The Hall Plot Analysis of a Water Injection Test Affected by Geothermal Reservoir Response

Abstract

Water injectivity into geothermal reservoirs is discerned by water injection tests conducted in injection wells and may continue for weeks. The evolution of an injectivity test and the responsive variations in reservoir properties may be ascertained by the steady-state Hall-plot analysis. Thus the efficiency of injectivity may be evaluated by such analysis method, in a continuous manner.
A variable-rate and long-term water injection test, that was conducted in a reinjection well in Kizildere geothermal field, was attempted to be assessed by the Hall plot analysis. The presence of free carbon dioxide gas, prior to the commencement of water injection, is claimed to be detected in the reservoir. At a certain stage in injection operation, the reservoir fill-up and subsequent dissolution of free carbon dioxide in water are also recognized.