Flexible drilling rod for radial horizontal well drilling

Abstract

A flexible drilling rod for radial horizontal well drilling comprises two end portion connectors and a connecting shaft which is connected between the connectors; the connecting shaft and the connectors are connected through universal shafts with meshed inner ball teeth and outer ball teeth; the inner ball teeth and the outer ball teeth are locked through a ball head cap; the connectors, the inner ball teeth, the outer ball teeth and the connecting shaft are provided with a common axial through hole; high pressure hoses are sleeved to the through hole; two ends of the high pressure hose are formed into dynamic seal through a bearing, a sealing ring and connector inner walls; the sealing ring is installed between the ball head cap and the outer ball teeth. The flexible drilling rod for the radial horizontal well drilling has the advantages of enabling an underground steering gear to be smoothly passed, enabling torque and bit pressure to be transmitted meanwhile to drive the drill bit to break rocks in a rotating mode, improving the well drilling speed of a horizontal section and circulating well drilling liquid due to the facts that the flexible drilling rod is formed by the plurality of metal universal shafts in a connecting mode, the hose pipe are installed inside the universal shafts, and a drill is connected to the lower end of the flexible drilling rod and the upper end is connected with a pipe column and meanwhile being simple and reliable in structural design, convenient to machine, large in transmitted torque, stable in operation and the like.

Description

technical field [0001] The invention relates to a flexible drill pipe used for radial horizontal well drilling in the fields of oil and gas drilling, coal bed methane drilling, geological exploration, mine drilling and other tool fields. Background technique [0002] As the development of oil and gas fields gradually enters the later stage, factors such as many old wells, poor oil and water wells, thin oil and gas layers, low permeability oil and gas layers, heavy oil layers, and difficulty in the recovery of remaining oil and gas seriously restrict the improvement of oil and gas field recovery in the later stage. The cost of infill wells and regeneration wells is high, and the production increase is not significant. The development of coalbed methane needs to maximize the exposed reservoir area, and at the same time reduce the comprehensive cost of drilling. For this reason, research on radial horizontal well drilling technology has been carried out successively at home and...

AI Technical Summary

Problems solved by technology

[0003] In view of the existing hose + hydraulic jet technology, the milling casing, cement sheath operation and hose insertion operation cannot be completed at the same time, the hose sliding drilling speed is slow, torque cannot be transmitted, and the hydraulic rock breaking efficiency for hard formations Low, poor stability of the pipe string during sliding drilling, etc., the purpose of the present invention is to provide a flexible drill pipe for radial horizontal well drilling at construction sites such as oil and gas drilling, coalbed methane drilling, geological exploration, and mine drilling

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