Self-driven deflection bit based on gas underbalanced drilling

Abstract

The invention discloses a self-driven deflection bit based on gas underbalanced drilling. The self-driven deflection bit comprises a ballscrew. One end of a restoring spring is fixed to a ballscrew body of the ballscrew. The other end of the restoring spring is connected with the bottom of a direction-changeable telescopic claw. The ballscrew is sleeved with the direction-changeable telescopic claw. The top of the ballscrew is connected with a bit body. When the bit is used, motion between the bit body and the direction-changeable telescopic claw is transmitted through the ballscrew; when anchor jaws are unfolded under the effect of hydraulic force and supported on a well wall, the anchor jaws can be further wedged into the well wall through wedge angles at the tops of the anchor jaws, and larger driving force is provided for the bit body; and the self-driven deflection bit provided by the invention has the advantages of borehole operation adaptability and real-time direction changing.

Description

technical field [0001] The invention relates to the improvement of the drill bit structure for downhole drilling in the petroleum industry, in particular to a self-driving deflectable drill bit based on gas underbalanced drilling. Background technique [0002] The underbalanced drilling methods currently used include air drilling, atomization drilling, foam drilling, and air-filled drilling. Among them, air drilling mainly uses a high-power compressor to deliver circulating high-pressure or large-displacement air flow to the bottom of the well, and uses air as a circulating medium to carry out cuttings. The gas underbalanced drilling technology uses gas as the drilling circulation medium, which not only has low cost but also greatly saves drilling costs. Since the drilling medium is circulating gas instead of drilling circulating fluid, gas drilling can not only prevent the drilling fluid from leaking and polluting the oil layer, but also prevent the occurrence of drilling ...

AI Technical Summary

Problems solved by technology

However, realizing and maintaining underbalanced drilling requires special steam injection equipment, well control equipment, surface treatment equipment for produced fluid, measurement-while-drilling equipment, solid control equipment, etc., and the applicable well types of this method are also limited.

Gas underbalanced drilling is sometimes prone to problems such as wellbore instability, excessive well deviation, drilling tool failure, downhole explosion, formation water, etc.

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