The U.S. Department of Energy (DOE) Gladys McCall well in Cameron Parish, Louisiana, was drilled in 1981 and subsequently tested as part of the DOE Geopressured-Geothermal Energy Program. The well produced geo-pressured brine containing dissolved natural gas from the Lower Miocene sands at a depth of 15,150 to 16,650 feet (4 618 to 5 075 m). More than 25 million barrels of brine (4 (E+06) m3) and 727 million standard cubic feet of natural gas (20.6 (E+06) m3) were produced in a series of flow tests between December 1982 and October 1987 at various brine flow rates up to 28,000 barrels per day (4 452 m3/d). Short-term flow tests for the Number 9 Sand found the size of the reservoir to be too small for long-term production, so it was plugged off. Initial short-term flow tests of the Number 8 Sand found a suitably large reservoir with a permeability of 113 to 132 millidarcies (md) (111 to 130 (E-03) μm2) and an indicated volume of 430 to 550 million barrels of brine (68.4 to 87.5 (E+06) m3). The long-term flow and buildup test found that the reservoir was much larger than was measured by the short-term flow test. Test data and numerical simulation of the flow and buildup tests through 1990 required the initial reservoir volume, as measured by the short-term tests, to be connected to additional reservoir volume with lower permeability. A total reservoir volume of about 7.8 billion barrels (1.2 (E+09) m3) was determined with an effective permeability of the distal parts of the reservoir in the range of 0.2 to 20 md (0.2 to 20 (E-03) μm2). Detailed chemical analysis of the brine and gas found the brine to be slightly undersaturated with gas at about 29 SCF/STB (5.16 m3/m3). The produced gas/brine ratio was invariant with production time and flow rate. Calcium carbonate scale formation in the well tubing and separator equipment was controlled by the injection of a scale inhibitor into the flow line and by twice successfully injecting inhibitor "pills" directly into the reservoir. Corrosion and/or erosion of piping and equipment was also significant.

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