Casing Scraper
MODEL “BC” CASING SCRAPERSProduct No.: BI 620-03
Description:
Casing Scraper is used to remove mud or cement sheath, imbedded bullets, perforation burrs, rust, mill scale, paraffin and similar substances from the inside walls of the casing.
The importance of keeping this vital “working surface” clean and smooth is because all subsequent operations in the well are affected in one way or another by the condition of the casing ID. An imbedded bullet or sharp burr can damage a swab cup or packing element; less-than-full calculated inside diameter can be responsible for premature set of close-tolerance tools; and hardened rotary mud or a thin cement sheath left after drilling out following a cementjob may prevent the slips of a pack-off tool from engaging the wall of thecasing.
Features/Advantages:
Rugged Construction: The body of the Scraper is machined from solid bar stock, and blade blocks are of case hardened steel for absolute maximum ruggedness and strength.
Rotating or Reciprocal Action: The Casing Scraper operates successfully either when rotated or reciprocated vertically on Drill Pipe or Tubing. It can also be run on cable-tool drilling line with jars and sinkers when ordered with a cable-tool joint pinup.
Cannot “Screw” Down During Rotation: The angle and direction of shear of the scraping edges of the blades are such that the Scraper cannot “Screw” down past burrs as it rotates.
Operation:
For removal of cement sheath, the Scrapershould be installed between the drill bit and the drill collar so that both the drilling-out and the sheath removal can be accomplished at the same time. It is good practice to maintain circulation while these operations are being conducted. The Scraper should be run completely through the perforated section without rotation, then pull back up and make a rotary run through the section. Casing Scrapers can be operated without rotary equipment by simply running completely through again. If the perforation density is relatively high, it is a good policy to rotate the tubing a quarter of a turn with tongs.
A Junk Basket is some time run above the Casing Scraper. If the mud pumps do not have the capacity to maintain the necessary circulation, the Basket may be mounted below the Scraper.
Sources:- https://www.botilindia.com/wp-content/uploads/2019/02/Casing-Clean-Up-Tools-1.pdf