Integrated Seismic Studies At The Rye Patch Geothermal Reservoir, Nevada
Book: Integrated Seismic Studies At The Rye Patch Geothermal Reservoir, Nevada
AbstractA 3-D surface seismic reflection survey, covering an area of over 3 square miles, was conducted at the Rye Patch geothermal reservoir (Nevada) to explore the structural features that may control geothermal production in the area. In addition to the surface sources and receivers, a high-temperature three-component seismometer was deployed in a borehole at a depth of 3900 ft within the basement below the reservoir, which recorded the waves generated by all surface sources. A total of 1959 first-arrival travel times were determined out of 2134 possible traces. Two-dimensional ray tracing was performed to simulate wave propagation from the surface sources to the receiver at depth. Travel time differences between observed and calculated times were mapped to topographic changes in the elevation of the interface between the carbonate basement and the sedimentary and volcanic unit above. Results indicate the presence of two dominant geologic features. The first confirms the regional trend of the geologic units in the Basin and Range province with a north-south strike and dip to the west, as expected for normal faulting encountered in an extensional regime. The second is a local disturbance of this regional pattern in form of an elevation of the interface between the carbonate basement and the overlying sedimentary sequence, striking east-west. The geometry of the structure is corroborated by results from a seismic-reflection survey, and by results of tomographic studies conducted as part of the seismic survey. Seismic waves, generated from far-offset shots during the 3-D surface survey, exhibit a sudden decrease in amplitudes while propagating across the boundaries of the elevation high. This apparent boundary correlates spatially with the location of the Rye Patch fault as interpreted from the 3-D seismic reflection data. Finite-difference modeling of elastic wave propagation is performed to estimate the structural parameters of the fault. Questions to be answered are fault width, strike, dip, and strength, to make inferences about the nature of the fault and the geologic process that could have formed
- Roland Gritto, T. M. Daley and E. L. Majer
- Geothermal Technologies Legacy Collection, Date Not Provided
- Not Provided
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Roland Gritto,T. M. Daley,E. L. Majer. . Integrated Seismic Studies At The Rye Patch Geothermal Reservoir, Nevada. (!) : Geothermal Technologies Legacy Collection. (!) p.