Refined Conceptual Modeling and a New Resource Estimate for the Salton Sea Geothermal Field, Imperial Valley, California

摘要: Interim results of a new conceptual modeling effort for the Salton Sea geothermal field (SSGF), in Trough southernmost California, show that this resource: (1) is hotter at depth (up to least 389 degrees Centigrade 2 km) than initially thought; (2) probably driven by still-cooling felsic intrusion rather (or addition to) primitive mafic magmas previously invoked role; (3) may be just most recent phase hydrothermal activity inititiated site as soon began form ~4 m.y. ago; (4) thermally prograding; and (5) spite 30 years' production has yet experience significant pressure declines. Thick 400 m) intervals buried extrusive rhyolite are now known common central SSGF, where temperatures also hottest. The considerable thicknesses these concealed volcanics lack corresponding intermediate-composition igneous rocks imply coeval granitic originated crustal melting gabbroic magmatic differentiation. In brine-saturated, sedimentary sequence, plutons inevitably would engender convective systems. Results preliminary numerical system broadly similar one active SSGF suggest could underlie deep wells part no more kilometer. model indicate static temperature profiles selected have taken 150,000 200,000 years develop, far longer 20,000 cited previous investigators probable age field. two viewpoints conceivably reconciled if likely long history here were punctuated prolonged. Configurations portions current still undergoing thermal expansion. A newly consolidated, field-wide reservoir database enabled us reassess field's ultimate resource potential with an unprecedented level detail confidence. value, 2330 MWe (30+ year lifetime assured) closely matches earlier estimate 2500 (Elders, 1989). If fully developed, might day satisfy household electrical-energy needs fourth present population State California.