Pumping-pressure reverse-circulation well drilling method and system

Abstract

The invention relates to the field of machinery, in particular to a pumping-pressure reverse-circulation well drilling method and a system. The pumping-pressure reverse-circulation well drilling method comprises the steps of filling well drilling liquid into an annulus of a shaft; enabling the well drilling liquid to flow into a drill bit through a water hole of the drill bit; enabling the well drilling liquid to flow into a drill column from the drill bit and flow out of the drill column. By adopting the pumping-pressure reverse-circulation well drilling method and the system, the theoretical drilling depth can be infinitely great when the pressure resisting capacity of a well opening sealing device and a fracture pressure value of a stratum are enough.

Description

Technical field [0001] The invention relates to the field of drilling machinery, in particular to a pump-pressure reverse circulation drilling method and system. Background technique [0002] With the increasing difficulty of exploration and development of oil and gas resources, drilling engineers and technicians are facing various technical problems. The low drilling rate of drilling machinery is one of the key factors restricting exploration and development costs. The low drilling rate during the drilling of shale gas horizontal wells causes the open hole section to be soaked in the drilling fluid for a long time, and the well wall collapses seriously; tight sandstone gas drilling rate The low cost has led to a sharp increase in drilling costs, and the traditional speed-up methods such as bit selection, drilling tool assembly optimization, and well structure optimization are also difficult to achieve satisfactory results. During the drilling of highly deviated wells, horizonta...

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Problems solved by technology

Low drilling speed of drilling machinery is one of the key factors restricting the cost of exploration and development. During the drilling of shale gas horizontal wells, the low drilling speed causes the open hole section to be soaked in drilling fluid for a long time, and the well wall collapses seriously; the drilling speed of tight sandstone gas Low drilling costs lead to a sharp increase in drilling costs, and traditional methods of speed-up such as bit selection, drilling tool combination optimization, and wellbore structure optimization are also difficult to achieve satisfactory results

During the drilling process of highly deviated wells, horizontal wells, and extended-reach wells, due to the existence of cuttings beds, poor wellbore purification, repeated breaking of cuttings, increased frictional torque of the drill string, severe casing wear, and stuck pipe A series of problems such as frequent accidents have caused a sharp increase in drilling costs

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