Patent attributes
A casing scraper can include extendable scraper elements, and an actuator that extends the scraper elements after the actuator retracts the scraper elements. The actuator extends the scraper elements and retracts the scraper elements after application of respective pressure differentials in a well. A method of operating a casing scraper can include extending scraper elements into contact with an interior surface of a casing after a predetermined pressure differential is applied without obstructing an interior flow passage, and then retracting the scraper elements after another predetermined pressure differential is applied. A well system can include a casing scraper with one or more extendable scraper elements, and an actuator that operates in response to manipulation of pressure differentials. The actuator operates the casing scraper only after at least a predetermined pressure differential has been applied for at least a predetermined period of time.