Ball-throwing type controllable wall scraper and method for cleaning inner wall of sleeve

Abstract

The invention provides a ball-throwing type controllable wall scraper and a method for cleaning the inner wall of a sleeve. The ball-throwing type controllable wall scraper comprises a control system, a cutter system, at least one first steel ball and at least one second steel ball, wherein the first steel balls and the second steel balls control the control system to work. The first steel balls are thrown into the control system, so that the first steel balls push a second piston to move downwards, when the second piston moves downwards and enables all cutter feeding blocks to move downwards to push cutters on all rings to pop out of cutter through holes, buckle structures between a first piston and the second piston are connected, and then wall scraping operation can be conducted; the second steel balls are then thrown into the control system, the second steel balls drive the buckle structures to separate from each other, the second piston moves upwards under the action of all reset springs, the cutter feeding blocks also move upwards, so that all the cutters retract to the cutter through holes, and then the wall scraper is restored to an initial state. According to the ball-throwing type controllable wall scraper, at least two steel balls different in size are thrown into a tool, so that the cutters pop out or retract, obstacles on the inner wall of the sleeve are smoothly removed, downhole potential safety hazards are effectively removed, the cutters will not get stuck, and the service life of the cutters is long.

Description

technical field [0001] The invention relates to the technical field of petroleum workover and downhole operation, in particular to a ball-throwing controllable wall scraper and a method for cleaning the inner wall of casing. Background technique [0002] In oil workover and downhole process operations, the wall scraper is used to remove cement blocks, cement sheaths, hard wax, various salt crystals and deposits, perforation burrs and casing corrosion remaining on the inner wall of the casing. Produced iron oxide and other substances, so as to enter various downhole tools unimpeded. The working mechanism of the wall scraper is to fix the cutter on the tool. The installation of the cutter is required to be larger than the outer diameter of the tool itself, and smaller than the inner diameter of the casing. The drilling tool moves up and down in the casing, and the cutter is used to remove residues on the inner wall of the casing. Cement blocks and other things on the ground, ...

AI Technical Summary

Problems solved by technology

Common wall scrapers can be divided into rubber cylinder type and spring type. The cutter of conventional wall scraper is fixedly installed on the tool. In downhole tools, it is usually encountered that objects such as large cement blocks are stuck on the cutter, or When encountering a small-sized wellbore, the existing wall scraper cannot pass through, causing downhole complications and accidents such as stuck pipe

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