METHOD OF DEEP-WELL PUMPING OIL RECOVERY AND DEEP-WELL PUMPING UNIT USED FOR REALIZATION OF THIS METHOD Russian patent published in 1999 - IPC

FIELD: oil industry; recovery of high-gas factor oil from wells with gas or gas-condensate caps. SUBSTANCE: pumping unit includes deep-well pump, gas separator, controllable cutoff valve, electric contact pressure gauge and timer which are arranged in line venting the petroleum gas from annulus space into discharge pipe line; they are heat-insulated and are provided with heating system. Method consists in determination, setting and maintenance of optimal annulus pressure to ensure optimal conditions for operation of deep-well pumping unit equipped with gas separator. Determination of optimal annulus pressure is effected on basis of results of deep-well testing on the condition of minimum magnitude of first derivative of "annulus pressure - dynamic level" function. Optimal annulus pressure is set at such level that dynamic level changes by no more than 50 to 100 m at fluctuations from 1 MPa to nominal magnitude. Optimal annulus pressure is maintained by means of controllable cutoff valve which is controlled in its turn by means of electric contact pressure gauge (by upper and lower pressure limits) and timer (by interval of time of accumulation of free gas in annulus space and duration of its discharge into discharge oil line). EFFECT: avoidance of open flowing of oil in inter-tube space and gas breakthrough via pump; reduced probability of paraffin deposition in annulus space and hydration of check valve; extended service life of deep-well pump; stable operation of well. 6 cl, 2 dwg