CN111271041A

CN111271041A - Normal pressure type carbon dioxide fracturing ground sand mixing device

Info

Publication number: CN111271041A
Application number: CN202010064988.3A
Authority: CN
Inventors: 朱端银; 徐建宁; 李万钟; 刘豪
Original assignee: Xian Shiyou University
Current assignee: Xian Shiyou University
Priority date: 2020-01-20
Filing date: 2020-01-20
Publication date: 2020-06-12

Abstract

A normal pressure type carbon dioxide fracturing ground sand mixing device comprises a carbon dioxide storage tank, wherein the output end of the carbon dioxide storage tank is respectively connected with the input ends of a sand feeding liquid pipeline and a sand mixer liquid pipeline through a power pump; the output end of the sand mixer liquid inlet pipeline is connected with the input end of the sand mixer, and a third stop valve is arranged on the sand mixer liquid inlet pipeline. The invention has the characteristics of continuous sand adding fracturing operation, real-time control of sand concentration, simple equipment disassembly and assembly and control, low failure rate, easy maintenance, high economic benefit and the like.

Description

Normal pressure type carbon dioxide fracturing ground sand mixing device

Technical Field

The invention relates to the technical field of petroleum and natural gas industry, in particular to a normal-pressure carbon dioxide fracturing ground sand mixing device.

Background

The research and development of unconventional oil and gas resource exploration and development technologies, the research and development of various new production processes and new equipment become problems which are urgently needed to be solved by current petroleum machinery equipment researchers, and fracturing is widely applied to oil and gas well production increasing operation as a reservoir permeability increasing technology. In equipment used in fracturing operation, a fracturing sand mixing device is one of the most important devices, plays a vital role in the fracturing process of an oil field, and is the key for completing fracturing construction and obtaining a good fracturing effect. The ground sand mixing truck sand mixing technology is widely applied to actual production operation of various large oil fields as the most common reservoir permeability-increasing technology at present. The ground sand mixing truck sand mixing technology is that fracturing fluid (usually liquid carbon dioxide) and propping agent (usually quartz sand) are mixed in a vehicle-mounted mixing tank and then injected into the bottom of a well by a high-pressure pump to perform fracturing operation. In actual operation, after the mixture in the mixing tank is used up, the operation needs to be stopped, and the fracturing fluid and the propping agent are injected into the mixing tank again to be mixed so as to continue the sand fracturing operation. Therefore, continuous sand adding fracturing operation cannot be realized, and the sand adding fracturing efficiency is seriously influenced. In addition, the sand mixing technology of the ground sand mixing truck has the defects of incapability of controlling the concentration of fracturing sand in real time, easily causing inaccurate sand ratio of injected stratum, complex equipment control, high failure rate and the like.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a normal-pressure type carbon dioxide fracturing ground sand mixing device which has the characteristics of continuous sand adding and fracturing operation, real-time control of sand concentration, simplicity in equipment disassembly and assembly and control, low failure rate, easiness in maintenance, high economic benefit and the like.

In order to achieve the purpose, the invention adopts the technical scheme that:

a normal pressure type carbon dioxide fracturing ground sand mixing device comprises a carbon dioxide storage tank 1, wherein the output end of the carbon dioxide storage tank 1 is respectively connected with the input ends of a sand feeding liquid pipeline 13 and a sand mixer liquid pipeline 14 through a power pump 2, the output end of the sand feeding liquid pipeline 13 is communicated with a sand feeding pipeline, the output end of the sand feeding pipeline is connected to a sand mixer 10 through a first sand conveying pipe 16 and a second sand conveying pipe 17, and the output end of the sand mixer 10 is connected with a fracturing pump 11 through a high-pressure pipeline 18 and enters a wellhead device 12; the output end of the sand mixer liquid inlet pipeline 14 is connected with the input end of the sand mixer 10, and the sand mixer liquid inlet pipeline 14 is provided with a third stop valve 19.

The sand adding pipeline is sequentially provided with a flow regulating valve 3, a pressure reducing valve 4, a first stop valve 5, a sand box 6, a one-way valve 8, a second stop valve 9 and a closed box cover 7 positioned on the sand box 6 from left to right.

The sand mixer 10 comprises a nozzle 10-1, a mixing chamber 10-2, a throat 10-3 and a diffusion pipe 10-4 respectively, a sand mixer liquid inlet pipeline 14 is connected with the nozzle 10-1, and a second sand conveying pipe 17 is connected with the mixing chamber 10-2.

The sand adding pipeline is at least divided into two paths.

The invention has the beneficial effects that:

the invention has the biggest characteristics that the continuous sand adding fracturing operation can be realized, the major defect that sand mixing needs to be stopped in the sand mixing process of the traditional sand mixer is thoroughly changed, and the sand adding fracturing operation efficiency is greatly improved;

the purposes of sand adding operation under normal pressure and controlling the sand-liquid ratio in real time are realized;

each part of the device is in a modular design, so that the device is convenient to disassemble, assemble and replace;

the fracturing sand mixing truck can replace a sand mixing truck in the traditional fracturing sand mixing process, and the economy of fracturing sand mixing is greatly improved.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, a normal pressure type carbon dioxide fracturing ground sand mixing device comprises the following components: carbon dioxide storage tank 1, power pump 2, parallelly connected multiunit of setting adds sand pipeline (this legend lists three groups but not only limits to three groups, include respectively adding sand pipeline I, add sand pipeline II, add sand pipeline III, every group adds sand pipeline all contains the same inter block spare, from left to right set gradually flow control valve 3, relief valve 4, first stop valve 5, sand box 6, be located the airtight case lid 7 on sand box 6, check valve 8, second stop valve 9), sand mixer 10, booster pump 11, wellhead assembly 12, add sand inlet pipeline 13, sand mixer inlet pipeline 14, divide liquid pipeline 15, first sand conveying pipe 16, second sand conveying pipe 17, high-pressure pipeline 18, third stop valve 19. The sand mixer 10 comprises a nozzle 10-1, a mixing chamber 10-2, a throat 10-3, a diffusion pipe 10-4 and the like, and the fracturing fluid and the proppant are mixed in the sand mixer 10 by means of a jet flow principle.

The working principle of the invention is as follows:

as shown in fig. 1: in actual work, liquid carbon dioxide in the carbon dioxide storage tank 1 is respectively conveyed to the sand feeding liquid inlet pipeline 13 and the sand mixer liquid inlet pipeline 14 through the power pump 2, and the liquid carbon dioxide enters the nozzle 10-1 through the sand mixer liquid inlet pipeline 14 and the third stop valve 19. The liquid carbon dioxide entering the sand feeding liquid inlet pipeline 13 respectively enters the sand feeding pipeline I, the sand feeding pipeline II, the sand feeding pipeline III and the like through the liquid separating pipeline 15, a certain pressure environment is created in the sand box 6, the propping agent in the sand box 6 is driven to enter the mixing chamber 10-2 along the first sand conveying pipe 16 and the second sand conveying pipe 17 in sequence to be mixed with the high-speed liquid carbon dioxide passing through the nozzle 10-1 in the mixing chamber 10-2, and the mixture enters the fracturing pump 11 through the high-pressure pipeline 18 after being pressurized through the throat pipe 10-3 and the diffusion pipe 10-4 to be pressurized again and then enters the wellhead device 12 so as to realize sand feeding fracturing operation. In actual operation, the sand box in each sand adding pipeline is filled, the stop valve in the sand adding pipeline I is opened to conduct the pipeline, and the stop valves in the rest sand adding pipelines are closed to cut off the passage. Along with adding sand fracturing operation and going on, the proppant in the sand box of sand adding pipeline I reduces gradually, opens the stop valve in the sand adding pipeline II when the proppant in the sand box of sand adding pipeline I is about to exhaust to adjust flow valve, the air-vent valve etc. in the sand adding pipeline II to suitable numerical value, in order to switch on sand adding pipeline II and system UNICOM. And then closing a stop valve in the sand adding pipeline I, adjusting a pressure regulating valve in the sand adding pipeline I to a normal pressure value, and opening a closed box cover on the sand box to add the proppant. The operation is carried out on other sand adding pipelines in sequence, so that continuous sand adding fracturing operation without stopping can be realized, and in addition, two or more sand adding pipelines can be simultaneously conducted in actual operation so as to carry out large-discharge sand adding fracturing operation.

Claims

1. The normal-pressure type carbon dioxide fracturing ground sand mixing device is characterized by comprising a carbon dioxide storage tank (1), wherein the output end of the carbon dioxide storage tank (1) is respectively connected with the input ends of a sand feeding liquid pipeline (13) and a sand mixer liquid pipeline (14) through a power pump (2), the output end of the sand feeding liquid pipeline (13) is communicated with a sand feeding pipeline, the output end of the sand feeding pipeline is connected to a sand mixer (10) through a first sand conveying pipe (16) and a second sand conveying pipe (17), and the output end of the sand mixer (10) is connected with a fracturing pump (11) through a high-pressure pipeline (18) and enters a wellhead device (12); the output end of the sand mixer liquid inlet pipeline (14) is connected with the input end of the sand mixer (10), and a third stop valve (19) is arranged on the sand mixer liquid inlet pipeline (14).

2. The normal pressure type carbon dioxide fracturing ground sand mixing device according to claim 1, wherein the sand adding pipeline is provided with a flow regulating valve (3), a pressure reducing valve (4), a first stop valve (5), a sand box (6), a one-way valve (8), a second stop valve (9) and a closed box cover (7) on the sand box (6) in sequence from left to right.

3. A normal pressure type carbon dioxide fracturing ground sand mixing device according to claim 1, wherein the sand mixer (10) comprises a nozzle (10-1), a mixing chamber (10-2), a throat (10-3) and a diffuser (10-4), the sand mixer inlet line (14) is connected with the nozzle (10-1), and the second sand conveying pipe (17) is connected with the mixing chamber (10-2).

4. The normal pressure type carbon dioxide fracturing surface sand mixing device according to claim 1, wherein the sand adding pipeline is at least two-way.