| Abstract |
Water injection into a vapor-dominated geothermal reservoir is an effective method of sustaining steam production fiom the jeld. Injection puts additional water to the reservoir and raises the prevailing reservoir pressure. This process improves the fieldÆs productivity. However, the increased pressure also increases the water retention capacity of the reservoir rocks through the effects of adorption and capillary condensation. Due to the sign9cant costs associated wirh water injection programs, optimizing injection not only involves maximizing the energy yield fiom the resource but also the present worth of the project. Two crucial parameters that need to be established are: I) how much to inject; and, 2) when to inject it. This study investigated the optimaI design of these parameters. It was found that compnrabIe energy yield can be attained for injection programs that are initiated ar various stages of the fieldÆs development. Higher injection rates are desirable when the injection program starts later in the productive lijie of thejeld. Considering the economics of the project, it is best to implement the injection program during the later stages of the fieldÆs development. This way, a greater fiaction of the injectate can become available for production and at the same time optimize the present worth of the project. |