Rotary drill string directional drilling short section and drilling method

Abstract

The invention relates to a rotary drill string directional drilling short section and a drilling method, and belongs to the field of drilling tools. The drilling section comprises a shell, a cylinderbody arranged in the cylinder body shell, a switch assembly configured to enable the cylinder body and the shell to be separated and make relative rotation when the switch assembly is opened and to enable the cylinder body and the shell to be connected and make synchronous rotation when the switch assembly is closed, and a well wall friction mechanism, wherein the well wall friction mechanism comprises a first connector connected with the cylinder body and a movable piece arranged in the first connector, and the movable piece is configured to move in the radial direction according to the displacement of the drilling fluid flowing through the short section, so that different friction forces are selectively applied to the well wall. During directional drilling, a switch is turned on, a drillrod can be driven by a rotary disc to rotate, the reaction torque of a screw drilling tool below the short section is balanced by the friction force generated by the well wall friction mechanism, thetool face is in a stable state, the effect of directional drilling of a rotatable drill column is achieved, and therefore the underpinning effect is effectively reduced, and the mechanical drilling speed is increased.

Description

technical field [0001] The invention relates to a directional drilling nipple with a rotatable drill string, in particular to a nipple used in directional drilling operations of directional wells and horizontal wells. The invention also relates to a drilling method. Background technique [0002] In directional wells and horizontal wells, the wellbore trajectory is mainly controlled by screw drilling tools. Generally speaking, the drill string does not rotate to ensure the stability of the tool face of the screw drilling tool. However, this will result in greater axial friction between the drill string and the borehole wall. Especially for horizontal wells with long horizontal sections and extended reach wells, axial friction will lead to problems such as poor transmission of drilling pressure and low ROP. [0003] Chinese patent document 201620363357.0 discloses a downhole pipe string rotation control switch, which includes an upper joint, a switch assembly, a housing and...

AI Technical Summary

Problems solved by technology

Generally speaking, the drill string installed under the switch is about 300 meters long. The friction of the drill string is greatly affected by the movement state and the downhole environment. During work, the friction force often changes, causing the screw drilling tool to be unstable. situation arises

The drill string with a length of about 300 meters cannot be rotated, which shortens the rotation ratio of the drill string and affects the effect of reducing friction and increasing speed

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