FIELD: oil and gas industry.
SUBSTANCE: method includes assembling a pipe string with screw downhole motor and a bit cutter, lowering the tubing string with the screw downhole motor and the bit cutter into the well until drilling of well equipment is completed, creating circulation by pumping flushing fluid through the downhole motor, the bit cutter and inter-string space into well holding tank, drilling of well equipment, lifting the string of pipes with downhole motor and the bit cutter from well. A flexible tube is used as pipe string, and the screw downhole motor, an oscillator, the bit cutter is mounted at the wellhead on the lower end of the flexible tube string. The pipe string is lowered into the well at a rate of 15 m/min with unloading of not more than 10000 N and spreading every 50 m without pumping flushing fluid until the downhole equipment to be drilled is reached. The flexible tube string is lifted by 15 m. The screw downhole motor starts with injection of flushing fluid into the flexible tube string with pump unit pressure at 15.0-20.0 MPa with consumption for operation of the screw downhole motor and creating the circulation. The flexible tube string is lowered into the well at 2 m/min rate until the upper interval of the downhole equipment is reached. The downhole equipment is drilled by the bit cutter without exceeding the maximum permissible load on the bit cutter and without exceeding the maximum permissible pressure drop differential. The inner walls of the well are worked out in the interval of the drilled downhole equipment by three-time lowering and lifting of flexible tube string at 2 m/min rate without interrupting the circulation of the flushing fluid. The flexible tube string is lifted at 5 m/min rate by 400 m above the upper interval of the downhole equipment to be drilled. Injection of the flushing fluid is stopped, and a process break is taken for 2 h for sludge settling. During the process break, the flexible tube is reciprocated every 20 minutes. The production string is gauged by lowering the flexible tube string with the screw downhole motor, the oscillator and the bit cutter and cutting process without injecting the process fluid to a depth of 20 m below the lower interval of the downhole equipment drilled in the well. The flexible tube string with the screw downhole motor, oscillator, and the bit cutter are removed.
EFFECT: efficiency and reliability of the method, extend functionality, and increased mechanical speed of the drilled of the downhole equipment.
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