Positive cycle and reverse circulation dual-purpose three teeth roller bit

Abstract

The invention relates to a positive cycle and reverse cycle double-duty three cone bit which is adopted when in positive cycle drilling or reverse cycle drilling and is mainly composed of a crossover sub, a reverse cycle flow inducing hood, a drill bit body, a reverse cycle flow passage valve, a nozzle flow passage valve, a reverse cycle flow passage, a sealing cavity which controls the reverse cycle flow inducing hood to go upwards and downwards and the like, when in the reverse cycle drilling, the reverse cycle flow inducing hood goes downwards, simultaneously, the reverse cycle flow passage valve opens, the nozzle valve closes, and a flow inducing baffle plate directly induces annular fluid into the well bottom to strengthen the carrying cutting capacity of the fluid. When in the positive cycle drilling, reverse cycle flow inducing hood goes upwards, simultaneously, the reverse cycle flow passage valve closes, and the nozzle valve opens, which realizes the positive cycle drilling. In the process of drilling, Automatic switches between the positive cycle drilling and the negative cycle drilling are realized through the negative cycle flow passage valve, the nozzle flow passage valve and a sealing cavity passage according to the liquid flowing direction.

Description

technical field [0001] The invention relates to a tri-cone drill bit for both positive circulation and reverse circulation when liquid or gas is used as the circulation medium to carry out positive circulation and reverse circulation drilling in oil and gas well engineering. The drill bit is suitable for conventional mud drilling and gas drilling. and underbalanced drilling. Background technique [0002] With the continuous improvement and development of gas drilling and underbalanced drilling, the corresponding supporting technologies also need to be improved and redeveloped. The reverse circulation drilling technology is also a new technology under development. At present, no matter whether liquid or gas is used as the circulating medium for direct circulation or reverse circulation drilling, the corresponding direct circulation or reverse circulation drill bit can only be selected before the drill bit is lowered into the well, and the fluid circulation cannot be replaced ...

AI Technical Summary

Problems solved by technology

At present, no matter whether liquid or gas is used as the circulating medium for direct circulation or reverse circulation drilling, the corresponding direct circulation or reverse circulation drill bit can only be selected before the drill bit is lowered into the well, and the fluid circulation cannot be replaced automatically once the drill bit is lowered into the well direction unless tripping out to replace the bit

After the emergence of controllable drilling technology, its closed circulation system provides technical support for changing the circulation direction of drilling fluid at any time when drilling is needed. However, none of the currently used drill bits can automatically switch to a positive circulation flow as drilling needs. channel or reverse circulation channel drill bit

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