METHOD FOR PLUGGING-UP WELLS Russian patent published in 1994 - IPC

FIELD: plugging-up wells. SUBSTANCE: plugging device is lowered into well with its discharge hole positioned against lower boundary of interval to be plugged, then, pulsator is engaged. Hydraulic pressure pulses formed by pulsator in above-piston space are transmitted through piston to grouting mortar in space and through it to plug which moves downward under action of pulse pressure that is accompanied by shearing members and displacement downwards of slider and case together with plug. In so doing, case comes off collar which is set to working position due to its flexible forces. Further on, grouting mortar under action of pressure executes pulse motion from working hollow through hole to well to fill fractures, pores and caverns in rocks. Upon completion of plugging of interval h, the device is lifted in well bore to bypass drilling mud from hole clearance above packer through channel and hole in seat, that excludes piston effect. Lifting is carried out step by step alternating it with stops. To decrease consumption of plugging materials, during lifting of plugging device between stops, mud injection may be discontinued. To increase reliability of well plugging-up with the plugging device having container, subject to registration is moment of complete forcing of grouting mortar from container and packer position corresponding to this moment, and duration t₀ of last stop, and if collar is found at the moment of complete forcing out of grouting mortar form container below the interval roof and/or stop duration t₀ is t₀<t, run is repeated. When grouting of intervals of large thickness by several runs of grouting device with container, registered during each run are moment of completion of forcing out of grouting mortar from container and position of packer in plugged interval corresponding to this moment, and duration t₀ of last stop of plugging device. And when executing next run of plugging device, its lowering is discontinued after installation of packer at distance h≅ l above roof of interval plugged during previous run if duration of last stop was equal to t₀≥ t, or after packer is installed at depth at which it was at the moment of complete forcing out of grouting mortar from container during previous run, when duration of last stop was equal to t₀<t. EFFECT: higher efficiency. 4 cl, 2 dwg