Composite Drilling Method for Drag and Torsion Reduction in Complex Structure Wells

Abstract

The invention discloses a complex structural well drag-reduction wrenching-reduction compound drilling method. An underground drag-reduction wrenching-reduction device is arranged between an upper-portion drilling rig and a measurement-while-drilling drilling assembly combination, and therefore the upper-portion drilling rig can rotate independently relative to the measurement-while-drilling drilling rig; a reaction torque balancing device is arranged between a power drilling rig and a drill bit, and the disturbance of the reaction torque generated by a power drilling rig to a tool face is eliminated. The complex structural well drag-reduction wrenching-reduction compound drilling method has the advantages that the drag-reduction wrenching-reduction device can change the drill string sliding drilling into rotary drilling during the guiding drilling process, the friction resistance and the torque loss are reduced, and the occurrence rate of complex situations that the drill string is stuck and clamped is reduced; the reaction torque balancing device can effectively eliminate the influence of the reaction torque generated by a power drilling rig on the tool face, the tool face is controlled to be stable, the well track control accuracy is improved, the well body quality is improved, and complex structure well efficient drilling is achieved.

Description

technical field [0001] The invention relates to a drilling method for a well with a complex structure in the technical fields of oil and gas drilling, geological exploration and mine drilling. technical background [0002] In the process of oil and gas drilling, geological exploration, and mine drilling, wells with complex structures such as pilot wells, horizontal wells, highly deviated wells, and extended-reach wells are more and more widely used, which puts forward higher requirements for drilling technology. Existing drilling systems for complex wells mostly use upper drilling tools (also known as drill strings), measurement-while-drilling drilling tool assemblies, mud power motors, anti-torque balance devices, and drill bit assemblies. The sliding drilling system powered by the mud motor performs drilling operations. At this time, the mud power motor drives the drill bit to rotate and drill, but the drill string itself does not rotate. However, due to the effect of its ...

AI Technical Summary

Problems solved by technology

Existing drilling systems for complex wells mostly use upper drilling tools (also known as drill strings), measurement-while-drilling drilling tool assemblies, mud power motors, anti-torque balance devices, and drill bit assemblies. The sliding drilling system powered by the mud motor performs drilling operations. At this time, the mud power motor drives the drill bit to rotate and drill, but the drill string itself does not rotate. However, due to the effect of its own weight, it lies flat on the bottom of the well, resulting in high frictional resistance and difficult to be effective. When drilling pressure is applied, downhole safety accidents such as sticking are prone to occur, especially in the process of directional drilling such as deep well pilot wells, extended reach wells, long horizontal section horizontal wells, and unconventional wellbore, where the frictional torque is large and the drill string Difficulties in lifting and lowering, and difficulty in pressurizing when drilling are particularly prominent

[0003] Because of the rotary steerable drilling technology in foreign countries, it has been able to overcome the friction and sticking problems during steerable drilling. The research on rotary steerable drilling technology is being actively carried out in China, but the cost of rotary steerable drilling technology is too high, and the drilling conditions in use require Higher, so the scale of its promotion and application is limited to a greater extent

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