Water treatment schemes for injection water flooding recovery processes in carbonate reservoirs

摘要

Disclosed are water treatment apparatus and processes for the generation of injection water from seawater and produced water. The first water treatment apparatus includes a reverse osmosis (RO) unit that treats the seawater, a pretreatment unit that pretreats the produced water, and a carrier gas extraction (CGE) unit or dynamic vapor recompression (DyVaR) that treats the pretreated produced water and generates fresh water. The fresh water and the RO permeate are mixed with a portion of the seawater to generate the injection water. A second water treatment apparatus includes a reverse osmosis (RO) unit and a nanofiltration (NF) that treats the seawater in parallel, a pretreatment unit that pretreats the produced water, and a CGE unit or DyVaR unit that treats the pretreated produced water and generates fresh water. The fresh water and the RO permeate are mixed with the NF reject to generate injection water.