The presentation would include a discussion of the opportunities and challenges associated with converting an "unusable by-product" of hydrocarbon production into a valuable water resource. The presentation would analyze the quantity and quality of California oil field produced water in relation to the location and needs of potential users, and evaluate the economics of treating produced water for use by industrial, municipal and agricultural entities. Oil production generates a significant by-product, commonly known as "produced water". As the oil is produced from an oil field, produced water can reach > 90 percent or more of the fluids pumped from an oil well. In 1999, approximately 204 AF/day was generated in the Los Angeles Basin (Los Angeles and Orange counties), 80 AF/day generated in the Coastal Basin (Monterey to Ventura along the Pacific Ocean), and 303 AF/day generated in the Kern County oil fields. The most prevalent method of handling oil field produced water is through deep well injection. The disposal cost for produced water at the Placerita oil field in Santa Clarita, California was equivalent to $775/AF in 1996 dollars and energy costs. The following factors make consideration of non-traditional sources of reclaimed water more attractive: · The reliability of existing water supplies has decreased and many public water agencies are actively seeking new sources of water. · New drinking water regulations are increasing water costs and are creating viable private water markets. · "Water wheeling" statues (Water Code Section 1810 et seq.) establish a framework for water exchange agreements. · Treatment technologies (particularly membranes) have advanced significantly over the past several years. The ideal scenario is when a water purveyor is looking for a new source of reclaimed water that can supply the needs of non-potable users freeing up the potable water resources. Collaborative public/private sector approaches appears to be the best strategy for identifying and delivering this new reclaimed water resource. Government funding may be available to assist public agencies for developing this resource. Compelling economic drivers are needed as incentives for oil companies to consider reclamation of produced water. Typically, there will not be a positive rate of return associated with the sale of reclaimed produced water. These drivers can include: 1. Improved crude oil recoveries and reserves by de-watering the oil production reservoir. 2. The lack of disposal capacity for produced water disposal using current practices. 3. Avoided costs associated with current disposal practices. The water use must be determined before selecting treatment technologies to convert produce water into a useable water resource. The water use dictates the water quality requirements and these requirements determine the appropriate treatment technologies. Treatment technologies may include membrane or thermal processes. Membrane technologies are generally preferable for water with a TDS <10,000 mg/L, and thermal technologies are generally more viable at higher TDS levels. The key water quality issues of converting produced water to a useable water resource appear to be total dissolved solids (TDS), hardness, organics, ammonia, silica, borate, and water temperature. Other critical factors include regulatory and institutional risks, uncertainties of developing water exchange agreements, potential permitting, regulatory, jurisdictional issues, and the public acceptance of reuse of treated oilfield produced water.
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