port of the separation device (12) is connected to the second port of the eighth stop valve (26); After the steaming reaction is completed, the separation device (12) is used to separate the product generated by the steaming reaction in the triaxial test device (10); The first port of the seventeenth stop valve (35) is connected to the first port of the thermogravimetric analyzer (9), and the second port of the separation device (12) is connected to the second port of the seventeenth stop valve (35).

8. The system according to claim 7, characterized in that The system further comprises: a third metering pump (15); The second port of the ninth stop valve (27) is connected to the second port of the third stop valve (21), and the second port of the thermogravimetric analyzer (9) is connected to the first port of the ninth stop valve (27); The first port of the third metering pump (15) is connected to the second port of the tenth stop valve (28), and the second port of the thermogravimetric analyzer (9) is connected to the second port of the third metering pump (15); The thermogravimetric analyzer (9) is also used to inject a first volume of steam through the first metering pump (13), and inject a second volume of air and a third volume of carbon dioxide through the third metering pump (15), to perform a gas injection ratio optimization experiment on the shale oil sample in the thermogravimetric analyzer (9); wherein the ratio of the first volume to the second volume to the third volume is a preset ratio.

9. The system according to claim 8, characterized in that The triaxial test equipment (10) further comprises: a confining pressure chamber (101), an axial pressure chamber (102), a heating device (103), a silicone sleeve (104) and a hydraulic loading unit (105); The hydraulic loading unit (105) is used to apply confining pressure to the confining pressure chamber (101), and to connect and apply axial pressure to the axial pressure chamber (102) to simulate formation conditions; The heating device (103) is used to heat the rock sample.

10. The system according to claim 9, characterized in that The system further comprises: a pressure sensor (16), a temperature sensor (17) and a computer (18); The computer (18) is used to control the hydraulic loading unit (105) to apply confining pressure and axial pressure; The temperature sensor (17) is used to monitor the temperature of the rock sample, and the pressure sensor (16) is used to monitor the pressure of the confining pressure and the axial pressure.

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