PROCESS OF WELL COMPLETION Russian patent published in 2003 - IPC

FIELD: oil and gas production, namely completion of wells fitted with packers. SUBSTANCE: process of well completion includes sinking of lifting pipes with packer to bottom of well and replacement of clay drilling mud with alleviative fluid. Hydrocarbon fluid is pumped into perforation interval, lifting string with packer is lifted to roof of productive formation and production string is perforated. Thereafter production formation is cleaned by method of counterflush under different conditions with maintenance of back pressure on formation over closed cycle with reiteration of flushing in reverse sequence and after this well is abandoned for technological stay. Then production formation is subjected to variable pressures in the course of 20 cycles. Well is flushed with maintenance of back pressure with simultaneous flushing of bottom bank in the course of two cycles as minimum. Inflow of fluid from formation is induced and packer is set. Behind-the- packer fluid is pumped into hole clearance, and non-freezing fluid is pumped into interval of permafrost rocks and then well is treated by oil gas flare. Flushing period in process of cleaning of production formation under each condition amounts to two cycles as minimum. Pressure is reduced gradually by 30-50 atmospheres. Value of depression while causing inflow and while well is treated by oil gas flare is chosen from condition P_for>P_sh≥0,7P_for where P_forP_sh are correspondingly formation and bottomhole pressures. Production string is perforated with adherence to condition P_for~P_sh. EFFECT: reduced expenses for completion of well in process of construction and repair thanks to elimination of fouling in production formation with drilling mud filtrates and to additional action on production formation and formation zone close to well. 1 dwg