A Push-Back Rotary Steerable Drilling System

Abstract

The present application discloses a push-on type rotary steerable drilling system, which includes a drill bit and a rotating shaft. The rotating shaft includes an upper rotating shaft and a lower rotating shaft; a steering part is sleeved outside the rotating shaft; A plurality of pushing parts arranged at intervals in the circumferential direction; a transmission device, including a transmission mechanism that drives the pushing parts to extend out of the steering part; the transmission mechanism includes a driving electromagnetic gear arranged on the upper rotating shaft and a driven electromagnetic gear arranged on the steering part; It also includes a motion conversion unit, which converts the rotational motion of the driven electromagnetic gear into the linear motion of the pusher; and a control unit, which is used to modulate the magnetic field to achieve linkage between the main and driven electromagnetic gears through magnetic coupling, and to make the main and slave The moving electromagnetic gear operates with an adjustable transmission ratio. The system in this application does not need to install circuit components and conductive sockets on the steering part, simplifies the structure of the steering part, effectively reduces the size of the steering part, improves the flexibility of the downhole feeding movement, and reduces costs.

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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