Drilling, Completion and Testing of Geothermal Wells CD-1 and CD-2, Caliente, Nevada

Abstract

Two geothermal test wells (CD-1, CD-2) were drilled in January, 1983, in Antelope Canyon to assess the potential for resource utilization by the City of Caliente's proposed space heating district. Both holes drilled into bedrock at 220 feet, encountered hot water in the upper part of the hole (40 to 100 ft) and cooler water below (100 to 210 ft). Lithologic logs reveal that a clay layer, in the vicinity of the temperature reversal, represents an aquitard that limits fluid mixing. A series of pump test, completed on CD-1 in February, 1093, indicate that the transmissivity of the thermal aquifer is very high. A pumping rate of 225 gallons per minute at 80° (178°F) may be considered a minimum. Drawdowns of 3 to 6 feet recovered instantly after pumping was stopped. Pumping of this well did to affect the water levels of two nearly observation wells. Significant temperature increase were recorded in both observation wells during the last few days of the tests. Chemical analyses of five water samples collected during the course of CD-1 pump tests indicate little or no change in composition over the period of testing, and demonstrate a high degree of correlation with nearly thermal fluids. Chemical geothermometers suggests that the maximum temperatures form this resocue range from 120 to 140°C. The highest temperature measured in this resource is 96°C.