Coso Geothermal Area, China Lake, California

Coso Reservoir Injection and Water Extraction Project-Analysis

Client: MHA-RMT Inc. and Inyo County
Geologica Geothermal Group is working on three different projects related to the development of the Coso Geothermal Field, a liquid-dominated geothermal resource located in eastern California which has produced up to 265 MW annually since the mid-1980s. This field has experienced production-induced pressure drawdown and is planning to pump local groundwater to inject into the reservoir. Geologica Geothermal Group is performing an analysis of the benefit of injection, numerical simulation of the potential impacts of groundwater extraction and an evaluation of the potential geochemical and hydrological effects of increased injection on surface manifestations. In addition, Geologica Geothermal Group is preparing annual Coso Monitoring Program Reports for the U.S. Navy Geothermal Program Office (GPO) presenting hydrological, chemical, Geologica Geothermal Group and geophysical data that has been collected at Coso Hot Springs and related surrounding areas. These reports are part of the Coso Hot Springs Monitoring Program which is part of a 1979 agreement by the GPO to document changes in the physical and chemical characteristics of the Coso Hot Spring Archeological District. The data includes steam flow and groundwater levels from selected wells, physical measurements from fumaroles and mud pots, fluid chemistry for select samples, photographic documentation, local meteorological data, and for the latter two years, seismological data. Tasks included database management, data analysis, data evaluation, graphics, and reporting in conjunction with GPO staff. Geologica Geothermal Group is also performing an analysis of geochemical data collected from Coso geothermal production wells. The objective of this work is to optimize the resource development. Geologica Geothermal Group is applying existing and new tools for the interpretation of geochemical data for purposes of understanding the subsurface conditions in the Coso Geothermal reservoir. In addition, we develop and maintain GIS and database to: organize the data in a system that allows for the QA/QC of the data, transform steam +/- brine analyses into reservoir fluid chemistry under single or two-phase conditions, provide temporal and spatial analysis of the available geochemical data across the field and in individual wells over time, compare geochemical and related well production data, as well as organized data for additional interpretation. Results are reported annually.