METHOD OF OIL RECOVERY Russian patent published in 1997 - IPC

FIELD: oil producing industry; methods of oil recovery from wells with complicated operating conditions. SUBSTANCE: fluid is lifted from the well by pump which is lowered on the tubing with bypass valve. Tubing is lower to under the level of product. Associated petroleum gas is accumulated into the tubing-casing annulus. Gas excessive pressure is released into flow through bypass valve. Bypass valve is installed below the zone of wax deposition and formation of sand plugs. The depth of location of bypass valve is determined by the formula given in the invention description. Gas is supplied monotonically at excessive pressure. It is effected by closing the channel for release and supply of gas into flow line, and its value is controlled by the difference of pressure satisfying the condition Pm-Pb ≥ 0.5 MPa. EFFECT: provision of restoration of optimal operating conditions of unfortunate wells, increased their production rate, reduced specific energy consumption in oil lifting due to maximum utilization of the energy of associated petroleum gas entering the pump from the formation together with oil. 1 dwg, 2 tbl