Stepwise jet-drilling down hole control system

Abstract

The invention provides a stepwise jet-drilling down hole control system. The system comprises a speed controller and an anchoring mechanism, wherein the speed controller comprises a throttling cylinder, a throttling plunger and a piston rod; the throttling cylinder sleeves the piston rod; the upper and lower ends of the throttling cylinder are respectively hermetically connected with the upper and lower ends of the piston rod; a sealed annular hydraulic chamber is formed between the throttling cylinder and the piston rod; the throttling plunger is arranged inside the hydraulic chamber and fixedly sleeves the piston rod; a throttling clearance is formed between the outer wall of the throttling plunger and the inner wall of the throttling cylinder; through holes are formed in the piston rod in a manner of penetrating the piston rod along the axis; the piston rod and the throttling plunger can move axially along the throttling cylinder relative to the throttling cylinder; when the piston rod moves downwards along the axial direction, the anchoring mechanism can be opened by the piston rod. The stepwise jet-drilling down hole control system disclosed by the invention can be used for controlling the speed of a thrust during a jet-drilling process by a hydraulic cylinder and can also be used for realizing stepwise movement of a hydraulic cylinder propelling mechanism during a propelling process by the anchoring mechanism so as to realize long-distance feeding of a jet hose.

Description

technical field [0001] The invention relates to the technical field of water jet drilling for radial horizontal wells, in particular to a downhole control system for step-by-step jet drilling. Background technique [0002] Water jet radial drilling is a horizontal drilling technology with zero turning radius. The main procedures of this drilling technology include: 1. Casing window opening; 2. Drilling cement sheath; 3. Formation drilling. By drilling one or more clean fluid channels along the radial direction of the wellbore in the oil and gas well to add and expand the oil drainage area, so as to improve the characteristics of oil and gas flowing into the wellbore, and achieve increased production, increased injection and enhanced recovery. The technology has the following characteristics: deep penetration distance; large pore diameter, clean pore wall, strong flow capacity; little damage to the well body structure, no pollution to the formation; not easy to block and coll...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problems of jet drilling feeding speed control and jet hose feeding distance in the prior art, the present invention provides a step-by-step jet drilling downhole control system, which adopts hydraulic cylinder hydraulic propulsion mechanism and anchor Driven by a combination of mechanisms, not only can the thrust be controlled by the hydraulic cylinder to control the speed during the jet drilling process, but also the hydraulic cylinder propulsion mechanism can be stepped during the push process through the anchor mechanism, so that the jet hose can be realized long-distance feed

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