Bottomhole steering device for ultra-short radius horizontal well drilling and its construction method

Abstract

A bottom-hole steering device for ultra-short-radius horizontal well drilling and a construction method thereof. The bottom-hole steering device includes an inner pipe assembly and an outer pipe assembly, and the inner pipe assembly includes a tubing string, a gyroscope positioning nipple, The inner tube and drum assembly, the middle part of the inner tube is equipped with a support body, and the outer edge of the lower part is provided with a positioning groove. The outer tube assembly includes the outer tube, slips, friction blocks and support plates, and the slips The inner edge of the outer tube can be opened under the support of the support body, a friction block is installed in the middle of the outer tube, and a positioning pin matching the positioning groove is fixed, and a support plate is connected to the lower part; under the action of the friction block, the present invention The outer pipe is relatively stationary. When the oil pipe is lifted, lowered and rotated on the ground, the inner pipe moves up and down and rotates under the action of the positioning pin and the positioning groove, and at the same time drives the support body to move up and down, so that the anchoring, orientation and steering of the downhole pipe string The actions are all controlled by lifting, lowering and rotating the tubing string on the ground, and all radial and horizontal wellbores can be drilled in one trip.

Description

technical field [0001] The invention relates to the technical field of oil and coal bed gas drilling equipment, in particular to a bottom-hole steering device for ultra-short-radius horizontal well drilling and a construction method thereof. Background technique [0002] High-pressure water jet radial horizontal well is a cutting-edge technology in the drilling industry. It can turn from vertical to horizontal in a vertical well section with a radius of 0.3m or less to ensure that the horizontal well enters the target layer accurately; it can be used on a certain depth reservoir level Drill multiple horizontal wellbores in different orientations, and also drill multiple radial horizontal wellbores on multiple different depth levels, which can increase the oil drainage area, improve single well production, oil and gas recovery and single well control reserves. Ultra-short-radius horizontal well drilling technology has high operating efficiency and low cost, and is suitable f...

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Problems solved by technology

[0003] The radial well drilling technology that has been put into use at present (CN101660391A, CN101748970B) has the defect of small borehole diameter in the horizontal well section, and the reservoir contact area is small, so it is difficult to maximize the advantages of horizontal wells. The large diameter radial horizontal well technology (CN2128666Y , CN2615322Y) downhole anchoring and steering all have different defects, the steering device is controlled by the hydraulic device of the wellhead through the hydraulic pipe, the operation is complicated, and the downhole tool is difficult to change the orientation; After drilling a horizontal well section, the pipe string must be pulled out and the pins reinstalled before the next wellbore can be drilled. The operation period is long and the risk is high

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