Model study of historical injection in the southeast Geysers

A three component model study of the historical injection of two wells in the Unit 13 area demonstrates that the recovery of injection derived steam is influenced by the geologic structure of the bottom of the reservoir and the relative location of injection wells. The migration of injectate from the first injection well, located up structure from the second, quenched the area around the second injector before it started operation. While both wells had similar cumulative mass injected, nearly five times more injection derived steam is recovered from the first injector than the-second. Sensitivity runs were made to three cases of increasing matrix capillary pressure. The recovery of injection derived steam increases with higher values of capillarity. The interaction of structure at the bottom of the reservoir, injection well locations, and matrix capillarity all influence the recovery efficiency of injected as steam. The model developed in this study will be used to evaluate injection strategies at The Geysers