Downhole device using hydraulic jets of parallel tubes to flush pulverized coal

Abstract

The invention relates to a downhole device using hydraulic jets of parallel tubes to flush pulverized coal for the field of development of a gas field and a coal-bed gas field. The downhole device consists of a throat diffusion tube 1, an outer cylinder 2, O-shaped sealing rings 3 and 9, a high-pressure nozzle 4, copper washers 5 and 11, a high-pressure chamber 6, a sleeve 7, sand flushing teeth 8, a mixing nozzle 12 and a guide connector 10. The guide connector 10 is connected with the high-pressure chamber 6 in a welding way; the internal circular surfaces of the upper end and the lower end of the high-pressure chamber 6 are respectively connected with the high-pressure nozzle 4 and the mixing nozzle 12 via threads; the internal circular surfaces of the upper end and the lower end of the outer cylinder 2 are respectively connected with the external circular surfaces of the throat diffusion tube 1 and the high-pressure chamber 6 through threads; and the sleeve 2 is connected with the sand flushing teeth 8 in a welding way and connected with the high-pressure chamber 6 through threads. The structure of the device is simple, part of power liquid is used for exerting impact on downhole pulverized coal so that the pulverized coal is fully mixed with formation fluid; and the rest of power liquid is sprayed by the high-pressure nozzle to form a negative pressure area, the formation liquid is sucked in a rolling way after being mixed into a returning liquid tube, and thus the downhole pulverized coal can be discharged.

Description

Technical field: [0001] The invention relates to a technology for removing coal powder, coal coke, coal slime and other solid particles not deposited in a coalbed gas well and restoring production capacity, and belongs to the technical field of oil and gas field and coalbed gas field development. Background technique: [0002] In the process of coalbed methane well drainage and gas recovery, due to the coal seam structure and stratum structure, it is inevitable to produce solid substances such as coal powder, coal slime and coal coke. If these solid substances are not produced The liquid is carried out of the wellbore, and a large amount of deposits at the bottom of the coalbed methane well will lead to buried pumps and stuck pumps, resulting in suspension of drainage. In order to resume production, the solid substances deposited at the bottom of the well must be discharged to the ground. [0003] At present, the coal powder is mainly scooped out mechanically on site. Since ...

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Problems solved by technology

[0004] The purpose of the invention is to: overcome the shortcoming of the low efficiency of the current coalbed gas well workover operation; change the current situation that the coalbed gas well workover operation mode is single

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