| Abstract |
Several types of geothermal systems exist in nature but only hydrothermal convective systems are being exploited at the present time because of their proximity to the earth's surface and their amenability to utilization. Among the geothermal systems discovered to date, hot water systems are perhaps twenty times as common as vapor dominated systems (Muffler and White, 1972). In general, large volumes of geothermal liquids are produced for economic heat extraction. Such large scale production of geothermal fluids should generally be expected to cause significant reductions in pore fluid pressures leading to appreciable rock deformations and displacement at or near, the ground surface. This phenomenon has already been observed over the Wairakei and Broadlands geothermal fields of New Zealand ( Stilwell, et al., 1975 and Otway, 1976). Since ground displacements may, affect engineering structures related or unrelated to the operation of the geothermal field, it is important to be able to predict the pattern and magnitude of the deformations that may resiilt from fluid production so that appropriate ameliorative actions may be taken in advance. |