The Application of Petroleum Engineering Science And Technology to Subsurface Disposal of Liquid Industrial Wastes

The direct application of oilfield technology to subsurface disposal of industrial wastes has directed attention to numerous technical problems. These arise because of (a) the special design and operation required for wells intended for disposal of highly corrosive fluids, such as pickle liquor, from steel companies; (b) special precautions that must be taken to avoid injection of an immiscible phase with the aqueous waste (a small percentage phase with the aqueous waste (a small percentage saturation of an immiscible fluid in the disposal formation will seriously decrease the relative permeability to water); (c) special treatment of the formation and waste when swelling clay is present in the disposal formation; and (d) the limiting volume of some formations. Some of these problems encountered by chemical industries are described. Introduction Subsurface disposal of liquid waste has been practiced by the petroleum industry since about 1920 when it was applied to oilfield brines. Currently the U.S. oil industry injects about 17 million B/D into subsurface formations. In contrast, a survey of liquid waste injection by the chemical industry, made in 1962 by the U.S. Bureau of Mines, showed that 32 wells were being used to inject 136,000 B/D of industrial waste. Estimates from recent national survey, indicate that about 150 wells are being used to inject approximately 675,000 B/D of industrial wastes into geologic formations ranging in depth from 1,000 to 8,000 ft. Thus, in 8 years the volume of industrial waste injected underground has increased five times. The successful injection of waste by the chemical process industry shows that subsurface waste disposal offers a solution to extremely difficult liquid waste disposal problems. Concentrated acid wastes, caustics, problems. Concentrated acid wastes, caustics, solutions of salts, organic phosphates, phenols, chlorinated hydrocarbons and mixed organic and inorganic wastes are being disposed of economically by injection into geologic formations. There are many advantages of subsurface over surface methods of waste disposal. Capital investment and operating costs are lower, the surface area required for the plant is less, seasonal temperature variations plant is less, seasonal temperature variations have less effect on the system, chemical treatment of the waste is minimal, and generally the only physical treatment required is filtration.