CN111579463A

CN111579463A - Physical simulation device for storing carbon dioxide in water and gas reservoir and simulation method thereof

Info

Publication number: CN111579463A
Application number: CN202010601735.5A
Authority: CN
Inventors: 汤勇; 胡世莱; 廖松林; 杨光宇; 龙科吉; 何佑伟; 汪勇; 侯承希
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2020-08-25
Anticipated expiration: 2040-06-29
Also published as: CN111579463B

Abstract

The invention provides a physical simulation device and a simulation method for carbon dioxide stored in a water-gas reservoir, wherein the device is arranged in a heat preservation box, and a constant-temperature heating system is also arranged in the heat preservation box and used for heating the physical simulation device for carbon dioxide stored in the water-gas reservoir to the original formation temperature of a target waste gas reservoir; the simulation device comprises two gas storage steel cylinders, a gas compressor, five electronic pressure gauges, eleven needle valves, three constant-speed constant-pressure pumps, four middle pressure containers, two hand pumps, a six-way valve, a vacuum pump, a vacuum pressure gauge, a rock core holder, a three-way valve, a back pressure valve and a waste liquid tank. The invention can realize the change characteristics and rules of the storage space and the flow capacity after the carbon dioxide is injected into the gas layer and the water layer of the water-gas reservoir, thereby providing more comprehensive and more reliable basis for formulating a reasonable implementation technical scheme for storing the carbon dioxide with the water-gas reservoir.

Description

Physical simulation device for storing carbon dioxide in water and gas reservoir and simulation method thereof

Technical Field

The invention belongs to the technical field of petroleum and natural gas industry and geological carbon dioxide sequestration, and particularly relates to a physical simulation device and a physical simulation method suitable for the storage space and the flow capacity change characteristics and rules of carbon dioxide in the process of storing carbon dioxide in a water-gas reservoir.

Background

With the rapid development of socioeconomic, fossil energy consumption is continuously rising, resulting in the annual increase in atmospheric carbon dioxide concentration. According to the latest report of the International Energy Agency (IEA), the global carbon dioxide concentration is raised to a brand new height, which is as high as 412 ppm. In order to reduce the concentration of carbon dioxide in the atmosphere and achieve the aim of controlling the global temperature rise within 2 ℃ at the end of the century, human measures must be adopted to intervene. Currently, carbon dioxide capture and sequestration (CCS) has become a globally recognized technology for effectively controlling the concentration of carbon dioxide in the atmosphere. The key technology is that the trapped artificial carbon dioxide is injected into the underground geological structure, so that the carbon dioxide is permanently sealed in the underground. Currently, geological formations suitable for sequestration of carbon dioxide include primarily subterranean aquifers and abandoned subterranean hydrocarbon reservoirs. Because the abandoned underground oil and gas reservoir has perfect ground gas injection facilities and sufficient underground gas storage space, particularly the abandoned oil and gas reservoir has larger underground gas storage space. Therefore, compared with a ground water layer and a waste oil reservoir, the waste gas reservoir has more advantages as a carbon dioxide sealing and storing place.

Because waste gas reservoirs generally contain large amounts of formation water, in addition carbon dioxide can react with water to produce carbonic acid. Therefore, after being injected into a gas reservoir, the carbon dioxide can generate chemical reaction with formation rock minerals, so that the rock minerals are dissolved, moved and re-precipitated, and the pore space and the flow channel of the formation rock are changed, thereby influencing the storage space and the flow capacity of the carbon dioxide. Therefore, before the project of sealing and storing the carbon dioxide by the abandoned water-gas reservoir is implemented, corresponding indoor physical simulation research must be carried out to obtain the storage space and the flow capacity change characteristics and rules of the carbon dioxide in the process of sealing and storing the carbon dioxide by the water-gas reservoir, so that a reliable basis is provided for formulating the geological carbon dioxide storage scheme. Because the existing method can only singly simulate the condition that carbon dioxide is injected into the underground water layer, can not simulate the characteristics of the carbon dioxide injected into the underground gas layer and the underground water layer at the same time, and can not compare the variation characteristics and the law of the storage space and the flow capacity after the carbon dioxide is injected into the gas layer and the water layer, the full and comprehensive experimental knowledge is difficult to obtain. In view of this, it is needed to design and establish a physical simulation device and a simulation method for water-gas-reservoir-sealed carbon dioxide, so that the indoor physical simulation experiment result can comprehensively reflect the change characteristics and rules of the underground gas storage space and the flow capacity after the carbon dioxide is injected into the water reservoir, and the change difference between the gas layer and the water layer after the carbon dioxide is injected into the water reservoir, thereby providing a more comprehensive and reliable basis for formulating a reasonable implementation technical scheme for water-gas-reservoir-sealed carbon dioxide.

Disclosure of Invention

In view of the above problems, the present invention provides a physical simulation apparatus and a simulation method thereof for carbon dioxide stored in a water reservoir, which are particularly suitable for the characteristics and laws of changes in storage space and flow capacity of carbon dioxide during the process of storing carbon dioxide in the water reservoir, and the differences in changes between a gas layer and a water layer after carbon dioxide is injected into the water reservoir.

The physical simulation device for the carbon dioxide stored in the water gas reservoir is arranged in the heat insulation box, and the constant temperature heating system is also arranged in the heat insulation box and used for heating the physical simulation device for the carbon dioxide stored in the water gas reservoir to the original formation temperature of the target waste gas reservoir; the simulation device specifically comprises a six-way valve, wherein a valve b of the six-way valve is used for pressure relief; the valve c of the six-way valve is connected with a second electronic pressure gauge; the d valve of the six-way valve is connected with a rock core holder through a pipeline, the rock core holder is sequentially connected with a third electronic pressure gauge, a tenth needle valve and a first hand pump through a pipeline, the rock core holder is also connected with a valve a of a three-way valve through a pipeline, a valve b of the three-way valve is sequentially connected with an eleventh needle valve, a vacuum pressure gauge and a vacuum pump through a pipeline, a valve c of the three-way valve is sequentially connected with a fourth electronic pressure gauge, a back pressure valve and a waste liquid tank through a pipeline, and the back pressure valve is sequentially connected with a fifth electronic pressure gauge and a second hand pump through; the e valve of the six-way valve is sequentially connected with a fourth needle valve, a third pressure-resistant intermediate container, an eighth needle valve and a second constant-speed constant-pressure pump through pipelines, and the third pressure-resistant intermediate container is also sequentially connected with a fifth needle valve, a fourth pressure-resistant intermediate container, a ninth needle valve and a third constant-speed constant-pressure pump through pipelines; the third pressure-resistant intermediate container is filled with formation water and hydraulic oil which are separated by a second piston, and the fourth pressure-resistant intermediate container is filled with carbon dioxide and hydraulic oil which are separated by a third piston; the f valve of the six-way valve is sequentially connected with a third needle valve, a second pressure-resistant intermediate container, a seventh needle valve, a second needle valve, a first pressure-resistant intermediate container, a sixth needle valve and a first constant-speed constant-pressure pump through pipelines, the first pressure-resistant intermediate container is further sequentially connected with a first needle valve, a first electronic pressure gauge, a gas compressor and a first gas storage steel cylinder through pipelines, and the first gas storage steel cylinder stores the compound gas of carbon dioxide and natural gas; the first pressure-resistant intermediate container is filled with pressurized repeated air and hydraulic oil separated by a first piston, and the second pressure-resistant intermediate container is filled with formation water.

Preferably, a rotating bracket is fixed to the third pressure-resistant intermediate container to rotate the third pressure-resistant intermediate container, and a fixing bracket is fixed to each of the first pressure-resistant intermediate container, the second pressure-resistant intermediate container, and the fourth pressure-resistant intermediate container.

Preferably, the valve a of the six-way valve is connected with a second gas storage steel cylinder through a pipeline, and nitrogen is filled in the second gas storage steel cylinder.

The simulation method for carrying out repeated gas displacement of saturated water by utilizing the physical simulation device for storing carbon dioxide in the water reservoir comprises the following steps:

step S1: testing initial porosity of experimental core by using core hole seepage joint tester

And initial permeability k_i11；

Step S2: the pressure of the repeated gas in the first gas storage steel cylinder is increased to the original formation pressure P of the target waste gas reservoir by the gas compressor₀Opening a first needle valve, and storing the boosted compound gas in a first pressure-resistant intermediate container;

step S3: filling formation water of the target waste gas reservoir into a second pressure-resistant intermediate container; wherein the volume of the formation water accounts for 1/2 to 3/4 of the volume of the second pressure-resistant intermediate container;

step S4: opening the a valve and the d valve of the six-way valve and the a valve and the c valve of the three-way valve, flushing the physical simulation device with the water gas reservoir and the sealed carbon dioxide by using the nitrogen in the second gas storage steel cylinder, closing all the valves, checking the gas tightness of the device, starting the constant temperature heating system, and setting the heating temperature as the original formation temperature T of the target waste gas reservoir₀；

Step S5: loading the experimental rock core into a rock core holder, opening a valve d of a six-way valve, a valve a and a valve b of a three-way valve and an eleventh needle valve, starting a vacuum pump to vacuumize, keeping the temperature for more than 1 hour, and enabling the temperature of the physical simulation device for storing carbon dioxide by water and gas reservoir to reach the set temperature T₀；

Step S6: closing the d valve of the six-way valve, the a and b valves of the three-way valve and the eleventh needle valve, starting the second manual pump, and increasing the pressure of the back pressure valve to P₀Opening a tenth needle valve, starting a first hand pump, and lifting the confining pressure of the rock core holder to P₀+2MPa；

Step S7: opening the second needle valve, the third needle valve, the sixth needle valve, the seventh needle valve, the c valve, the d valve and the f valve of the six-way valve and the a valve and the c valve of the three-way valve, starting the first constant-speed constant-pressure pump, enabling the compound gas of the saturated water to pass through the experimental rock core at a constant flow rate for more than 48 hours, and enabling the compound gas of the experimental rock core and the saturated water to fully react until the inlet pressure displayed by the second electronic pressure gauge is stable;

step S8: closing the first constant-speed constant-pressure pump, the second needle valve, the third needle valve, the sixth needle valve and the seventh needle valve, opening the valve b of the six-way valve for pressure relief, closing the valves, and then closing the valves c and f of the six-way valve and the valve c of the three-way valve;

step S9: opening an eleventh needle valve and a valve b of a three-way valve, starting a vacuum pump to vacuumize, releasing confining pressure of the core holder, taking out an experimental core from the core holder, and closing the eleventh needle valve, the valves a and b of the three-way valve and a valve d of a six-way valve;

step S10: testing porosity of experimental core after repeated gas displacement simulation by using core hole seepage tester

And permeability k_f11Calculating the porosity change rate and the permeability change rate of the experimental core after the repeated gas displacement simulation according to the following formula:

R_k11＝(k_f11-k_i11)/k_i11×100％；

wherein the content of the first and second substances,

the change rate of the porosity of the experimental rock core after the compound gas displacement simulation, R_k11The change rate of the permeability of the experimental rock core after the compound gas displacement simulation is shown.

Preferably, the compound gas is configured according to the following formula:

V_CO2:V_NG＝(G_o-G_a):G_a

in the formula: v_CO2Is the volume of carbon dioxide in the reconstituted gas; v_NGIs the volume of natural gas in the compound gas; g_oIs the original natural gas reserve of the target waste gas reservoir; g_aIs the waste natural gas reserve of the target waste gas reservoir.

The simulation method for repeated gas soaking of saturated water by using the physical simulation device for storing carbon dioxide in the water reservoir comprises the following steps:

And initial permeability k_i12；

Step S7: opening the c, d and f valves of the second needle valve, the third needle valve, the sixth needle valve, the seventh needle valve and the six-way valve, starting the first constant-speed and constant-pressure pump, and setting the pressure to be P₀Soaking the experimental core in the repeated distribution of the saturated water for more than 48 hours to ensure that the repeated distribution of the saturated water and the experimental core fully react;

step S8: closing the first constant-speed constant-pressure pump, the second needle valve, the third needle valve, the sixth needle valve and the seventh needle valve, opening the valve b of the six-way valve to release pressure, closing the valves, and then closing the valves c and f of the six-way valve;

step S9: opening an eleventh needle valve, an a valve and a b valve of a three-way valve, starting a vacuum pump to vacuumize, releasing confining pressure of the core holder, taking out an experimental core from the core holder, and closing the eleventh needle valve, the a valve and the b valve of the three-way valve and a d valve of a six-way valve;

step S10: testing porosity of experimental rock core after repeated gas soaking simulation by adopting rock core hole seepage joint tester

And permeability k_f12Calculating the porosity change rate and the permeability change rate of the experimental rock core after the repeated gas soaking simulation according to the following formula:

R_k12＝(k_f12-k_i12)/k_i12×100％；

wherein the content of the first and second substances,

the change rate of the porosity of the experimental rock core after the simulation of the compound gas soaking, R_k12The change rate of the permeability of the experimental rock core after the compound gas soaking simulation is shown.

Preferably, the compound gas is configured according to the following formula:

V_CO2:V_NG＝(G_o-G_a):G_a

The simulation method for carrying out the stratum water displacement of saturated carbon dioxide by using the physical simulation device for storing carbon dioxide in the water gas reservoir comprises the following steps:

And initial permeability k_i21；

Step S2: filling formation water of the target waste gas reservoir into a third pressure-resistant intermediate container; wherein the volume of the formation water accounts for 1/2 to 3/4 of the volume of the third pressure-resistant intermediate container;

step S3: opening the fifth needle valve and the ninth needle valve, and pumping the mixture at a constant pressure P by a third constant-speed constant-pressure pump₀Transferring carbon dioxide in the fourth pressure-resistant intermediate container into the third pressure-resistant intermediate container at constant pressure, fully mixing the formation water and the carbon dioxide in the third pressure-resistant intermediate container in a rotary stirring manner, opening an eighth needle valve, starting a second constant-speed constant-pressure pump, and performing constant-pressure treatment at constant pressure P₀Releasing gaseous carbon dioxide in the third pressure-resistant intermediate container for later use;

Step S7: opening a fourth needle valve, an eighth needle valve, c, d and e valves of the six-way valve and a valve a and c valves of the three-way valve, starting a second constant-speed constant-pressure pump, enabling the formation water saturated with carbon dioxide to pass through the experimental core at a constant flow rate for more than 48 hours, and enabling the experimental core to fully react with the formation water saturated with carbon dioxide until the inlet pressure displayed by the second electronic pressure gauge is stable;

step S8: closing the second constant-speed constant-pressure pump, the fourth needle valve and the eighth needle valve, opening a valve b of the six-way valve for pressure relief, closing the valves, and then closing a valve c and a valve e of the six-way valve and a valve c of the three-way valve;

step S10: testing porosity of experimental core after formation water displacement simulation by using core hole seepage coupling tester

And permeability k_f21Calculating the porosity change rate and the permeability change rate of the experimental core after the formation water displacement simulation according to the following formula:

R_k21＝(k_f21-k_i21)/k_i21×100％；

wherein the content of the first and second substances,

the change rate of porosity, R, of the experimental core after formation water displacement simulation_k21The change rate of the permeability of the experimental core after the formation water displacement simulation is shown.

A simulation method for soaking formation water of saturated carbon dioxide by using a physical simulation device for storing carbon dioxide in a water-gas reservoir comprises the following steps:

step S1: using rocksInitial porosity of core in core hole seepage tester test experiment

And initial permeability k_i22；

Step S7: opening the c, d and e valves of the fourth needle valve, the eighth needle valve and the six-way valve, starting the second constant-speed constant-pressure pump, and setting the pressure to be P₀To make the experimental core be fullSoaking the carbon dioxide-saturated formation water for more than 48 hours to enable the carbon dioxide-saturated formation water to fully react with the experimental core;

step S8: closing the second constant-speed constant-pressure pump, the fourth needle valve and the eighth needle valve, opening a valve b of the six-way valve to release pressure, closing the valves, and then closing a valve c of the six-way valve;

step S10: testing porosity of experimental rock core after formation water soaking simulation by adopting rock core hole seepage joint tester

And permeability k_f22Calculating the porosity change rate and the permeability change rate of the experimental rock core after the formation water soaking simulation according to the following formulas:

R_k22＝(k_f22-k_i22)/k_i22×100％；

wherein the content of the first and second substances,

the change rate of porosity, R, of the simulated experimental core after formation water immersion_k22The change rate of the permeability of the experimental core after the formation water soaking simulation is shown.

By utilizing the physical simulation device and the simulation method for the carbon dioxide with the water vapor reservoir, the change characteristics and the change rules of the storage space and the flow capacity after the carbon dioxide is injected into the gas layer and the water layer of the water vapor reservoir can be simulated simultaneously, and the change difference between the gas layer and the water layer and the change difference between the carbon dioxide in the injection state and the carbon dioxide in the storage state can be compared. Meanwhile, by changing experimental simulation conditions, the influence of gas injection process parameters (including pressure, temperature, gas injection speed, total gas injection amount, sealing time and the like) of the water-gas-reservoir-buried carbon dioxide on the storage space and the flow capacity of the carbon dioxide can be researched, so that a more comprehensive and reliable basis is provided for formulating a reasonable implementation technical scheme for sealing the carbon dioxide with the water-gas reservoir.

Drawings

Other objects and results of the present invention will become more apparent and more readily appreciated as the same becomes better understood by reference to the following description and appended claims, taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 is a schematic structural diagram of a physical simulation apparatus for storing carbon dioxide with a water-gas reservoir according to an embodiment of the invention.

Wherein the reference numerals include: 1-1 parts of first gas storage steel cylinder, 1-2 parts of second gas storage steel cylinder, 2 parts of compound gas, 3 parts of gas compressor, 4-1-4-5 parts of first to fifth electronic pressure gauges, 5-1-5-11 parts of first to eleventh needle valves, 6 parts of nitrogen, 7-1-7-3 parts of first to third constant-speed constant-pressure pumps, 8-1-8-4 parts of first to fourth pressure-resistant intermediate containers, 9-1-9-3 parts of first to third pistons, 10 parts of hydraulic oil, 11-1-11-3 parts of first to third fixed supports, 12 parts of formation water, 13 parts of rotating support, 14 parts of carbon dioxide, 15-1 parts of first hand shaking pump, 15-2 parts of second hand shaking pressure gauge pump, 16 parts of six-way valve, 17 parts of vacuum pump, 18 parts of vacuum pump, 19 parts of core holder, 19 parts of rock core holder, and the like, Three-way valve 20, back pressure valve 21, waste liquid jar 22, insulation can 23, constant temperature heating system 24.

The same reference numbers in all figures indicate similar or corresponding features or functions.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows the structure of a physical simulation device for storing carbon dioxide with a water-gas reservoir according to an embodiment of the invention.

As shown in fig. 1, the physical simulation apparatus for storing carbon dioxide with a water vapor reservoir provided in the embodiment of the present invention is disposed in an insulation box 23, a constant temperature heating system 24 is further disposed in the insulation box 23, and the constant temperature heating system 24 is configured to heat the physical simulation apparatus for storing carbon dioxide with a water vapor reservoir to an original formation temperature of a target waste gas reservoir.

The simulation device specifically comprises: 1-1 parts of first gas storage steel cylinder, 1-2 parts of second gas storage steel cylinder, 2 parts of compound gas, 3 parts of gas compressor, 4-1-4-5 parts of first to fifth electronic pressure gauges, 5-1-5-11 parts of first to eleventh needle valves, 6 parts of nitrogen, 7-1-7-3 parts of first to third constant-speed constant-pressure pumps, 8-1-8-4 parts of first to fourth pressure-resistant intermediate containers, 9-1-9-3 parts of first to third pistons, 10 parts of hydraulic oil, 11-1-11-3 parts of first to third fixed supports, 12 parts of formation water, 13 parts of rotating support, 14 parts of carbon dioxide, 15-1 parts of first hand shaking pump, 15-2 parts of second hand shaking pressure gauge pump, 16 parts of six-way valve, 17 parts of vacuum pump, 18 parts of vacuum pump, 19 parts of core holder, 19 parts of rock core holder, and the like, A three-way valve 20, a back-pressure valve 21 and a waste liquid tank 22.

The valve a of the six-way valve 16 is connected with a second gas storage steel cylinder 1-2 through a pipeline, and nitrogen 6 is filled in the second gas storage steel cylinder 1-2; the b valve of the six-way valve 16 is used for pressure relief; the valve c of the six-way valve 16 is connected with a second electronic pressure gauge 4-2; the d valve of the six-way valve 16 is connected with a rock core holder 19 through a pipeline, the rock core holder 19 is sequentially connected with a third electronic pressure gauge 4-3, a tenth needle valve 5-10 and a first hand pump 15-1 through a pipeline, the rock core holder 19 is also connected with a valve a of a three-way valve 20 through a pipeline, a valve b of the three-way valve 20 is sequentially connected with an eleventh needle valve 5-11, a vacuum pressure gauge 18 and a vacuum pump 17 through a pipeline, a valve c of the three-way valve 20 is sequentially connected with a fourth electronic pressure gauge 4-4, a back pressure valve 21 and a waste liquid tank 22 through a pipeline, and the back pressure valve 21 is sequentially connected with a fifth electronic pressure gauge 4-5 and a second hand pump 15-2 through a; the e valve of the six-way valve 16 is sequentially connected with a fourth needle valve 5-4, a third pressure-resistant intermediate container 8-3, an eighth needle valve 5-8 and a second constant-speed constant-pressure pump 7-2 through pipelines, and the third pressure-resistant intermediate container 8-3 is further sequentially connected with a fifth needle valve 5-5, a fourth pressure-resistant intermediate container 8-4, a ninth needle valve 5-9 and a third constant-speed constant-pressure pump 7-3 through pipelines; formation water 12 and hydraulic oil 10 separated by a second piston 9-2 are contained in a third pressure-resistant intermediate container 8-3, and carbon dioxide 14 and hydraulic oil 10 separated by the third piston 9-3 are contained in a fourth pressure-resistant intermediate container 8-4; the f valve of the six-way valve 16 is sequentially connected with a third needle valve 5-3, a second pressure-resistant intermediate container 8-2, a seventh needle valve 5-7, a second needle valve 5-2, a first pressure-resistant intermediate container 8-1, a sixth needle valve 5-6 and a first constant-speed constant-pressure pump 7-1 through pipelines, the first pressure-resistant intermediate container 8-1 is further sequentially connected with a first needle valve 5-1, a first electronic pressure gauge 4-1, a gas compressor 3 and a first gas storage steel cylinder 1-1 through pipelines, and the first gas storage steel cylinder 1-1 stores the compound gas 2 of carbon dioxide and natural gas; the first pressure-resistant intermediate container 8-1 is filled with pressurized compound gas 2 and hydraulic oil 10 separated by a first piston 9-1, and the second pressure-resistant intermediate container 8-2 is filled with formation water 12.

A rotating bracket 13 is fixed to the third pressure-resistant intermediate vessel 8-3 to rotate the third pressure-resistant intermediate vessel 8-3, and a fixing bracket 11 is fixed to each of the first pressure-resistant intermediate vessel 8-1, the second pressure-resistant intermediate vessel 8-2, and the fourth pressure-resistant intermediate vessel 8-4 to fix each pressure-resistant intermediate vessel.

The above details describe the structure of the physical simulation apparatus for storing carbon dioxide with a water gas reservoir provided by the present invention, and the apparatus can realize a compound gas displacement simulation experiment of saturated water (simulating the process of injecting carbon dioxide into the gas layer of the water gas reservoir), a compound gas soaking simulation experiment of saturated water (simulating the process of sealing the gas layer of the water gas reservoir with carbon dioxide), a formation water displacement simulation experiment of saturated carbon dioxide, a formation water saturation simulation experiment of saturated carbon dioxide (simulating the process of injecting carbon dioxide into the water layer of the water gas reservoir), and a formation water soaking simulation experiment of saturated carbon dioxide (simulating the process of sealing the water layer of the water gas reservoir with carbon dioxide).

The experimental core is divided into I, II grades and III grades, each 2 experimental cores of the same grade are respectively used for experiments of different fluids (the same core needs to be cut into 2 experimental cores with the same size and are respectively used for different types of experiments), the experimental cores are numbered, and the numbering rule is core grade-experimental fluid-experimental type, for example, as shown in Table 1:

table 1 experimental core number example

In the table, I, II, and III represent core grades, G represents a compound gas in which the test fluid is saturated water, W represents formation water in which the test fluid is saturated carbon dioxide, 1 represents a displacement test, and 2 represents a soaking test.

The initial porosity and initial permeability of the experimental core were measured using the core hole tool disclosed in application No. 201920866685.6.

It should be noted that the porosity and permeability respectively represent the size of the gas storage space and the flow capacity of the experimental core.

Compound gas displacement experiment of saturated water

The compound gas displacement experiment of saturated water comprises the following steps:

step S101: the method comprises the following steps of preparing compound gas 2 of carbon dioxide and natural gas required by a simulation experiment, calculating the ratio of the carbon dioxide to the natural gas according to a formula (1), wherein the common gas distribution pressure is 15MPa, and the compound gas 2 is stored in a first gas storage steel cylinder 1-1:

V_CO2:V_NG＝(G_o-G_a):G_a(1)

in formula (1): v_CO2Is the volume of carbon dioxide in the compound gas 2; v_NGThe volume of the natural gas in the compound gas 2; g_oIs the original natural gas reserve of the target waste gas reservoir; g_aIs the waste natural gas reserve of the target waste gas reservoir.

Step S102: the pressure of the repeated gas 2 in the first gas storage steel cylinder 1-1 is increased to the original formation pressure P of the target waste gas reservoir by the gas compressor 3₀Then, the first needle valve 5-1 is opened, and the pressurized compound gas is stored in the first pressure-resistant intermediate container 8-1.

Step S103: formation water 12 of the target waste gas reservoir is charged into the second pressure-resistant intermediate vessel 8-2, and the volume of the formation water 12 in the second pressure-resistant intermediate vessel 8-2 accounts for 1/2 to 3/4 of the volume of the second pressure-resistant intermediate vessel 8-2.

Step S104: opening the a and d valves of the six-way valve 16 and the a and c valves of the three-way valve 20, flushing the simulation device with the nitrogen gas 6 in the second gas cylinder 6-2, closing all the valves after flushing, checking the airtightness of the device, then starting the constant temperature heating system 24, and setting the heating temperature to be the original formation temperature T of the target waste gas reservoir₀。

Step S105: testing initial porosity of experimental rock core with rock core number I-G-1 by adopting rock core hole seepage joint tester

And initial permeability k_i11。

Step S106: loading the experimental rock core with the rock core number I-G-1 into a rock core holder 19, opening a valve d of a six-way valve 16, opening valves a and b of a three-way valve 20, opening an eleventh needle valve 5-11, starting a vacuum pump 17 to vacuumize, keeping the temperature for more than 1 hour, and enabling the temperature of the device to reach the set temperature T₀。

Step S107: all opened valves are closed, the second manual pump 15-2 is started, and the pressure of the back pressure valve 21 is increased to P₀Opening a tenth needle valve 5-10, starting a first hand pump 15-1, and raising the confining pressure of the core holder 19 to P₀+2MPa。

Step S108: and opening the second needle valve 5-2, the third needle valve 5-3, the sixth needle valve 5-6 and the seventh needle valve 5-7, opening the c, d and f valves of the six-way valve 16, opening the a and c valves of the three-way valve 20, and communicating the repeated gas displacement device.

Step S109: starting a constant speed mode of a first constant speed and constant pressure pump 7-1, setting the flow rate to be 1ml/min, enabling the compound gas 2 of the saturated water to pass through the experimental core at a constant flow rate for more than 48 hours, enabling the experimental core to fully react with the compound gas 2 of the saturated water until the inlet pressure displayed by a second electronic pressure gauge 4-2 is stable, then closing the first constant speed and constant pressure pump 7-1, closing a second needle valve 5-2, a third needle valve 5-3, a sixth needle valve 5-6 and a seventh needle valve 5-7, opening a valve b of a six-way valve 16 for pressure relief, closing the valve b of the six-way valve 16 for pressure relief, finally closing a valve c and a valve f of the six-way valve 16 and a valve c of a three-way valve 20, and stopping the displacement experiment.

Step S110: and opening the eleventh needle valve 5-11, opening a valve b of the three-way valve 20, starting the vacuum pump 17 for vacuumizing, releasing confining pressure of the core holder 19, taking out the experimental core, closing all valves and cleaning the core holder 19.

Step S111: porosity of experimental rock core with rock core hole seepage joint tester tested rock core number I-G-1 after compound gas flooding replacement experiment

And permeability k_f11Calculating the porosity change rate and the permeability change rate of the experimental rock core after the compound gas flooding simulation of the saturated water according to the following formula:

R_k11＝(k_f11-k_i11)/k_i11×100％。

wherein the content of the first and second substances,

And (4) repeating the steps S101 to S111 to complete the compound gas flooding experiment of the saturated water of the experimental rock cores with the rock core numbers II-G-1 and III-G-1, and calculating the porosity change rate and the permeability change rate of the experimental rock cores with the rock core numbers II-G-1 and III-G-1 after the compound gas flooding simulation of the saturated water.

Second, compound air soaking experiment of saturated water

The compound air soaking experiment of saturated water comprises the following steps:

step S201: the method comprises the following steps of preparing compound gas 2 of carbon dioxide and natural gas required by a simulation experiment, calculating the ratio of the carbon dioxide to the natural gas according to a formula (2), wherein the common gas distribution pressure is 15MPa, and the compound gas 2 is stored in a first gas storage steel cylinder 1-1:

V_CO2:V_NG＝(G_o-G_a):G_a(2)

Step S202: the pressure of the repeated gas 2 in the first gas storage steel cylinder 1-1 is increased to the original formation pressure P of the target waste gas reservoir by the gas compressor 3₀Then, the first needle valve 5-1 is opened, and the pressurized compound gas is stored in the first pressure-resistant intermediate container 8-1.

Step S203: formation water 12 of the target waste gas reservoir is charged into the second pressure-resistant intermediate vessel 8-2, and the volume of the formation water 12 in the second pressure-resistant intermediate vessel 8-2 accounts for 1/2 to 3/4 of the volume of the second pressure-resistant intermediate vessel 8-2.

Step S204: opening the a and d valves of the six-way valve 16 and the a and c valves of the three-way valve 20, flushing the simulation device with the nitrogen gas 6 in the second gas cylinder 6-2, closing all the valves after flushing, checking the airtightness of the device, then starting the constant temperature heating system 24, and setting the heating temperature to be the original formation temperature T of the target waste gas reservoir₀。

Step S205: testing initial porosity of experimental rock core with rock core number I-G-2 by adopting rock core hole seepage joint tester

And initial permeability k_i12。

Step S206: loading the experimental rock core with the rock core number I-G-2 into a rock core holder 19, opening a valve d of a six-way valve 16, opening valves a and b of a three-way valve 20, opening an eleventh needle valve 5-11, starting a vacuum pump 17 to vacuumize, keeping the temperature for more than 1 hour, and enabling the temperature of the device to reach the set temperature T₀。

Step S207: closing all opened valves, starting the second manual pump 15-2, and pressing the back pressure valve 21Lifting force to P₀Opening a tenth needle valve 5-10, starting a first hand pump 15-1, and raising the confining pressure of the core holder 19 to P₀+2MPa。

Step S208: and opening a second needle valve 5-2, a third needle valve 5-3, a sixth needle valve 5-6 and a seventh needle valve 5-7, opening c, d and f valves of the six-way valve 16, opening a valve a and c valves of the three-way valve 20, and communicating the repeated gas soaking device.

Step S209: starting a constant pressure mode of a first constant speed and constant pressure pump 7-1, and setting the pressure to be P₀And soaking the experimental core in the compound gas of saturated water for more than 48 hours to ensure that the experimental core and the compound gas 2 of the saturated water fully react until the inlet pressure displayed by the second electronic pressure gauge 4-2 is stable, then closing the first constant-speed constant-pressure pump 7-1, closing the second needle valve 5-2, the third needle valve 5-3, the sixth needle valve 5-6 and the seventh needle valve 5-7, opening the b valve of the six-way valve 16 for pressure relief, closing the valves, finally closing the c valve and the f valve of the six-way valve 16 and the c valve of the three-way valve 20, and stopping the soaking experiment.

Step S210: and opening the eleventh needle valve 5-11, opening a valve b of the three-way valve 20, starting the vacuum pump 17 for vacuumizing, releasing confining pressure of the core holder 19, taking out the experimental core, closing all valves and cleaning the core holder 19.

Step S211: porosity of experimental rock core with rock core hole seepage joint tester tested rock core number I-G-2 after compound air soaking experiment

And permeability k_f12Calculating the porosity change rate and the permeability change rate of the experimental rock core after the compound gas soaking simulation of the saturated water according to the following formula:

R_k12＝(k_f12-k_i12)/k_i12×100％。

wherein the content of the first and second substances,

And repeating the steps S201 to S211 to complete the compound air soaking experiment of the saturated water of the experimental rock cores with the rock core numbers II-G-2 and III-G-2, and calculating the porosity change rate and the permeability change rate of the experimental rock cores with the rock core numbers II-G-2 and III-G-2 after the compound air soaking simulation of the saturated water.

Third, saturated carbon dioxide stratum water displacement experiment

The carbon dioxide saturated formation water displacement experiment comprises the following steps:

step S301: the formation water 12 of the target waste gas reservoir is filled into a third pressure-resistant intermediate container 8-3; wherein the volume of the formation water 12 occupies 1/2 to 3/4 of the volume of the third pressure-resistant intermediate vessel 8-3.

Step S302: opening the fifth needle valve 5-5 and the ninth needle valve 5-9, and constant pressure P is applied by the third constant speed and constant pressure pump 7-3₀ Transferring carbon dioxide 14 in a fourth pressure-resistant intermediate container 8-4 into a third pressure-resistant intermediate container 8-3 at a constant pressure, fully mixing formation water 12 and carbon dioxide 14 in the third pressure-resistant intermediate container 8-3 in a rotary stirring manner, opening an eighth needle valve 5-8, starting a second constant-speed constant-pressure pump 7-2, and performing constant-pressure P₀The gaseous carbon dioxide in the third pressure-resistant intermediate container 8-3 is released for standby.

Step S303: opening the a and d valves of the six-way valve 16 and the a and c valves of the three-way valve 20, flushing the physical simulation device with water gas reservoir and carbon dioxide stored by using the nitrogen gas 6 in the second gas storage steel cylinder 1-2, closing all the valves, checking the airtightness of the device, starting the constant temperature heating system 24, and setting the heating temperature to be the original formation temperature T of the target waste gas reservoir₀。

Step S304: testing initial porosity of experimental rock core with rock core number I-W-1 by adopting rock core hole seepage joint tester

And initiallyPermeability k_i21。

Step S305: loading the experimental rock core with the rock core number I-W-1 into a rock core holder 19, opening a valve d of a six-way valve 16, opening valves a and b of a three-way valve 20, opening an eleventh needle valve 5-11, starting a vacuum pump 17 to vacuumize, keeping the temperature for more than 1 hour, and enabling the temperature of the device to reach the set temperature T₀。

Step S306: all opened valves are closed, the second manual pump 15-2 is started, and the pressure of the back pressure valve 21 is increased to P₀Opening a tenth needle valve 5-10, starting a first hand pump 15-1, and raising the confining pressure of the core holder 19 to P₀+2MPa。

Step S307: and opening the second needle valve 5-2, the third needle valve 5-3, the sixth needle valve 5-6 and the seventh needle valve 5-7, opening the c, d and e valves of the six-way valve 16, opening the a and c valves of the three-way valve 20 and communicating the formation water displacement device.

Step S308: and starting a constant speed mode of a second constant speed and constant pressure pump 7-2, setting the flow rate to be 1ml/min, enabling the formation water 12 saturated with carbon dioxide to pass through the experimental core at the constant flow rate for more than 48 hours, enabling the formation water 12 saturated with carbon dioxide to fully react with the experimental core until the inlet pressure displayed by a second electronic pressure gauge 4-2 is stable, then closing the second constant speed and constant pressure pump 7-2, closing a fourth needle valve 5-4 and an eighth needle valve 5-8, opening a valve b of a six-way valve 16 for pressure relief, closing a valve c and a valve e of the six-way valve 16 and a valve c of a three-way valve 20, and stopping the displacement experiment.

Step S309: and opening the eleventh needle valve 5-11, opening a valve b of the three-way valve 20, starting the vacuum pump 17 for vacuumizing, releasing confining pressure of the core holder 19, taking out the experimental core, closing all valves and cleaning the core holder 19.

Step S310: testing porosity of experimental core after formation water displacement simulation by using core hole seepage coupling tester

And permeability k_f21Calculating the change rate of the porosity and the change rate of the permeability of the experimental rock core with the rock core number I-W-1 after the formation water displacement simulation according to the following formula：

R_k21＝(k_f21-k_i21)/k_i21×100％。

Wherein the content of the first and second substances,

And (5) repeating the steps S301 to S310 to complete the carbon dioxide saturated formation water displacement experiment of the experiment cores with the core numbers II-W-1 and III-W-1, and calculating the porosity change rate and the permeability change rate of the experiment cores with the core numbers II-W-1 and III-W-1 after the carbon dioxide saturated formation water displacement simulation.

Formation water soaking experiment of saturated carbon dioxide

The carbon dioxide saturated formation water soaking experiment comprises the following steps:

step S401: the formation water 12 of the target waste gas reservoir is filled into a third pressure-resistant intermediate container 8-3; wherein the volume of the formation water 12 occupies 1/2 to 3/4 of the volume of the third pressure-resistant intermediate vessel 8-3.

Step S402: opening the fifth needle valve 5-5 and the ninth needle valve 5-9, and constant pressure P is applied by the third constant speed and constant pressure pump 7-3₀ Transferring carbon dioxide 14 in a fourth pressure-resistant intermediate container 8-4 into a third pressure-resistant intermediate container 8-3 at a constant pressure, fully mixing formation water 12 and carbon dioxide 14 in the third pressure-resistant intermediate container 8-3 in a rotary stirring manner, opening an eighth needle valve 5-8, starting a second constant-speed constant-pressure pump 7-2, and performing constant-pressure P₀The gaseous carbon dioxide in the third pressure-resistant intermediate container 8-3 is released for standby.

Step S403: opening the a and d valves of the six-way valve 16 and the a and c valves of the three-way valve 20, flushing the physical simulation device with water vapor reservoir and sealed carbon dioxide by using the nitrogen gas 6 in the second gas storage cylinder 1-2Closing all valves, checking the airtightness of the device, starting the constant-temperature heating system 24, and setting the heating temperature to be the original formation temperature T of the target waste gas reservoir₀。

Step S404: testing initial porosity of experimental core by using core hole seepage joint tester

And initial permeability k_i22。

Step S405: loading the experimental rock core with the rock core number I-W-2 into a rock core holder 19, opening a valve d of a six-way valve 16, opening valves a and b of a three-way valve 20, opening an eleventh needle valve 5-11, starting a vacuum pump 17 to vacuumize, keeping the temperature for more than 1 hour, and enabling the temperature of the device to reach the set temperature T₀。

Step S406: all opened valves are closed, the second manual pump 15-2 is started, and the pressure of the back pressure valve 21 is increased to P₀Opening a tenth needle valve 5-10, starting a first hand pump 15-1, and raising the confining pressure of the core holder 19 to P₀+2MPa。

Step S407: and opening a second needle valve 5-2, a third needle valve 5-3, a sixth needle valve 5-6 and a seventh needle valve 5-7, opening c, d and e valves of the six-way valve 16, opening a and c valves of the three-way valve 20 and communicating the formation water soaking device.

Step S408: starting a second constant-speed constant-pressure pump 7-2 in a constant-pressure mode, and setting the pressure to be P₀Soaking the experimental core in the formation water 12 of the saturated carbon dioxide 14 for more than 48 hours to enable the formation water 12 of the saturated carbon dioxide 14 to fully react with the experimental core, fully reacting the formation water 12 of the saturated carbon dioxide 14 with the experimental core until the inlet pressure displayed by the second electronic pressure gauge 4-2 is stable, then closing the second constant-speed constant-pressure pump 7-2, closing the fourth needle valve 5-4 and the eighth needle valve 5-8, opening the b valve of the six-way valve 16 for pressure relief, closing the c valve and the e valve of the six-way valve 16 and the c valve of the three-way valve 20, and stopping the soaking experiment.

Step S409: and opening the eleventh needle valve 5-11, opening a valve b of the three-way valve 20, starting the vacuum pump 17 for vacuumizing, releasing confining pressure of the core holder 19, taking out the experimental core, closing all valves and cleaning the core holder 19.

Step S410: testing the porosity of the experimental rock core with the rock core number I-W-2 after the formation water soaking simulation by adopting a rock core hole seepage joint tester

R_k22＝(k_f22-k_i22)/k_i22×100％。

wherein the content of the first and second substances,

And (5) repeating the steps S401 to S410 to complete the carbon dioxide saturated formation water immersion experiment of the experiment cores with the core numbers II-W-2 and III-W-2, and calculating the porosity change rate and the permeability change rate of the experiment cores with the core numbers II-W-2 and III-W-2 after the experiment cores with the core numbers II-W-2 and III-W-2 are subjected to carbon dioxide saturated formation water immersion simulation.

And (3) comparing and analyzing the change conditions of the porosity and the permeability of the experimental rock core after the experiment, and researching the change characteristics and rules of the storage space and the flow capacity after carbon dioxide is injected into the gas layer and the water layer of the water-gas reservoir under different physical property conditions.

And comparing the change rate of the porosity and the permeability of the experimental core after the compound gas displacement/soaking experiment of saturated water and the formation water displacement/soaking experiment of saturated carbon dioxide, and determining the change difference between the carbon dioxide injected into the gas layer and the water layer respectively.

And comparing the change rate of the porosity and the permeability of the experimental rock core after the displacement experiment and the soaking experiment, and determining the change difference of the carbon dioxide between the injection state and the sealing state.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A physical simulation device for storing carbon dioxide by a water gas reservoir is characterized by being arranged in an insulation box, and a constant-temperature heating system is also arranged in the insulation box and used for heating the physical simulation device for storing carbon dioxide by the water gas reservoir to the original formation temperature of a target waste gas reservoir;

the physical simulation device for storing carbon dioxide with water and gas reserves comprises a six-way valve, wherein a valve b of the six-way valve is used for pressure relief; the valve c of the six-way valve is connected with a second electronic pressure gauge; the d valve of the six-way valve is connected with a rock core holder through a pipeline, the rock core holder is sequentially connected with a third electronic pressure gauge, a tenth needle valve and a first hand pump through a pipeline, the rock core holder is also connected with a valve a of a three-way valve through a pipeline, a valve b of the three-way valve is sequentially connected with an eleventh needle valve, a vacuum pressure gauge and a vacuum pump through a pipeline, a valve c of the three-way valve is sequentially connected with a fourth electronic pressure gauge, a back pressure valve and a waste liquid tank through a pipeline, and the back pressure valve is sequentially connected with a fifth electronic pressure gauge and a second hand pump through; the e valve of the six-way valve is sequentially connected with a fourth needle valve, a third pressure-resistant intermediate container, an eighth needle valve and a second constant-speed constant-pressure pump through pipelines, and the third pressure-resistant intermediate container is also sequentially connected with a fifth needle valve, a fourth pressure-resistant intermediate container, a ninth needle valve and a third constant-speed constant-pressure pump through pipelines; the third pressure-resistant intermediate container is filled with formation water and hydraulic oil which are separated by a second piston, and the fourth pressure-resistant intermediate container is filled with carbon dioxide and hydraulic oil which are separated by a third piston; the f valve of the six-way valve is sequentially connected with a third needle valve, a second pressure-resistant intermediate container, a seventh needle valve, a second needle valve, a first pressure-resistant intermediate container, a sixth needle valve and a first constant-speed constant-pressure pump through pipelines, the first pressure-resistant intermediate container is further sequentially connected with a first needle valve, a first electronic pressure gauge, a gas compressor and a first gas storage steel cylinder through pipelines, and the first gas storage steel cylinder stores the compound gas of carbon dioxide and natural gas; the first pressure-resistant intermediate container is filled with pressurized repeated air and hydraulic oil separated by a first piston, and the second pressure-resistant intermediate container is filled with formation water.

2. The physical simulation apparatus for sequestration of carbon dioxide with water vapor storage of claim 1, wherein a rotation bracket is fixed to the third pressure-resistant intermediate container to rotate the third pressure-resistant intermediate container, and a fixing bracket is fixed to each of the first pressure-resistant intermediate container, the second pressure-resistant intermediate container, and the fourth pressure-resistant intermediate container.

3. The physical simulation apparatus with water vapor storage for carbon dioxide as claimed in claim 1 or 2, wherein the a valve of the six-way valve is connected to a second gas cylinder through a pipe, and nitrogen gas is filled in the second gas cylinder.

4. The simulation method for the repeated gas displacement of saturated water by using the physical simulation device for storing carbon dioxide with a water reservoir as claimed in claim 3, comprising the following steps:

And initial permeability k_i11；

R_k11＝(k_f11-k_i11)/k_i11×100％；

wherein the content of the first and second substances,

5. The simulation method for the displacement of the recompounded gas of saturated water by using the physical simulation device for storing carbon dioxide with water reservoir as claimed in claim 4, wherein the recompounded gas is configured according to the following formula:

V_CO2:V_NG＝(G_o-G_a):G_a

6. The simulation method for repeated gas soaking of saturated water by using the physical simulation device for storing carbon dioxide with water reservoir as claimed in claim 3, comprising the following steps:

And initial permeability k_i12；

Step S7: opening the second needle valve, the third needle valve, the sixth needle valve, the seventh needle valve, the c, d and f valves of the six-way valve and the a and c valves of the three-way valve, starting the first constant-speed and constant-pressure pump, and setting the pressure to be P₀Soaking the experimental core in the repeated distribution of the saturated water for more than 48 hours to ensure that the repeated distribution of the saturated water and the experimental core fully react;

step S8: closing the first constant-speed constant-pressure pump, the second needle valve, the third needle valve, the sixth needle valve and the seventh needle valve, opening the valve b of the six-way valve for pressure relief, closing, and then closing the valves c and f of the six-way valve and the valve c of the three-way valve;

R_k12＝(k_f12-k_i12)/k_i12×100％；

wherein the content of the first and second substances,

7. The method for simulating the repeated gas soaking of saturated water by using the physical simulation device for storing carbon dioxide with water reservoir as claimed in claim 6, wherein the repeated gas is configured according to the following formula:

V_CO2:V_NG＝(G_o-G_a):G_a

8. A simulation method for displacing formation water saturated with carbon dioxide by using the physical simulation device for carbon dioxide sequestration with a water reservoir as claimed in claim 3, comprising the steps of:

And initial permeability k_i21；

R_k21＝(k_f21-k_i21)/k_i21×100％；

wherein the content of the first and second substances,

9. The simulation method for carbon dioxide saturated formation water soaking by using the physical simulation device for carbon dioxide sequestration with water vapor reservoir as claimed in claim 3, comprising the following steps:

And initial permeability k_i22；

Step S7: opening the fourth needle patternThe valve, the eighth needle valve, the c valve, the d valve and the e valve of the six-way valve, a second constant-speed constant-pressure pump is started, and the pressure is set to be P₀Soaking the experimental core in the carbon dioxide saturated formation water for more than 48 hours to ensure that the carbon dioxide saturated formation water and the experimental core fully react;

R_k22＝(k_f22-k_i22)/k_i22×100％；

wherein the content of the first and second substances,