CONTROLLED PRODUCED WATER DESALINATION FOR ENHANCED HYDROCARBON RECOVERY

摘要

ABSTRACT Processes, systems, and techniques for treating produced water drawn from a subterranean formation. The produced water is provided and contains dissolved solids and magnesium, calcium, and sodium ions. The produced water is desalinated using an electrically-driven membrane separation apparatus that includes alternating anion exchange membranes and cation exchange membranes defining opposing sides of alternating product and concentrate chambers. The desalinating involves flowing the produced water through the product chamber, flowing a second water through the concentrate chamber, and applying an electric potential across the cation and anion exchange membranes as the produced and second waters flow through the product and concentrate chambers, respectively. The product water is consequently produced and has a total dissolved solids content of between 300 mg/L and 8,000 mg/L, a total concentration of calcium ions and magnesium ions less than 100 mg/L, and a sodium adsorption ratio of 20 to 90.