Dual-channel drill bit with drilling fluid switching function

Abstract

The invention discloses a dual-channel drill bit with a drilling fluid switching function. The dual-channel drill bit includes a drill bit body and a dual-channel joint which are connected, the dual-channel joint includes a joint outer pipe, a joint inner pipe and a slide valve assembly located in an inner cavity of the joint inner pipe, an annular passage is arranged between the joint inner pipeand the joint outer pipe, and the joint inner pipe is provided with an inner pipe flow passing hole communicating with the annular passage; and the slide valve assembly includes a core pipe and a slide valve which is arranged between the joint inner pipe and the core pipe in sliding and sealing manners, the slide valve divides the inner cavity of the joint inner pipe into an inner pipe upper cavity and an inner pipe lower cavity, the top of the core pipe is closed, the bottom of the core pipe is open, the upper pipe wall of the core pipe is provided with a core pipe upper flow passing hole, and the lower pipe wall of the core pipe is provided with a core pipe lower flow passing hole. When the dual-channel drill bit is used for drilling, under the action of the pressure difference of high and low temperature drilling liquid, the core pipe upper flow passing hole and the inner pipe upper cavity are periodically connected and disconnected, the core pipe lower flow passing hole and the inner pipe lower cavity are periodically connected and disconnected, the high and low temperature drilling liquid is automatically switched and alternatively used, and variable temperature drilling and efficient rock breaking are achieved.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration tools, in particular to a dual-channel drill bit with a drilling fluid switching function. Background technique [0002] The drillability of rock is the ability of rock to resist the damage of drill bits, which is determined by the physical and mechanical properties of the rock itself and the rock-breaking ability of the drill bit. At present, the methods of increasing the drilling speed for high-drillability formations mostly focus on improving the rock-breaking ability of drilling tools, passively adapting to the rock drillability of the drilled formation, and the speed-up effect is not good. As a heterogeneous, discontinuous and anisotropic geological material, rock temperature has a significant impact on its physical and mechanical properties and deformation characteristics. Using the temperature effect to change the original physical and mechanical properties of the rock can ...

AI Technical Summary

Problems solved by technology

At present, the drilling speed increase methods for high drillability formations are mostly focused on improving the rock breaking ability of drilling tools, passively adapting to the rock drillability of the drilled formation, and the speed increase effect is not good

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