High-temperature and high-pressure carbon dioxide seepage measurement device and experimental method for rock sample

Abstract

The present application belongs to the technical field of carbon dioxide seepage, and particularly relates to a device and method for simulating high-temperature and high-pressure carbon dioxide seepage of rock samples, which comprises a carbon dioxide storage cylinder, a pressure gauge, an on-off valve, a gas inlet, a plug, a pressure-bearing cylinder cover plate, a pressure-bearing cylinder, a hydraulic oil inlet, a core holder, a temperature and pressure sensor, a core holder tail pipe, a tail pipe on-off valve, a hydraulic pump, a hydraulic pump pipeline, a bracket, a computer, a recovery bucket, a heating temperature regulator, a power supply, a power supply socket, a temperature and pressure detection and adjustment device, a cover plate screw through hole, a temperature sensor protrusion, a pressure sensor protrusion, a jack, a pressure-bearing cylinder sealing strip, a sealing screw hole, a pressure-bearing cylinder connecting flange, a holder connecting flange, a connecting hole, a connecting groove, a connecting protrusion, a core holder tail outlet, a pressure-bearing plate, a sealing strip, and a limiting groove. The device and method can simulate the high-temperature and high-pressure environment of the rock and the flow of carbon dioxide in the wellbore encountering rocks of different lithology.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide seepage technology, specifically relating to an experimental device and method for measuring carbon dioxide seepage in various rocks under simulated high temperature and high pressure conditions in strata. Background Technology

[0002] With industrial development, carbon dioxide emissions are enormous, which has a significant impact on the environment. To achieve the "dual carbon" goal, injecting carbon dioxide into the formation for geological storage is an important method for carbon reduction. At the same time, carbon dioxide is an excellent oil displacement agent that can effectively improve the recovery rate of oil and gas fields. Therefore, measuring the permeability of carbon dioxide in formation rocks is very important.

[0003] Traditional carbon dioxide flow measurement devices use rubber sleeves to pressurize rock samples. However, these sleeves have limited strength and low pressure resistance. They cannot withstand high temperatures and are prone to corrosion in a carbon dioxide environment, reducing their strength and failing to simulate real-world high-temperature and high-pressure conditions. Traditional carbon dioxide flow measurement devices can only measure the flow capacity of one type of rock sample at a time. However, when carbon dioxide is injected into the formation through a wellbore, it encounters various lithological reservoirs. Since different lithologies have different flow capacities, this affects the pressure throughout the wellbore, which in turn affects the carbon dioxide flow rate within the rock. This is a coupled relationship that traditional single-sample flow measurement devices cannot simulate.

[0004] Therefore, since traditional devices are unable to simulate the high temperature and high pressure conditions in wells and cannot simulate the situation where carbon dioxide flows into multi-lithological formations in the wellbore, there is an urgent need for an experimental device and method to simulate the carbon dioxide seepage measurement of various rocks under high temperature and high pressure conditions in formations. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide an experimental apparatus and method for measuring carbon dioxide seepage in various rocks under simulated high-temperature and high-pressure conditions in formations. This method solves the problems of existing measurement experimental apparatuses and methods being unable to simulate the high-temperature and high-pressure environment of rocks and the inability to simulate carbon dioxide flowing into multi-lithological rocks in wellbores.

[0006] The technical solution adopted in this invention is as follows: an experimental device for simulating high-temperature and high-pressure carbon dioxide seepage measurement of multi-rock samples. The experimental device includes a carbon dioxide storage cylinder, a pressure gauge, a switch valve, a gas inlet, a plug, a pressure cylinder cover plate, a pressure cylinder, a hydraulic oil inlet, a core holder, a temperature and pressure sensor, a core holder tail pipe, a tail pipe switch valve, a hydraulic pump, hydraulic pump pipelines, a support, a computer, a carbon dioxide recovery tank, a heating temperature regulator, a power supply, a core holder power socket, a temperature and pressure detection and adjustment device, a cover plate screw through hole, a temperature sensor protrusion, a pressure sensor protrusion, a socket, a pressure cylinder sealing strip, a sealing screw hole, a pressure cylinder connecting flange, a core holder connecting flange, a connecting hole, a connecting groove, a connecting protrusion, a core holder tail outlet, a pressure plate, a sealing strip, and a limiting groove. The pressure gauge and switching valve are installed on the outlet pipe of the carbon dioxide storage cylinder. The carbon dioxide storage cylinder is connected to the gas inlet on the pressure cylinder cover plate via a pipeline. The gas inlet of the pressure cylinder cover plate is provided with a pipeline connection thread, and the threaded connection is filled and sealed with PTFE tape to ensure the airtightness of the connection. The pressure cylinder cover plate is provided with cover plate screw through holes, temperature sensor protrusions, pressure sensor protrusions, and insertion holes. The top of the pressure cylinder is provided with sealing screw holes and a pressure cylinder connecting flange. The pressure cylinder cover plate is installed on the pressure cylinder with screws and sealed by the pressure cylinder sealing strip. The plug of the temperature and pressure detection and adjustment device is inserted into the insertion hole. The core holder is a split design, with two parts fastened together by connecting grooves and connecting protrusions, and sealed by the sealing strip in the connecting groove. The core holder is sealed, with two separate parts fixed by bolts passing through the connecting holes. One end of the core holder has a core holder connecting flange, and the other end has a core holder tail outlet. The core holder is mounted on the pressure cylinder through the flange. There are at least four core holders. After the core holder tail outlet and the core holder tail pipe are connected, they are connected to the carbon dioxide recovery tank through a pipeline equipped with a tail pipe switch valve. The temperature and pressure sensor is installed on the core holder tail pipe and is electrically connected to the computer through a wire. The hydraulic oil inlet on the core holder is connected to the hydraulic pump through a hydraulic pump pipeline. The power supply is electrically connected to the heating temperature regulator through a wire. The heating temperature regulator is connected to the power socket of the core holder through a wire to supply power to the heating wire on the inner wall of the core holder.

[0007] Furthermore, the core holder is equipped with a pressure plate and a limiting groove on its separate parts.

[0008] Furthermore, the flange connection between the pressure cylinder and the core holder is sealed with sealing packing.

[0009] Furthermore, the core holder is placed on a support.

[0010] Furthermore, the pipelines between the containers are connected by pressure-bearing steel pipes, the joints are connected by threads and sealed, and the electrical components are connected by cables to supply power or transmit signals.

[0011] Furthermore, the hydraulic pump is a general-purpose hydraulic pump with a pressurization capacity of not less than 100MPa and a pressure holding function. It is connected to a special hydraulic connector on the clamp via a hose and uses a threaded connection.

[0012] Furthermore, the carbon dioxide recovery bottle is a common carbon dioxide recovery bottle, which can effectively collect residual carbon dioxide gas, prevent leakage, and allow the carbon dioxide gas to be reused.

[0013] Furthermore, the support is a metal support used to support the core holder.

[0014] Furthermore, the pressure cylinder cover plate is a metal cover plate with an inner layer of resistance wires for heating and an outer stepped shape. The upper part of the cover plate has an interface for connecting to a carbon dioxide cylinder, the upper part has an interface for connecting to a temperature and pressure controller, and the lower part has temperature and pressure sensors for monitoring temperature and pressure.

[0015] Furthermore, the pressure cylinder is a metal cylindrical cylinder with a threaded hole at the top that connects to the pressure cylinder cover plate via threads. A sealing ring is present at the contact point between the pressure cylinder and the pressure cylinder cover plate to ensure no air leakage. The pressure cylinder has an opening on its side, with a flange for connection to the core holder. A sealing ring is present at the connection point, and the connection is secured with bolts.

[0016] Furthermore, the experimental method for simulating high-temperature and high-pressure carbon dioxide seepage measurement experiments on multi-rock samples using experimental apparatus includes the following steps: Step 1: Grind the cylindrical rock core specimens to be tested according to the experimental requirements. After placing the four cylindrical rock core specimens into the cavities of the four separate rock core holders, snap the separate rock core holders together to form a single rock core holder. Step 2: After the core specimen is installed, check whether the assembly and connection of the entire experimental device are correct and secure, and whether the airtightness of each part is intact. Ensure that the connection is correct and secure and the airtightness is intact. After the inspection is completed, turn on the hydraulic pump and adjust the pump pressure to a suitable pressure according to the requirements of the experimental plan. Apply confining pressure to the core in the core holder, turn on the power, and adjust the temperature to the temperature required for the experiment through the heating temperature regulator. Heat and wait for the temperature to stabilize. Step 3: Open the tailpipe switch valve and the carbon dioxide cylinder switch valve to allow carbon dioxide to flow into the pressure cylinder at a constant rate. Observe the temperature and pressure changes through the temperature and pressure detection and control device, and adjust the knob on the temperature and pressure detection and control device in a timely manner to adjust the temperature, ensure that the carbon dioxide is in a supercritical state, and record the pressure value. Step 4: After the flow rate and pressure detected at the tail of the core holder remain constant, start collecting data, performing calculations and processing via computer. Step 5: After completing the experiment, first close the switch valve on the carbon dioxide cylinder, then turn off the hydraulic pump and perform a pressure relief operation. Keep the switch valve on the tail pipe of the core holder open. After the pressure in the pressure cylinder drops to a safe pressure, close the tail pipe switch valve, remove the carbon dioxide recovery tank, and perform harmless treatment on the substances in the recovery tank. Disassemble all parts of the pipeline and wires, put all parts of the components back in their proper positions, and the experiment is over.

[0017] Furthermore, the pressure regulating and detection device can detect the temperature and pressure in the pressure cylinder, and adjust the heating power of the resistance wire on the inner wall of the pressure cylinder according to the displayed temperature, so that the carbon dioxide enters the pressure cylinder in a supercritical state.

[0018] The beneficial effects of this invention are as follows: It provides an experimental apparatus and method for measuring carbon dioxide seepage in various rocks under simulated high-temperature and high-pressure conditions in formations, solving the problems of existing measurement experimental apparatuses and methods that cannot simulate the high-temperature and high-pressure environment of rocks and the encounter of carbon dioxide with various rock types in the wellbore. Its main advantages are as follows: 1) The experimental setup can apply high confining pressure to the core and can also be heated to simulate the characteristics of high temperature and high pressure in the formation, making the experimental environment closer to the actual formation conditions, making the field application of the experiment more accurate, and adding two adjustable parameters, temperature and pressure, which increases the number of variable parameters and broadens the research content. 2) The experimental device uses hydraulic pressure and metal pressure plates for pressure transmission, which enables the device to apply higher pressure, simulate the high pressure characteristics of the formation, and is safer and less prone to failure. 3) The experimental setup can simulate an actual wellbore and adjust the temperature to make carbon dioxide be in a supercritical state, and can also simulate the distribution of carbon dioxide in the wellbore. 4) The experimental setup can conduct seepage experiments on core samples with multiple physical parameters simultaneously, simulating the characteristics of multiple parameters of actual strata rocks. The experimental environment is closer to reality, the measured data is more accurate, and the field applicability is stronger. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the experimental apparatus in Example 1; Figure 2 This is a three-dimensional structural diagram of the pressure-bearing cylinder head plate in Embodiment 1; Figure 3 This is a three-dimensional structural diagram of the pressure cylinder before assembly in Example 1; Figure 4 This is a three-dimensional structural diagram of the core holder in Example 1; Figure 5 This is a schematic diagram of the split structure of the core holder in Example 1. Detailed Implementation

[0020] Example

[0021] Referring to the figures, an experimental apparatus for simulating carbon dioxide seepage measurement in multi-rock samples under high temperature and pressure includes a carbon dioxide storage cylinder 1, a pressure gauge 2, a switching valve 3, a gas inlet 4, a plug 5, a pressure cylinder cover plate 6, a pressure cylinder 7, a hydraulic oil inlet 8, a core holder 9, a temperature and pressure sensor 10, a core holder tailpipe 11, a tailpipe switching valve 12, a hydraulic pump 13, a hydraulic pump pipeline 14, a support 15, a computer 16, a carbon dioxide recovery tank 17, and a heating temperature regulator. 18. Regulator; 19. Power supply; 20. Core holder power socket; 21. Temperature and pressure detection and adjustment device; 22. Cover plate screw through hole; 23. Temperature sensor protrusion; 24. Pressure sensor protrusion; 25. Socket; 26. Pressure cylinder sealing strip; 27. Sealing screw hole; 28. Pressure cylinder connecting flange; 29. ​​Core holder connecting flange; 30. Connecting hole; 31. Connecting groove; 32. Connecting protrusion; 33. Core holder tail outlet; 34. Pressure plate; 35. Sealing strip; 36. Limiting groove. The pressure gauge and switching valve are installed on the outlet pipe of the carbon dioxide storage cylinder. The carbon dioxide storage cylinder is connected to the gas inlet on the pressure cylinder cover plate via a pipeline. The gas inlet of the pressure cylinder cover plate is provided with a pipeline connection thread, and the threaded connection is filled and sealed with PTFE tape to ensure the airtightness of the connection. The pressure cylinder cover plate is provided with cover plate screw through holes, temperature sensor protrusions, pressure sensor protrusions, and insertion holes. The top of the pressure cylinder is provided with sealing screw holes and a pressure cylinder connecting flange. The pressure cylinder cover plate is installed on the pressure cylinder with screws and sealed by the pressure cylinder sealing strip. The plug of the temperature and pressure detection and adjustment device is inserted into the insertion hole. The core holder is a split design, with two parts fastened together by connecting grooves and connecting protrusions, and sealed by the sealing strip in the connecting groove. The core holder is sealed, with two separate parts fixed by bolts passing through the connecting holes. One end of the core holder has a core holder connecting flange, and the other end has a core holder tail outlet. The core holder is mounted on the pressure cylinder through the flange. There are at least four core holders. After the core holder tail outlet and the core holder tail pipe are connected, they are connected to the carbon dioxide recovery tank through a pipeline equipped with a tail pipe switch valve. The temperature and pressure sensor is installed on the core holder tail pipe and is electrically connected to the computer through a wire. The hydraulic oil inlet on the core holder is connected to the hydraulic pump through a hydraulic pump pipeline. The power supply is electrically connected to the heating temperature regulator through a wire. The heating temperature regulator is connected to the power socket of the core holder through a wire to supply power to the heating wire on the inner wall of the core holder.

[0022] The core holder is equipped with a pressure plate and a limiting groove on its separate parts; the flange connection between the pressure cylinder and the core holder is sealed with sealing packing; the core holder is placed on a support.

[0023] The core holder is used to hold the core block and apply pressure to the cylindrical lithological block. The core holder is divided into two parts. One part has a sealing groove with sealing filler inside, and the other part has a sealing protrusion. After the core is placed in the cavity, the two parts cooperate with each other and are fixed with bolts to make the two parts into a whole. The whole is installed on the pressure cylinder and fixed with bolts. Each part of the core holder has a heating wire on the inner wall for heating, and a power socket on the outer wall. Each unit is equipped with a semi-tubular pressure plate with a limiting groove. The pressure plate and the inner wall of the core holder form a closed cavity, which is filled with hydraulic oil. The outer wall of the core holder has a hole communicating with the inner wall, and threaded protrusions connect to the hydraulic pump line. This pressurizes the closed cavity formed by the pressure plate and the inner wall of the core holder. After pressurization, the pressure plate presses against the cylindrical core block inside, and the hydraulic pressure applied to the pressure plate is transmitted to the core, creating confining pressure. One end of the unit has a hole for carbon dioxide discharge and pressure and flow rate measurement.

[0024] The experimental method for simulating high-temperature and high-pressure carbon dioxide seepage measurement in multi-rock samples using experimental apparatus includes the following steps: Step 1: Grind the cylindrical core specimens to be tested according to the experimental requirements. After placing the four cylindrical core specimens into the cavities of the four separate core holders, snap the separate core holders together to assemble them into a single core holder. Step 2: After the core specimen is installed, check whether the assembly and connection of the entire experimental device are correct and secure, and whether the airtightness of each part is intact. Ensure that the connection is correct and secure and the airtightness is intact. After the inspection is completed, turn on the hydraulic pump and adjust the pump pressure to a suitable pressure according to the requirements of the experimental plan. Apply confining pressure to the core in the core holder, turn on the power, and adjust the temperature to the temperature required for the experiment through the heating temperature regulator. Heat and wait for the temperature to stabilize. Step 3: Open the tailpipe switch valve and the carbon dioxide cylinder switch valve to allow carbon dioxide to flow into the pressure cylinder at a constant rate. Observe the temperature and pressure changes through the temperature and pressure detection and control device, and adjust the knob on the temperature and pressure detection and control device in a timely manner to adjust the temperature, ensure that the carbon dioxide is in a supercritical state, and record the pressure value. Step 4: After the flow rate and pressure detected at the tail of the core holder remain constant, start collecting data, performing calculations and processing via computer. Step 5: After completing the experiment, first close the switch valve on the carbon dioxide cylinder, then turn off the hydraulic pump and perform a pressure relief operation. Keep the switch valve on the tail pipe of the core holder open. After the pressure in the pressure cylinder drops to a safe pressure, close the tail pipe switch valve, remove the carbon dioxide recovery tank, and perform harmless treatment on the substances in the recovery tank. Disassemble all parts of the pipeline and wires, put all parts of the components back in their proper positions, and the experiment is over.

Claims

1. An experimental apparatus for simulating carbon dioxide seepage measurement in multi-rock samples under high temperature and pressure, characterized in that: The experimental setup includes a carbon dioxide storage cylinder, pressure gauge, switch valve, gas inlet, plug, pressure cylinder cover plate, pressure cylinder, hydraulic oil inlet, core holder, temperature and pressure sensor, core holder tailpipe, tailpipe switch valve, hydraulic pump, hydraulic pump pipeline, support frame, computer, carbon dioxide recovery tank, heating temperature regulator, power supply, core holder power socket, temperature and pressure detection and adjustment device, cover plate screw through hole, temperature sensor protrusion, pressure sensor protrusion, socket, pressure cylinder sealing strip, sealing screw hole, pressure cylinder connecting flange, core holder connecting flange, connecting hole, connecting groove, connecting protrusion, core holder tail outlet, pressure plate, sealing strip, and limit groove. The pressure gauge and switching valve are installed on the outlet pipe of the carbon dioxide storage cylinder. The carbon dioxide storage cylinder is connected to the gas inlet on the pressure cylinder cover plate via a pipeline. The pressure cylinder cover plate has a cover plate screw through hole, a temperature sensor protrusion, a pressure sensor protrusion, and a socket. The top of the pressure cylinder has a sealing screw hole and a pressure cylinder connecting flange. The pressure cylinder cover plate is installed on the pressure cylinder with screws and sealed by the pressure cylinder sealing strip. The plug of the temperature and pressure detection and adjustment device is inserted into the socket. The core holder is a split design. The two parts are fastened together by a connecting groove and a connecting protrusion and sealed by a sealing strip in the connecting groove. The two parts are connected by screws passing through the connecting hole. The core holder is fixed in place by bolts. One end of the core holder has a connecting flange, and the other end has a tail outlet. The core holder is mounted on the pressure cylinder via the flange. There are at least four core holders. After the tail outlet of the core holder is connected to the tail pipe of the core holder, it is connected to the carbon dioxide recovery tank through a pipeline equipped with a tail pipe switch valve. The temperature and pressure sensor is installed on the tail pipe of the core holder and is electrically connected to the computer via a wire. The hydraulic oil inlet on the core holder is connected to the hydraulic pump via a hydraulic pump pipeline. The power supply is electrically connected to the heating temperature regulator via a wire, and the heating temperature regulator is connected to the power socket of the core holder via a wire.

2. The experimental apparatus for simulating high-temperature pressure multi-rock sample carbon dioxide seepage measurement according to claim 1, characterized in that: The core holder is equipped with a pressure plate and a limiting groove on its separate parts.

3. The experimental apparatus for simulating high-temperature pressure multi-rock sample carbon dioxide seepage measurement according to claim 1, characterized in that: The flange connection between the pressure cylinder and the core holder is sealed with sealing packing.

4. The experimental apparatus for simulating high-temperature and high-pressure multi-rock sample carbon dioxide seepage measurement according to claim 1, characterized in that: The core holder is placed on the support.

5. The experimental apparatus for simulating high-temperature pressure multi-rock sample carbon dioxide seepage measurement according to any one of claims 1-4, characterized in that: The experimental method for simulating high-temperature and high-pressure carbon dioxide seepage measurement in multi-rock samples using experimental apparatus includes the following steps: Step 1: Grind the cylindrical rock core specimens to be tested according to the experimental requirements. After placing the four cylindrical rock core specimens into the cavities of the four separate rock core holders, snap the separate rock core holders together to form a single rock core holder. Step 2: After the core specimen is installed, check whether the assembly and connection of the entire experimental device are correct and secure, and whether the airtightness of each part is intact. Ensure that the connection is correct and secure and the airtightness is intact. After the inspection is completed, turn on the hydraulic pump and adjust the pump pressure to a suitable pressure according to the requirements of the experimental plan. Apply confining pressure to the core in the core holder, turn on the power, and adjust the temperature to the temperature required for the experiment through the heating temperature regulator. Heat and wait for the temperature to stabilize. Step 3: Open the tailpipe switch valve and the carbon dioxide cylinder switch valve to allow carbon dioxide to flow into the pressure cylinder at a constant rate. Observe the temperature and pressure changes through the temperature and pressure detection and adjustment device, and adjust the knob on the temperature and pressure detection and adjustment device in a timely manner to adjust the temperature, ensure that the carbon dioxide is in a supercritical state, and record the pressure value. Step 4: After the flow rate and pressure detected at the tail of the core holder remain constant, start collecting data, performing calculations and processing via computer. Step 5: After completing the experiment, first close the switch valve on the carbon dioxide cylinder, then turn off the hydraulic pump and perform a pressure relief operation. Keep the switch valve on the tail pipe of the core holder open. After the pressure in the pressure cylinder drops to a safe pressure, close the tail pipe switch valve, remove the carbon dioxide recovery tank, and perform harmless treatment on the substances in the recovery tank. Disassemble all parts of the pipeline and wires, put all parts of the components back in their proper positions, and the experiment is over.

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