Development and separation effect of downhole oil/water separator in single-well injection and production

Key words:  single-well injection and production  downhole oil/water separation  suck rod pump  multicup isoflux  separator structure

Abstract:

The single-well injection and production technology is that the oil and water of the produced liquid are separated in the downhole, the separated water is injected into the formation of the same wellbore and the remaining oil concentrated fluid is lifted to the surface. Downhole oil/water separator is the key of this technology. High efficiency downhole oil-water separator is developed by multicup isoflow, coalescence, shallow pool and phase permeation gravity drive. The optimum structure of downhole oil-water separator (dip angle of settling cup bottom, cup edges, cup height, liquid inlet clearance height between adjacent cups), cup bottom shape and filter material in cup are optimized by laboratory test. The experimental results show that optimized separator has the best separating effect with dip angle 30°, 12 cup edges, cup height 15 mm, liquid inlet clearance height 0.5 mm, and 4 th oil wet filter material in cup.