METHOD FOR DRILLING WELL IN DISASTROUS LOST CIRCULATION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2019 - IPC E21B21/00 

FIELD: mining.

SUBSTANCE: group of inventions relates to drilling of oil and gas wells in complicated conditions. Method involves a cyclic process of drilling a well with a drilling tool with a bit with washing with water until water is consumed in receiving benches with stops for a set of formation water to intake bins from the well. Drilling is carried out until incomplete consumption of water in receiving bins. In the cycles of stopping the upper part of the drilling tool is removed from the well, the upper part of the drilling tool is removed; a jet pump, self-sealing packer under it, a branch pipe and the lower part of the drilling tool with a bit are lowered to the well on the production pipe string. Bit is installed in interval above zone of its possible clamping, and jet pump is installed at 10–20 m below established level of formation water. Working water from receiving bins to jet pump is supplied along process string. Reservoir water from the annular space under the self-sealing packer is lifted to the wellhead along the annular space above the self-packing packer and supplied to receiving tanks. After filling receiving bins with formation water, supply of working water is stopped and a pipe string is withdrawn from the well with a jet pump, self-sealing packer and branch pipe, connecting and lowering the upper and lower parts of the drilling tool with the bit and lowering the drilling in the interval of the zone of catastrophic absorption with washing with formation water until incomplete consumption of water in the receiving bins, after which the above cycle of stopping a set of formation water into receiving bins from the well and drilling is repeated, starting with extraction of the upper part of the drilling tool from the well.

EFFECT: increased efficiency of method due to reduction of duration of works in cycles of shutdown to set of formation water and expansion of application area.

2 cl, 2 dwg