A pulse sand fracturing system and its control method

Abstract

The invention provides an impulse type sand fracturing system and a control method thereof. The impulse type sand fracturing system comprises a sand hopper arranged on a fracturing blender truck, a fracturing liquid tank, a sand-liquid mixing cylinder and a fracturing pump car group. A supporting agent circulation loop is connected in parallel to a pipeline between the sand hopper and the sand-liquid mixing cylinder. A flow-direction converting device is arranged at the front end of the supporting agent circulation loop. The tail end of the supporting agent circulation loop is connected with the sand hopper. The impulse type sand fracturing system further comprises a control device which comprises a user input-output end, a PLC, a flow direction converting driver, a circulation feedback driver and a linkage butterfly valve driver. An existing conventional fracturing blender truck is used as a foundation platform, supporting agent double-way feeding control, supporting agent circulation control and fracturing liquid and sand carrying liquid impulse adding control are integrated, seamless connecting with an existing sand tank, the fracturing blender truck, the fracturing pump car group and a liquid tank group can be achieved, impulse type injection of fracturing liquid and sand carrying liquid is achieved, sand cluster type supporting of supporting agents in a crack is achieved, and the flow conductivity of the crack is improved.

Description

technical field [0001] The patent of the present invention relates to the field of oil and gas field development, specifically a high-efficiency and low-cost hydraulic pulse type sanding fracturing system and its control method. Background technique [0002] The main goal of the hydraulic fracturing process is to form a certain length of artificial fractures with high conductivity in the formation, so as to reduce the oil and gas flow resistance of the oil and gas reservoir and achieve the purpose of increasing production. The conventional hydraulic fracturing technology adopts the construction method of continuously adding sand, so that the proppant is continuously and evenly laid in the artificial fracture. The artificial fracture formed in this way is through the pores between the spherical proppant as the channel for oil and gas seepage. Fracturing fluid residues and broken proppant particles will block the pores of the proppant, thereby reducing the conductivity of frac...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the performance conditions of the existing fracturing equipment, there is a large index gap between the domestic pulsed sanding process and the foreign process

Foreign companies have specially designed sand mixing vehicles with complex structures and proprietary technology protection to implement high-pulse frequency sand fracturing. The minimum interval between the sand-carrying liquid section and the pure liquid section can reach 10 seconds, which can effectively ensure proppant dispersion. With the formation of artificial fracture support plungers, due to the lack of similar equipment in China, the existing sand mixer can only be used to start and stop the sand mixer to carry out approximate pulse sand fracturing. It usually takes 2-3 minutes for the opening of the sand feeder to reach the predetermined sand concentration requirement, so it is difficult to effectively ensure the formation of proppant columnar slugs in the artificial fractures. At the same time, frequent opening and closing of the sand feeder is very likely to cause mechanical failure, resulting in failure of the engineering operation midway , it will also increase the mechanical wear of the sand conveyor and reduce the service life of the equipment

[0004] At present, there are still a large number of conventional sand mixer equipment in use in China. If we simply adopt the new research and development of the whole vehicle system or introduce foreign equipment, the existing equipment will be left idle.

In response to this situation, domestic institutions have carried out research work on pulse fracturing control related equipment. After patent retrieval, Wen Qingzhi from China University of Petroleum (East China) and others applied for the utility model of "Fracturing Pulse Sanding System Realizing High Conductivity". Patent, the system is a brand-new wet mixing circulation control system, which realizes pulse sand fracturing by controlling the flow of fracturing fluid. switching is restricted

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