A combined screw drilling tool for drilling

Abstract

The invention provides a combined type screw drill for well drilling. The combined type screw drill comprises a screw drill body and a combined drill bit. The screw drill body comprises an outer cylinder, a drill motor and a cardan shaft assembly. A bypass valve is installed at the top end of the outer cylinder. The drill motor is installed in the outer cylinder and connected with the cardan shaft assembly in the axial direction towards the tail end of the outer cylinder. The combined drill bit comprises a main drill bit body and an auxiliary drill bit body. The main drill bit body is connected with a main driving shaft assembly. The main driving shaft assembly is connected with the drill motor through the cardan shaft assembly and sleeved with a protective cylinder. The auxiliary drill bit body is connected with an auxiliary motor. The auxiliary motor is connected to the exterior of the protective cylinder through a retracting assembly. The retracting assembly comprises a retracting rod, an auxiliary motor fixing rod and a retracting hydraulic rod. The retracting assembly capable of retracting and expanding is arranged, and transportation and well descending are facilitated; the main drill bit body and the auxiliary drill bit body are matched, so that the drilling efficiency is improved; the overload protection function is achieved, and damage to the main drill bit body and the drill motor is effectively avoided.

Description

technical field [0001] The invention belongs to the technical field of drilling, and in particular relates to a combined screw drilling tool for drilling. Background technique [0002] The screw drilling tool is a volumetric downhole power drilling tool that uses drilling fluid as power to convert hydraulic energy into mechanical energy. It is generally composed of a bypass valve, a motor assembly, a cardan shaft, a transmission shaft and a drill bit. Due to the diversity of geological environments, it is inevitable to encounter relatively hard rock formations during drilling. If the same power is maintained for continuous operation, it may cause damage to the drill bit or even the motor assembly, which not only increases the drilling cost, but also Reduced drilling efficiency. [0003] Therefore, it is an urgent problem for those skilled in the art to develop a screw drilling tool that can be applied to relatively hard rock formations and has excellent drilling efficiency....

AI Technical Summary

Problems solved by technology

Due to the diversity of geological environments, it is inevitable to encounter relatively hard rock formations during drilling. If the same power is maintained for continuous operation, it may cause damage to the drill bit or even the motor assembly, which not only increases the drilling cost, but also Reduced drilling efficiency

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