Eccentric center-adjustable reducing stabilizer

Abstract

The invention relates to an eccentric adjustable stabilizer with a variable diameter, which is used for being combined with an underground directional or anti-tip drilling tool, can be used in match with a rotary directional drilling system, and can realize the automatic underground diameter variation and the eccentric adjustment, improve the level of the drilling technique and increase the economic benefit. The technical scheme is as follows: a compression sleeve barrel, a cross joint, a diameter variation mechanism, a cross joint, a gear shifting piston and a gear shifting mechanism are sequentially installed on the inner cavity of a housing from the top to bottom; five fixed cylindrical bodies are installed on a protruded arris of the outer part of the housing in an axial direction, five moveable hard alloy cylinders are respectively installed in the inner cavities of the other two protruded arrises in an axial direction, the front end of a gear shifting dowel pin in the gear shifting mechanism is inserted in the gear shifting slot of a gear shifting cam body, and gear shifting slots with special traces are arranged on the outer periphery of the gear shifting cam body. The gearshifting cam body can be moved up and down, can be rotated, can automatically realize the diameter variation and the eccentricity underground, and can realize step gear shifting and stepless gear shifting. The eccentric adjustable stabilizer with the variable diameter has the advantages of high intensity, favorable leak-proofness and long service life, and can be used for the drilling construction of directional wells and straight wells, thereby improving the overall drilling technical and the economic benefits.

Description

technical field [0001] The invention relates to a special downhole tool used for petroleum and geological drilling, which is an eccentric adjustable variable diameter stabilizer used for downhole directional or anti-deviation drilling tool combination and used in conjunction with a rotary steering drilling system. Background technique [0002] During the drilling process, in order to control the trajectory of the wellbore and prevent the well deviation, stabilizers are usually used. Because of the fixed structure of the traditional stabilizer, the only way to achieve eccentric diameter change is to stop drilling, pull out the drill, and run in the drill, which increases the impact of the mud on the well wall. During the soaking time, it is easy to get stuck when drilling and run into resistance, which not only prolongs the construction period, reduces the drilling efficiency, but also causes well collapse and blowout accidents, which make the wellbore scrapped and cause huge ...

AI Technical Summary

Problems solved by technology

The existing pitching-type variable-diameter stabilizer is not perfect, and the ball needs to be pitched from the ground when used, the operation is complicated, and the number of diameter changes is limited

Existing eccentric stabilizers only have fixed eccentric type, but no adjustable eccentric type

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