Horizontal well diameter-adjustable screw drill dedicated for coal bed gas

Abstract

The invention discloses a horizontal well diameter-adjustable screw drill dedicated for coal bed gas. The horizontal well diameter-adjustable screw drill can increase the drilling diameter and comprises a liquid inlet joint, a hydraulic motor assembly, a universal shaft assembly and a transmission shaft assembly, a variable-diameter piston assembly is connected to the lower end of the transmission shaft assembly, and the lower end of the variable-diameter piston assembly is connected with a milling shoe through a transition joint; and the variable-diameter piston assembly comprises a T-shaped piston rod, a piston pressing plate, a reset spring and a pressing plate fixing bolt, an oval piston is arranged at the upper end of the T-shaped piston rod, an inclined face is arranged at the lower end of the oval piston, an oval annular inner cavity matched with the oval piston is formed in the lower end of the transmission shaft assembly, the oval piston is limited in the oval annular inner cavity through the piston pressing plate and the pressing plate fixing bolt, a spring installation cavity is formed in the piston pressing plate, and a reset spring is arranged in the spring installation cavity.

Description

technical field [0001] The invention relates to the technical field of screw drilling tools, in particular to an adjustable-diameter screw drilling tool for horizontal wells dedicated to coalbed methane. Background technique [0002] With the continuous deepening of oil and gas exploration and production, it is more difficult to ensure the supply of conventional oil and gas resources. Accelerate the development of unconventional oil and gas resources, increase oil and gas production, and extend the life cycle of the oil industry. Medium and long-term oil and gas security is of great significance. Unconventional oil and gas resources mainly include tight rock oil and gas, shale gas, shale oil, and coalbed methane. Unconventional oil and gas resources are widely distributed in my country and have large reserves, the most important of which is the exploitation of coalbed methane. The traditional mining method of coalbed methane is vertical well mining, which has low output and...

AI Technical Summary

Problems solved by technology

However, when the deviation occurs and the well wall expands and narrows during drilling, and the operation index cannot be completed, the drilling hole diameter cannot be adjusted at any time, and the drilling tool must be pulled out to replace the drill bit, which increases the workload, reduces the operating efficiency, and is prone to downhole accidents

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