Double-wall reverse-circulation drilling tool

Abstract

The invention relates to a double-wall reverse-circulation drilling tool which is applied to the field of oil and gas drilling engineering. The requirement of a double-wall drilling rod reverse-circulation drilling technology is met, and meanwhile the efficiency of removing rock debris at a shaft bottom is improved. The tool is characterized in that the upper end of an outer cylinder body is in screw thread connection with the lower end of an upper connector, and the lower end of the outer cylinder body is in screw thread connection with the upper end of a connector; a pushing bearing is arranged on the step surface in the middle of an inner cavity of the connector; a left-rotation spiral blade is arranged in the middle of an outer circle of an outer rotor, and a right-rotation spiral blade is arranged on an outer circle of an inner rotor; the outer rotor is placed in the inner cavity of the outer cylinder body; the inner rotor is placed in the inner cavity of the outer rotor, a male screw thread at the lower end of the inner rotor is in screw thread connection with a female screw thread of the hole bottom of a step hole of an inner cavity of a jetting drill, and a male screw thread at the lower end of the outer rotor is in screw thread connection with a female screw thread of a hole opening of the step hole of the inner cavity of the jetting drill. According to the double-wallreverse-circulation drilling tool, drilling fluid and rock debris directly enter the inner cavity of the outer rotor from a reflowing hole of the jetting drill and then enter an inner pipe of a double-wall drilling rod, the rock breaking torque is large, the rock debris at the shaft bottom is removed in time, and the efficiency of removing the rock debris at the shaft bottom is high.

Description

technical field [0001] The invention relates to a double-wall reverse circulation drilling tool used in the field of oil and gas drilling engineering. Background technique [0002] In the field of oil and gas drilling engineering, double-walled drill pipe reverse circulation drilling (Reel Well drilling) technology is a new drilling technology, based on double-walled drill pipe, drilling fluid is pumped into the well from the double-walled drill pipe annulus to clean the well Bottom, carrying cuttings from the internal drill pipe back to the ground, so as to realize the closed-loop circulation of drilling fluid. The double-walled drill pipe is composed of inner and outer layers of drill pipe (called inner pipe and outer pipe). The channel for pumping the flushing medium; the central hole of the inner pipe is used to discharge the flushing medium and fix it as a whole, and the screw thread of the outer pipe between each double-walled drill pipe is connected to ensure the tra...

AI Technical Summary

Problems solved by technology

However, in the application process of the current double-wall drill pipe reverse circulation drilling technology, the drilling fluid enters the inner tube of the double-wall drill pipe from the upper flow adapter of the bottom hole assembly. On the one hand, the pressure difference of the drilling fluid from the drill bit to the upper flow adapter Large, on the one hand, the cuttings carrying efficiency is low, and the cuttings at the bottom of the well are difficult to be removed in time

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