METHOD TO STRENGTHEN WELL AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2002 - IPC

FIELD: construction of wells, strengthening of oil and gas wells when presence of penetrable formations is proved. SUBSTANCE: scrapers are put on drill pipe string. Casing is attached to lower part of drill pipe string. Centralizer and centralizer-turbolizer are positioned on casing. Scrapers are set between them. Drill pipe string is run into well to setting. Clay coating is removed and well is gauged. Shaft of well is flushed. Centralizers and scrapers are mounted on casing string. Well is cased and scrapers are set close to penetrable formations. Reinforced cement stone is obtained in points of their setting. Device for implementation of method has drill pipe string, scraper for removal of clay coating prior to cementing, casing string with centralizers and scrapers put on it. Casing to gauge shaft of well is attached to lower part of drill pipe string. Scrapers to remove clay coating are put on casing between centralizer and centralizer-turbolizer. Scrapers of casing string are mounted for setting near penetrable formations, cavern pockets or between oil- and water-bearing beds and for obtainment of cement stone there. Scrapers have tubular body. Pairs of holes are drilled in body along its generating line. Scrapers are passed through these holes. Body of scrapers is fixed with the help of fixing member that comes in the form of hollow cylinder made interference fit inside body. EFFECT: simplified technology and enhanced reliability of device with use of simpler technical aids. 2 cl, 3 dwg