String structure of coal-bed gas well and coal-bed gas well system

Abstract

The invention discloses a string structure of a coal-bed gas well and a coal-bed gas well system, and belongs to the field of technologies for developing coal-bed gas. The string structure comprises a tail tube, an oil tube reducing connector, a tubular pump, a pumping rod, an oil tube and an echo mark. The end surface of the bottom of the tail tube is opposite to the inner bottom surface of a casing, the tail tube is fixedly connected with a pump barrel of the tubular pump by the oil tube reducing connector, the pump barrel of the tubular pump is fixedly connected with the oil tube, and the pumping rod is positioned in the oil tube and is fixedly connected with a plunger of the tubular pump; the echo mark fixedly sleeves the outer side wall of the oil tube; the inner diameter of the tail tube is larger than the inner diameter of the pump barrel of the tubular pump and is larger than or equal to the inner diameter of the oil tube. The string structure and the coal-bed gas well system have the advantages that water in the tail tube in the integral string structure flows at the lowermost flow rate, solid particles in the water can be settled, water in the tubular pump flows at a high flow rate, accordingly, the solid particles cannot be deposited in the tubular pump, and the problem that existing solid particles are easy to deposit in existing tubular pumps can be effectively solved.

Description

technical field [0001] The invention relates to the technical field of coalbed methane development, in particular to a pipe column structure of a coalbed methane well and a coalbed methane well system. Background technique [0002] Coalbed methane wells can mine the coalbed methane stored in the coal seam. The coalbed methane is mainly adsorbed on the inner surface of the coal seam pores. The coalbed methane well pumps out the water in the coal seam to reduce the pressure of the coal seam below the desorption pressure of the coal, making the adsorption state The coalbed methane is desorbed into free coalbed methane, which diffuses and flows into the casing of the coalbed methane well, and then is discharged from the casing. [0003] The pipe string structure of CBM wells is mainly used to pump water in the coal seam. The pipe string structure includes the pump body and the screen pipe. The screen pipe is fixedly connected to the lower end of the pump body. The water in the c...

AI Technical Summary

Problems solved by technology

[0005] 1. Some fine solid particles can pass through the screen and are easily stuck in the pump body, affecting the normal operation of the pump body;

[0006] 2. Solid particles that cannot pass through the screen are easy to block the screen, which affects the pipe string structure to pump water in the coal seam; if the pump body does not have a screen and pumps water directly, solid particles will be deposited in the pump body, and a large number of pump inspection operations will be performed , which destroys the principle of stable drainage and gas recovery of coalbed methane wells, and at the same time increases development costs

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