Hydraulic scraper (HS)

The hydraulic scraper is designed to clean the internal surface of casing or tubing strings from slurry cake, rust, paraffin, and other deposits. Design features and operating principle The scraper features a one-piece tubular body with box and pin threads at the upper and lower ends. Slip-type blades are installed in longitudinal slots along the body. The blades feature wear-resistant, hardened cutting edges and are capable of radial movement. Under pressure from the circulation fluid pumped through the tubing, the piston actuates the blades, extending and pressing them firmly against the surface to be cleaned, ensuring tight contact. The blades are arranged in two tiers with three blades per row, ensuring 100 % coverage of the pipe’s internal circumference. Blade retraction is ensured by a compression spring. Each blade is retained in its slot by a split ring, secured with screws. Cleaning is performed during running in hole on drill or tubing string. As it moves downhole, the blades slide along the internal surface, scraping off irregularities and contaminants. A single standard scraper body can accommodate interchangeable blades of different sizes. Each blade size is specifically designed for cleaning casing of a particular nominal diameter.