Field Test of Produced Water Treatment With Polymer Modified Bentonite

Abstract

Abstract The combination of ET Ventures' ET #1 and granular activated carbon consistently and effectively removed hydrocarbons from Tensleep formation produced water in a 24-hour test at Teapot Dome oil field. Specific findings are that ET #1:–Reduced Total Petroleum Hydrocarbon (EPA Method 418.1) to non-detectable levels.–Reduced Oil and Grease (EPA Method 413.2) to non-detectable levels.–Reduced soluble hydrocarbons: Benzene, Ethylbenzene Toluene, and Xylene (BTEX-EPA method 8020) to barely detectable levels. BTEX was below detectable limits after the combination of ET #1 and granular activated carbon. Introduction This report describes the results of a test conducted at the Rocky Mountain Oilfield Testing Center (RMOTC) of a product manufactured and marketed by ET Ventures, L.L.C. This product, ET #1, is designed to adsorb hydrocarbons from wastewater. The test conducted at RMOTC was intended to document the ability of ET #1 to:–Adsorb a relatively large quantity of hydrocarbons from oilfield produced waters carrying a free oil sheen.–Tolerate the wide variations in hydrocarbon concentrations typical of oilfield operations.–Adsorb soluble hydrocarbons in the BTEX family under these same circumstances. A 24-hour test was designed in which produced water from the Tensleep formation was flowed through a three-stage treatment system composed of two stages containing ET #1 and a final polishing stage containing granular activated carbon (GAC). Product Description ET #1 is a product generally referred to as a polymer modified bentonite or an organoclay. This group of materials is manufactured by binding an amine polymer onto bentonite clay and drying it in a granular form. The polymer binds to the bentonite's ionic surfaces and converts the clay from a hydratable form to an oil-wet, hydrocarbon adsorbent material. Other clays are also used for the manufacture of organoclay, depending on the application and location of mineral deposits. Organoclay is commonly used in the upstream sector of the petroleum industry for removing hydrocarbons from refinery process water, but it has seen little use in petroleum production. Many other industries also use it, including shipping and dockside servicing, carwashes, and others dealing with an oily wastewater stream. Organoclays have also been tested for treating ground and surface water for other organic chemicals such as PCBs and pesticides. Present and Future Constraints on Oilfield Produced Water. Oilfield produced water is an important source of surface water in the arid western U.S. The discharge of produced water is permitted under the National Pollutant Discharge Elimination System (NPDES), which may be administered by the U.S. E.P.A. or by a state program. In addition, other state and federal programs come into play to generally prohibit the presence of a free oil sheen or staining of the shoreline of surface impoundments. Netting may also be required over surface impoundments in order to protect migratory birds from hydrocarbon contamination. P. 137^