METHOD FOR INITIAL EXPOSING OF COMPLEX CAVERNOUS-FRACTURE OF CARBONATE OIL AND GAS SATURATED FORMATION WITH HORIZONTAL SHAFT OF LONG LENGTH Russian patent published in 2016 - IPC E21B21/08 

FIELD: oil industry.

SUBSTANCE: invention relates to oil and gas industry, particularly to methods for initial exposing by horizontal wells productive formations with hydrocarbon saturation. Method of determining boundaries of allowed values of "depression" and "repression" ranges based on mining and geological data obtained during drilling and development of previous wells, during drilling of horizontal shaft with closed circuit of bottom-hole pressure in well in turn, first, is maintained below formation pressure within specified range of depression, then bottom-hole pressure is increased above formation within a given "repression" range. Combined permissible range of combined dynamic bottomhole pressure is described by mathematical expression. Control of bottomhole pressure is performed by throttling at wellhead. Bottom-hole pressure in well is kept within predetermined "depression" and "repression" ranges based on an algorithm for alternate switching of well development and absorption mode, making it possible to conduct wiring, recess of well at complex oil and gas saturated formation under complicated conditions.

EFFECT: higher efficiency of development of deposits of oil and gas in complex cavernous-fracture carbonate oil and gas saturated formation.

1 cl, 2 dwg