Push-lean type rotary steering drilling system

Abstract

The invention discloses a push-lean type rotary steering drilling system comprising a drill bit, a rotary shaft, a turning part, a push-lean assembly, a transmission and a control unit. The rotary shaft comprises an upper rotary shaft and a lower rotary shaft. The turning part is arranged on the outer side of the rotary shaft in a sleeving mode. The push-lean assembly comprises a plurality of push-lean parts arranged at intervals in the circumferential direction of the turning part. The transmission device comprises a transmission mechanism driving the push-lean parts to stretch out of the turning part. The transmission mechanism comprises a driving electromagnetic gear arranged on the upper rotary shaft, and a driven electromagnetic gear arranged on the turning part. A motion conversionunit is further included and converts rotary motion of the driven electromagnetic gear into liner motion of the push-lean parts. The control unit is used for modulating a magnetic field, so that the driving and driven electromagnetic gears achieve linkage through magnetic coupling and operate with an adjustable transmission ratio. According to the push-lean type rotary steering drilling system, circuits elements, conductive sockets and the like do not need to be arranged on the turning part, the structure of the turning part is simplified, the size of the turning part is reduced effectively, flexibility of underground feed motion is improved, and cost is lowered.

Description

technical field [0001] The present application relates to the field of drilling, in particular to a push-by rotary steerable drilling system. Background technique [0002] In order to obtain natural resources stored underground, drilling exploration is required. In many cases, the wellbore and the derrick are not aligned, but need to form a certain offset or curvature, which forms a horizontal or vertical offset or other types. The process of complex boreholes is called directional drilling. The process of controlling the direction of the drill bit in the process of directional drilling is called steering. There are two types of modern directional drilling: slide-steering and rotary-steering. There are also two commonly used rotary-steering technologies, one is pointing-steering and the other is push-steering. [0003] The existing push-by rotary steerable drilling system consists of a surface monitoring system and downhole tools. The downhole tool is divided into three m...

AI Technical Summary

Problems solved by technology

Corresponding circuit components are installed in the non-rotating outer cylinder. On the one hand, electrical interfaces such as conductive sockets or openings for introducing wires need to be provided at the non-rotating outer cylinder. On the other hand, corresponding circuit components need to be installed. The installation structure of other structural components, the limit structure, etc., and the need to reserve installation space for circuit components, resulting in a complex structure and an increase in the size of the non-rotating outer cylinder, resulting in an increase in the size of the entire directional drilling system. The increase in the size of the whole machine not only brings about an increase in cost, but more importantly, it affects the flexibility of the downhole feed movement of the steerable drilling system

[0007] In addition, the downhole environment is complex and harsh. During the drilling process, in order to prevent downhole impurities from entering the non-rotating outer cylinder through the joint gap between the rotating mandrel and the non-rotating outer cylinder, the non-rotating outer cylinder and the lower sub The normal operation of the electronic components in the rotating outer cylinder is affected, and the corresponding sealing structure needs to be designed, etc., the sealing cost is greatly increased, and for the technology of joint deflection driven by the hydraulic mechanism installed in the non-rotating outer cylinder, generally through The hydraulic cylinder drives the piston, and the piston drives the corresponding pushing part to expand and contract to drive the deflection of the lower joint. The expansion and contraction of the pushing part is normal in the downhole. The outer cylinder needs to be equipped with a corresponding dynamic sealing structure, which is high in cost and poor in reliability

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