An intelligent casing scraper for ultra-deep wells

Abstract

An ultra-deep well casing intelligent wall scraper is characterized in that it mainly includes: a first scraper group, a first group of fish-scale scraper blades, a first pressure chamber, a first low-density steel ball, a first ball seat, The first wall scraper, the second scraper group, the second group of fish-scale scraper blades, the second pressure chamber, the second low-density steel ball, the second ball seat, the second wall scraper, the third scraper group, the second Three sets of fish-scale scrapers, the third pressure chamber, the third low-density steel ball, the third ball seat, and the third wall scraper; the first set of fish-scale scrapers, the second set of fish-scale scrapers, the third The phase angle between the fish-scale scraper blades is 60°, and the outer diameters of the first low-density steel ball, the second low-density steel ball and the third low-density steel ball decrease in turn. The steel ball opens any scraper group to realize non-rotating 360° intelligent wall scraping operation with multi-sections and multi-diameter inner casings in ultra-deep wells. The invention is applicable to the technical field of ultra-deep and complex oil and gas well drilling and completion engineering.

Description

technical field [0001] This patent relates to the technical field of complex oil and gas well drilling and completion engineering, in particular to an intelligent casing scraper for ultra-deep wells. Background technique [0002] In oil and gas well workover and downhole process operations, wall scrapers are used to remove cement blocks, hardened mud cakes, hard wax, bitumen, various salt crystals and deposits, perforation burrs and casings remaining on the inner wall of the casing. Iron oxide and other substances produced after pipe corrosion, so as to enter various downhole tools unimpeded. The working principle of the wall scraper is to fix the cutter on the scraper body, and the cutter is required to be larger than the outer diameter of the tool itself and slightly smaller than the inner diameter of the casing. The pipe string drives the scraper to rotate and move up and down in the casing, and the cutter It is used to remove residues (such as cement blocks, iron filing...

AI Technical Summary

Problems solved by technology

[0003] Traditional casing scrapers, such as American GRANT5600 and 5500 casing wall scrapers, under the action of compression springs, the maximum outer diameter of the blade is larger than the inner diameter of the casing, and cannot work with drilling plugs, milling, drilling tools and other tools at the same time , and during the running process, it is usually encountered that large cement blocks and other objects are stuck on the cutter, or small-sized well holes, resulting in the failure of the wall scraper to pass through, resulting in complicated downhole accidents such as drill sticking, so it is mainly suitable for Shallow well, not suitable for deep well and ultra-deep well scraping operation

Invention patent (CN201220389571.5) proposes a new type of all-in-one hydraulic wall scraper, which can hydraulically open the blade after the wall scraper enters the well to perform wall scraping operations, and realize drilling, milling, grinding, and well drilling. Multiple operations can be completed in one trip of the pipe string downhole, but the wall scraping efficiency of this invention is low, and it cannot achieve 360° no dead angle wall scraping on the inner wall of the casing, and the wall scraper is easily blocked when it is pulled out

[0004] Invention patent (CN201310436952.3) proposes a ball-throwing controllable wall scraper and a method for cleaning the inner wall of the casing. By putting in two steel balls of different sizes for wall scraping, the tool can be ejected and retracted, and the inside of the casing can be cleaned smoothly. The barriers on the wall can effectively eliminate hidden safety hazards in the well, and the cutter will not be stuck or blocked. However, the downhole structure of the invention is complex, difficult to process and assemble, and inconvenient to operate downhole. The structure of the scraper itself is prone to falling off and failure, especially in deep wells. And the situation is more obvious in ultra-deep wells

[0005] Existing casing wall scraping equipment either has a good cleaning effect but is complex in structure and difficult to process and assemble, or has a simple structure but poor cleaning effect, which cannot meet the needs of deep and ultra-deep wells

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