METHOD OF WELL DRILLING Russian patent published in 2017 - IPC E21B7/00 E21B21/00 

FIELD: construction.

SUBSTANCE: invention relates to well construction and can be used in sinking of well shaft through zone of rock breaks. Method of well drilling involves drilling of well shaft by drilling assembly with downhole motor using hydraulic downhole motor in area of horizon with rock breaks, periodical reciprocating of drilling string with simultaneous rotation of drilling string, drilling of horizon with rock breaks using drilling fluid, lifting of drilling assembly above horizon with rock breaks, trip or development of drilled interval, lifting of drilling assembly from well, lowering of drilling assembly in well, determination of intervals of drilling assembly placement, performing treatment of placement intervals, lifting of drilling assembly from well. During lowering of drilling assembly first flushing is performed at depth of 400 m for 1.5 cycles, further flushing is performed every 300 m of lowering during 1.5 cycles. During drilling control lifting of drilling assembly is made to length of drill separation lead pipe at least 1 time per hour. If observing puffs, well drilling is stopped, intensive flushing is made with reciprocation of drilling tool with overlapping of sleeves until puffs end, drilled interval is processed, lowering is continued, control liftings are made at least every 0.5 hour of drilling. At extension of tightening is cleansing drilling run is made by drilling assembly, every 50 m of drilling drilling assembly is lifted up to interval of inclination angles of 35°, well borehole is processed up to bottom to remove crust and slime. Before extension of drilling assembly flushing is made for at least 1.5 cycles, speed of lowering and lifting operations in range of horizon with rock breaks is no more than 0.2 m/s, removal of slime during drilling is set in volume of 0.4–0.6 m³ at every 9 m of drilling. After opening of productive formation reciprocating with flushing are made until removal of slime. Lifting of drilling assembly is performed with topping up every 250–300 m. After lowering of assembly and processing of interval of complications viscoelastic composition is injected from face, borehole is templated and processed.

EFFECT: elimination of sticking of drilling assembly during well drilling through zone with rock breaks is provided.

1 cl, 1 ex