(300c) Beneficial Uses of Highly Saline Produced Water

Over the course of his career Dr. Cohen has provided many contributions to the science and application of desalination to improve water quality. A particularly challenging water source is the highly saline water from many oil and gas production operations, such as those in the Permian and Delaware Basins in West Texas. Typically salinities are in excess of 100,000 mg/L total dissolved solids. The potentially available water, however, is large with projections suggesting between 10 and 20 million barrels of day being produced in the Permian and Delaware Basins for the next 25 years with perhaps half of that being used within the oil producing areas for water flooding and fracturing. West Texas is also forecast to have significant shortages of water in coming years – totaling about 12 million barrels per day of agricultural needs by 2050 suggesting that produced water, if treated to an appropriate level of quality, could significantly aid in satisfying the potential unmet demand for water in the region.

The high levels of salts, however, pose economic and technical challenges to desalination and specific salts are of concern for toxicity, and equipment scaling. Moreover, the produced water often contains trace organics and substantial amounts of inorganic carbon and ammonia. These constituents influence the energy efficiency of the desalination processes as well as increase requirements for pre and post desalination treatment. Offsetting these impediments to beneficial uses of produced water are the economic advantages and reduced seismicity of avoiding deep well disposal and the potential for extraction of rare earth elements and other valuable minerals.

The presentation will examine these issues and explore the feasibility as well as technical approaches to significantly increasing the beneficial use of oil and gas produced water in the Permian and Delaware Basins as well as the applicability of these approaches to other oil and gas basins around the world.