Patent ID: 6776231
Filing Date: 2004-08-17
Classification: B08B,E21B

Abstract:
A casing scraper for cleaning the interior wall of a well casing, comprising a generally cylindrical body defining an uppermost end adapted for connection to a drill string and having a plurality of scraping or scouring elements disposed around the outer surface thereof for contacting the interior wall of the well casing and a bore extending through the cylindrical body, one end of which bore is adapted for connection to a source of cleaning fluid and the other end of which bore is connected to a tail pipe extending below the lowermost end of the cylindrical body, which tail pipe has at least one opening in it through which cleaning fluid may be circulated into the well casing, wherein the casing scraper further comprises filtration means located above the openings in the tail pipe and remotely operable means for selectively directing the flow of cleaning fluid from passing outside the filtration means to passing through the filtration means.