A low-friction variable-diameter hydraulic thruster

Abstract

The invention relates to a low-friction-drag variable-diameter hydraulic thruster used for petroleum and natural gas drilling. According to the technical scheme, an upper connector is connected with an auxiliary cylinder through threads, the auxiliary cylinder is connected with a main cylinder through threads, the main cylinder is connected with a spline cylinder through threads, a piston is arranged in the auxiliary cylinder, a second piston cushion cover, a first piston ring and a first piston cushion cover are sequentially arranged on the piston, a first press cap and a first anti-loose cap are both connected with the piston through threads, a mandrel is arranged in the main cylinder and the spline cylinder, a semi-ring is arranged in the middle of the mandrel, a fourth piston cushion cover, a second piston ring and a third piston cushion cover are sequentially arranged on the head of the mandrel, a second pressing cap and a second anti-loose cap are connected with the mandrel through threads, a nozzle base is located between the piston and the mandrel, a nozzle is arranged in the nozzle base, four steel ball bases are evenly distributed between the mandrel and the spline cylinder, and steel balls are arranged in the steel ball bases. According to low-friction-drag variable-diameter hydraulic thruster, drilling pressure which is high enough, stable and uniform can be obtained by a drill bit in the true sense, the bridge over phenomenon can be prevented, and the low-friction-drag variable-diameter hydraulic thruster is used for drilling.

Description

technical field [0001] The invention relates to a low-friction variable-diameter hydraulic thruster used for oil and gas drilling operations. Background technique [0002] In conventional drilling operations, both rotary table drilling and bottom hole motor drilling rely on the weight of the drill string to apply the drilling pressure. However, in the process of drilling highly deviated wells and horizontal wells, with the increase of the inclination angle, it becomes more and more difficult to rely on the weight of the drill string to apply the WOB, and the frictional resistance of the borehole wall is also increasing, which directly affects the drill string. In addition, the drill string is subject to more severe operating conditions, which are prone to vibration, especially the longitudinal vibration of the drill string, which leads to the inability to keep the WOB constant, thereby reducing the mechanical The drilling speed will cause early failure of the drill bit, and...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is: in order to solve the problem that the drill bit is difficult to pressurize during the drilling process of highly deviated wells, slim hole sidetracking wells and sidetracking horizontal wells, so that the drill bit can really obtain a sufficiently large, stable and uniform drilling pressure, And reduce the friction of the drill string, play a good role in shock absorption, prevent sand plugging, reduce the occurrence of drill stuck accidents, and achieve efficient drilling. A low-friction variable-diameter hydraulic thruster is specially provided

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