Method for detecting pigs in oil pipelines uses acoustic sensors mounted on outside of pipe wall to detect interruption of ultrasound signals reflected from inside of pipe and to detect signal from acoustic unit on pig

摘要

Method for detecting and identifying pigs (6) in oil pipelines (1) uses acoustic sensors (4, 5) mounted on the outside of the pipe wall. In a first stage interruption of ultrasound signals reflected from the inside of the pipe is detected and in a second stage a signal from an acoustic unit (11) on the pig is detected and used to identify it. An independent claim is included for apparatus for carrying out the method in which the sensors are linked to a processor (14).