We report Li isotopic measurements in seawater derived waters discharged from geothermal wells, thermal and submarine springs located in volcanic island arc areas in Guadeloupe (the Bouillante geothermal field) and Martinique (Lamentin plain and the Diamant areas). The lithium isotopic signatures of the geothermal fluids collected from deep reservoirs are homogeneous for a given site. However, ...

system at Coso. This investigation is Part of an ongoing study being perCos0 is one of several high-tempeformed through an agreement betwen rature geothermal systems associated California Energy Company and the Earth with recent volcanic activity in the Science Laboratory Division/university Basin and Range province. Within this of Utah Research Institute. fracture-dominatedsystem, temperatnres...

A series of fossil spring deposits are exposed along the Dixie Valley fault just south of the producing geothermal field, in an area now characterized by active fumaroles and steaming ground. These deposits are composed of both travertine and sinter that have trapped pollen and other plant material during their formation. Radiocarbon dates on the organic material indicate that the youngest hot ...

The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties...

Recent national focus on the value of increasing US supplies of indigenous renewable energy underscores the need for re-evaluating all alternatives, particularly those that are large and well distributed nationally. A panel was assembled in September 2005 to evaluate the technical and economic feasibility of geothermal becoming a major supplier of primary energy for US base-load generation capa...

To determine factors controlling permeability variations within and adjacent to a fault-hosted geothermal reservoir at Dixie Valley, Nevada, we conducted borehole televiewer observations of wellbore failure (breakouts and cooling cracks) together with hydraulic fracturing stress measurements in six wells drilled into the Stillwater fault zone at depths of 2-3 km. Measurements in highly permeabl...

This paper reviews geophysical and seismological imaging in the Coso geothermal field, located in southeast-central California. The Coso geothermal production area covers 6 10 km. Although regional seismicity is addressed, as it sheds light on the magma, or heat, sources in the field, the primary focus of this paper is on the main production area. Three-dimensional inversions for Pand S-wave ve...

s and Conference Proceedings Segall, P. and J.R. Rice, Dilatancy, compaction, and slip instability of a fluid-infiltrated fault, EOS. Transactions, American Geophysical Union, Vol. 75, No. 44, p. 425,1994. MOSSOP, Antony, and P. Segall. Induced seismicity at The Geysers, Northern California (EOS, TRANSACTIONS, AMERICAN GEOPHYSICAL UNION ; Vol. 75, No. 44, Suppl., p. 444, 1994). MOSSOP, Antony. ...

AEiSTRACT Reinjection of spent geothermal brine is a common means of disposing of geothermal effluents and maintaining reservoir pressures. Contrary to the predictions of twefluid models (tweviscosity) of nonisothermal injection, an increase of injectivity, with continued injection, is often observed. Injectivity enhancement and thermally-affected pressure transients are particularly apparent i...

We analyze statistical features of background and clustered subpopulations of earthquakes in different regions in an effort to distinguish between human-induced and natural seismicity. Analysis of end-member areas known to be dominated by humaninduced earthquakes (The Geyser geothermal field in northern California and TauTona gold mine in South Africa) and regular tectonic activity (the San Jac...