METHOD FOR DEWAXING OIL WELL TUBINGS Russian patent published in 1997 - IPC

FIELD: oil producing industry. SUBSTANCE: excessive tension of rope above preset value with scraper blocked in paraffin deposits in lifting is monitored with the help of transducer of limit rope tension, and upper position of scraper, with the help of transducer of scraper upper position. Rope sagging with scraper blocked in deposits during its lowering is detected by deflection of lever with roller to definite position. Respective signal arrives at control unit. The latter gives command for rope unwinding and holding scraper on deposits until it forces through, and scraper continues moving downward. wedging of rope in winch drum is detected by deflection of lever with roller to definite position. In so doing, transducer of rope tension position gives signal to control unit. The latter gives command for stopping rope unwinding, then, for scraper lifting for preset time until rope is released. EFFECT: eliminated disturbance of cycle of pipe cleaning due to control of all parameters of the process in automatic mode. 1 dwg