A downhole oil/water separation system is operational since 1997 in the Eldingen field located east of Hannover (Germany). The installation is the first successful demonstration of the downhole separation concept outside North America. The well produces light oil with a high watercut from a consolidated sandstone reservoir. Originally eighty cubic metres of fluids were produced daily with the assistance of a beam pump. The new well completion consists of a hydrocyclone for oil/water separation and of electric submersible pumps for drawdown and for re-injection of the separated water. The downhole separator increases the effective capacity of the flowline thereby debottlenecking the Eldingen production system. By recompleting the well, net oil has increased by a factor of three, whilst net water has decreased threefold. In the first year of operation re-injection of water, separated downhole, didn't cause any damage to matrix permeability, however, an increase of the watercut in the project area is observed.
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