| Abstract |
Injection testing is one of the required tests after well completion and, as the name implies, used to estimate the injection capacity of a well. The injection test data could also be used to determine the connectivity of injected wells to nearby producers by monitoring the behavior of surrounding wells during the injection test. At the steam-dominated Darajat geothermal field, these monitoring activities during injection tests include observing the trends of Non-Condensable Gas (NCG in wt%), boron (ppm), superheat (°C), Flowing Well Head Pressure (FWHP in barg), flow rate (kg/s) and micro-seismicity. A case study of the Well B-2 injection test showed an obvious impact on a particular production well. The condensate was injected in Well B-2 at a rate of ~45 L/s for 18 days. The specific monitoring wells were selected based on their connectivity to injector Well B-1, located at the same pad as Well B-2, as defined by the 2008 tracer test results. The injected tracer at Well B-1 is migrating along the Cibeureum Fault and appearing in production wells at the southwestern part of the Darajat reservoir. Well C-1, located southwest of Well B-2, showed an increase in NCG concentration during the injection test but returned to normal levels within two weeks after condensate injection was stopped. There were no detrimental changes in the steam deliverability of Well C-1 and other surrounding wells both during and after the injection test. However, this observation confirmed the connectivity between Pad B and fluid migration towards the southwest part of the field. |