METHOD OF LIFTING WELL FLUID AND COMBINED WELL LIFT FOR REALIZATION OF THIS METHOD Russian patent published in 2000 - IPC

FIELD: methods of lifting well fluid; intra-well type gas lifts. SUBSTANCE: method includes creation of intra-well type gas lift in lower stage of lifting, separation of gas-and-fluid mixture in tail 7 of gas lift before lifting it through tail 7, lifting fluid through pump 7 before intake of pump 4 by separated gas, passing the entire volume of gas-and-fluid mixture, stepped bypass of gas and fluid through cavities of pump 4 followed by lifting the fluid over tubing string by gas separated from fluid. Combined well lift includes upper and lower lift stages; lower lift stage includes tail 7 whose lower end holds gas separator 9 secured by means of sleeve 8 provided with axial passages 10 connecting gas separator 9 with cavity of tail 7. Upper end of tail 7 is connected with suction line of pump 4. In upper lift stage, pump 4 is double-plunger unit with hollow plungers 13 and 14 connected by means of rod 15. Arranged in plungers 13 and 14 are plate valves 17 and 18 whose shut-off members are rigidly secured over end surfaces of rod 15. EFFECT: enhanced efficiency of pumping-out fluid with the aid of intra-well type gas lift together with sucker-rod pump due to complete use of energy of gas separated from well fluid from well bottom as far as wellhead. 4 cl, 2 dwg