Experimental device for liquid CO2 cooling fracturing propping agent

Abstract

The utility model relates to an experimental device for cooling a fracturing propping agent by using liquid CO2. The experimental device comprises a plunger pump, a CO2 Dewar tank, a cooling device, a valve I, a valve II and a valve III, the cooling device comprises a fixed seat and a pressure container arranged on the fixed seat, a fixed rod is arranged on the pressure container, a lower cover is arranged at the bottom of the pressure container, and a screwed plug is arranged at the bottom of the lower cover; ten temperature sensor interfaces are arranged on the two sides of the pressure container and used for installing a temperature sensor I and a temperature sensor II. An upper cover is arranged at the upper end of the pressure container, and a safety valve, an exhaust valve, a pressure sensor and a gaseous CO2 inlet are arranged at the top of the upper cover; two sides of the lower end of the pressure container are provided with two liquid CO2 inlets, and one liquid CO2 inlet is screwed with a screwed plug II. The device can simulate the process of cooling the fracturing propping agent by the CO2 closed sand mulling equipment indoors, effectively guides the development and design of the CO2 closed sand mulling equipment, further provides core equipment for CO2 pure dry fracturing, and promotes the development of the CCUS technology.

Description

Technical Field

[0001] This field relates to the oil and gas extraction sector, particularly the combination of reservoir fracturing and CCUS, specifically an experimental device for liquid CO2-cooled fracturing proppant. Background Technology

[0002] Effective development of unconventional oil and gas resources, such as low-permeability, tight oil and gas, and shale oil and gas, is crucial for ensuring my country's energy security. Fracturing technology is a primary measure for reservoir stimulation to enhance the production of unconventional oil and gas resources, and with the development of CCUS technology, CO2 fracturing technology has entered a new stage of development.

[0003] CO2 fracturing is divided into hybrid fracturing and pure dry fracturing, depending on the ratio of water to CO2. Hybrid fracturing technology is relatively mature, and most of its key equipment is also traditional, unconventional hydraulic fracturing equipment. In contrast, the development of pure dry CO2 fracturing technology is still in its early stages, and its equipment is relatively specialized. Existing core equipment, the closed-loop sand mixing equipment, is difficult to meet the requirements of large-scale construction, and its development is constrained by certain technical bottlenecks.

[0004] The large-scale application of CO2 dry fracturing requires that the closed CO2 mixing equipment can continuously supply the required CO2 fracturing fluid to the fracturing equipment under pressure.

[0005] Due to the unique physical properties of CO2, it remains liquid only under certain temperature and pressure conditions. If high-temperature fracturing proppant is mixed with low-temperature liquid CO2, the liquid CO2 will vaporize, leading to cavitation and other phenomena in the fracturing pump, causing damage. Therefore, the development of a closed CO2 proppant mixing device first requires solving the cooling problem of the fracturing proppant. Liquid CO2 should be used to pre-cool the fracturing proppant so that its temperature reaches equilibrium with that of the liquid CO2.

[0006] Liquid CO2 precooled fracturing proppant is a relatively complex issue involving phase change, and there is currently little relevant research, which greatly hinders the development of a closed CO2 sand mixing device suitable for large-scale pure dry CO2 fracturing. Utility Model Content

[0007] Therefore, in order to solve the above-mentioned technical problems, this utility model proposes an experimental device for liquid CO2 cooling fracturing proppant, which realizes indoor experimental simulation of liquid CO2 cooling fracturing proppant, and can effectively guide the design and development of CO2 closed sand mixing equipment that meets the needs of large-scale application.

[0008] To achieve the above objectives, this utility model also provides the working process of the above-mentioned experimental apparatus for liquid CO2 cooling fracturing proppant.

[0009] The technical solution adopted by this utility model is as follows:

[0010] An experimental apparatus for cooling fracturing proppant with liquid CO2 includes a plunger pump, a CO2 Dewar flask, a cooling device, valve I, valve II, and valve III. The cooling device includes: a mounting base for mounting a pressure vessel, with a fixing rod on the pressure vessel for securing it to the base. The pressure vessel has a bottom cover with a plug at its bottom. Several temperature sensor interfaces are located on both sides of the pressure vessel for mounting temperature sensor I and temperature sensor II. An upper cover is located at the top of the pressure vessel, with a safety valve, an exhaust valve, a pressure sensor, and a gaseous CO2 inlet on its top. Two liquid CO2 inlets are located on both sides of the lower end of the pressure vessel, one of which is plugged with plug II.

[0011] Preferably, the pressure vessel is a heat-insulated pressure vessel.

[0012] Preferably, the temperature sensor I and temperature sensor II have different lengths, and can measure the temperature at the center and the edge.

[0013] The beneficial effects of this utility model are as follows:

[0014] This invention relates to an experimental apparatus for cooling fracturing proppant with liquid CO2, which can be used to study the cooling effect of liquid CO2 on fracturing proppant.

[0015] This invention provides an experimental device for cooling fracturing proppant with liquid CO2, which can simulate the effect of using liquid CO2 to cool proppant in a closed sand mixing equipment.

[0016] The workflow of this utility model for an experimental device for liquid CO2-cooled fracturing proppant can simulate the workflow of a closed sand mixing device.

[0017] This invention relates to an experimental device for cooling fracturing proppant with liquid CO2, which can simulate the process of cooling fracturing proppant in a closed CO2 mixing equipment indoors. It can effectively guide the development and design of closed CO2 mixing equipment, further provide core equipment for CO2 dry fracturing, promote the development of CCUS technology, and thus bring considerable economic benefits. Attached Figure Description

[0018] Figure 1 This is a schematic diagram (I) of the experimental apparatus for liquid CO2-cooled fracturing proppant according to this utility model.

[0019] Figure 2 This is a schematic diagram (II) of the experimental apparatus for liquid CO2-cooled fracturing proppant according to this utility model.

[0020] Figure 3This is a three-dimensional structural diagram of the experimental apparatus for liquid CO2-cooled fracturing proppant according to this utility model;

[0021] Figure 4 This is a schematic diagram showing the connection relationship of the entire experimental apparatus of this utility model;

[0022] Wherein: 1-fixed seat, 2-plug I, 3-lower cover, 4-temperature sensor interface, 5-temperature sensor I, 6-fixed rod, 7-temperature sensor II, 8-pressure vessel, 9-upper cover, 10-safety valve, 11-exhaust valve, 12-pressure sensor, 13-liquid CO2 inlet, 14-gaseous CO2 inlet, 15-plug II, 16-plunger pump, 17-valve I, 18-CO2 dewar, 19-valve II, 20-cooling device, 21-valve III. Detailed Implementation

[0023] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0024] Example 1:

[0025] like Figures 1 to 4 As shown, this embodiment provides an experimental device for cooling fracturing proppant with liquid CO2. The device mainly includes a plunger pump (16), a CO2 Dewar jar (18), a cooling device (20), valve I (17), valve II (19), and valve III (21). The cooling device (20) includes a mounting base (1) for installation. A heat-insulated pressure vessel (8) is installed on the mounting base (1). A fixing rod (6) is provided on the pressure vessel (8) for fixing the pressure vessel (8) on the mounting base (1). The pressure vessel (8) has a bottom cover (3) at the bottom, and a plug I (2) is provided at the bottom of the bottom cover (3); the pressure vessel (8) has 5 temperature sensor interfaces (4) symmetrically arranged on both sides along the height direction, which are used to install temperature sensor I (5) and temperature sensor II (7). Temperature sensor I (5) and temperature sensor II (7) have different lengths and can measure the temperature of the center and the edge; the pressure vessel (8) has a top cover (9) at the top, and a safety valve (10), an exhaust valve (11), a pressure sensor (12), and a gaseous CO2 inlet (14) are provided on the top of the top cover (9); the pressure vessel (8) has two liquid CO2 inlets (13) on both sides at the bottom, one of which is screwed with a plug II (15).

[0026] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, based on the technical teachings provided by this utility model and as common knowledge in the field, other equivalent modifications and improvements can be made, which should also be considered within the scope of protection of this utility model.

Claims

1. A device for cooling proppant in liquid CO2 comprising a plunger pump, a CO2 dewar, a cooling device, valve I, valve II, valve III, characterized in that, The cooling device comprises a fixing seat for installation, a pressure container is installed on the fixing seat, a fixing rod is arranged on the pressure container and used for fixing the pressure container on the fixing seat, a lower cover is arranged at the bottom of the pressure container, a plug is arranged at the bottom of the lower cover, a plurality of temperature sensor interfaces are arranged on both sides of the pressure container and used for installing temperature sensor I and temperature sensor II, an upper cover is arranged at the upper end of the pressure container, a safety valve, an exhaust valve, a pressure sensor and a gaseous CO2 inlet are arranged at the top of the upper cover, and two liquid CO2 inlets are arranged at the lower end of the pressure container, and a plug II is screwed on one of the two liquid CO2 inlets.

2. The experimental apparatus for cooling of proppant by liquid CO2 of claim 1, wherein, The pressure container is a heat-insulating type pressure container.

3. The experimental apparatus for cooling of proppant by liquid CO2 of claim 1, wherein, The temperature sensor I and the temperature sensor II are different in length and are used for measuring the temperatures of the center and the edge respectively.

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