Final Scientific / Technical Report, Geothermal Resource Exploration Program, Truckhaven Area, Imperial County, California

Layman Energy Associates, Inc.

Layman Energy Associates, Inc.

关键词: Geothermal Exploration;    Granites;    Resource Development;    Fractures;    Basements;   

DOI  :  10.2172/891740
RP-ID  :  DOE/AL/68296
RP-ID  :  FC36-02AL68296
RP-ID  :  891740

美国|英语

来源: UNT Digital Library

【 摘 要 】

With financial support from the U.S. Department of Energy (DOE), Layman Energy Associates, Inc. (LEA) has completed a program of geothermal exploration at the Truckhaven area in Imperial County, California. The exploratory work conducted by LEA included the following activities: compilation of public domain resource data (wells, seismic data, geologic maps); detailed field geologic mapping at the project site; acquisition and interpretation of remote sensing imagery such as aerial and satellite photographs; acquisition, quality control and interpretation of gravity data; and acquisition, quality control and interpretation of resistivity data using state of the art magnetotelluric (MT) methods. The results of this exploratory program have allowed LEA to develop a structural and hydrologic interpretation of the Truckhaven geothermal resource which can be used to guide subsequent exploratory drilling and resource development. Of primary significance, is the identification of an 8 kilometer-long, WNW-trending zone of low resistivity associated with geothermal activity in nearby wells. The long axis of this low resistivity zone is inferred to mark a zone of faulting which likely provides the primary control on the distribution of geothermal resources in the Truckhaven area. Abundant cross-faults cutting the main WNW-trending zone in its western half may indicate elevated fracture permeability in this region, possibly associated with thermal upwelling and higher resource temperatures. Regional groundwater flow is inferred to push thermal fluids from west to east along the trend of the main low resistivity zone, with resource temperatures likely declining from west to east away from the inferred upwelling zone. Resistivity mapping and well data have also shown that within the WNW-trending low resistivity zone, the thickness of the Plio-Pleistocene sedimentary section above granite basement ranges from 1,900–2,600 meters. Well data indicates the lower part of this sedimentary section is sand-rich, suggesting good potential for a sediment-hosted geothermal reservoir in porous sands, similar to other fields in the region such as Heber and East Mesa. Sand porosity may remain higher in the eastern portion of the low resistivity zone. This is based on its location hydrologically downstream of the probable area of thermal upwelling, intense fracture development, and associated pore-filling hydrothermal mineral deposition to the west.