Each year, the oil industry generates millions of barrels of wastes that need to be properly managed. For many years, most oil field wastes were disposed of at a significant cost. However, over the past decade, the industry has developed many processes and technologies to minimize the generation of wastes and to more safely and economically dispose of the waste that is generated. Many companies follow a three-tiered waste management approach. First, companies try to minimize waste generation when possible. Next, they try to find ways to reuse or recycle the wastes that are generated. Finally, the wastes that cannot be reused or recycled must be disposed of. Argonne National Laboratory (Argonne) has evaluated the feasibility of various oil field waste management technologies for the U.S. Department of Energy. This paper describes four of the technologies Argonne has reviewed. In the area of waste minimization, the industry has developed synthetic-based drilling muds (SBMs) that have the desired drilling properties of oil-based muds without the accompanying adverse environmental impacts. Use of SBMs avoids significant air pollution from work boats hauling offshore cuttings to shore for disposal and provides more efficient drilling than can be achieved with water-based muds. Downhole oil/water separators have been developed to separate produced water from oil at the bottom of wells. The produced water is directly injected to an underground formation without ever being lifted to the surface, thereby avoiding potential for groundwater or soil contamination. In the area of reuse/recycle, Argonne has worked with Southeastern Louisiana University and industry to develop a process to use treated drill cuttings to restore wetlands in coastal Louisiana. Finally, in an example of treatment and disposal, Argonne has conducted a series of four baseline studies to characterize the use of salt caverns for safe and economic disposal of oil field wastes.
Risk Analyses for Disposing Nonhazardous Oil Field Wastes in Salt Caverns