||Reservoir characterization, well behaviors monitoring and analysis, and forecast of production and injection are the keys reservoir evaluation conducted routinely in the process of managing and optimizing geothermal steam field power production. Wellbore simulation has been one of the main techniques applied by reservoir engineer to support their works. The capability of reservoir engineer to perform their analysis is however limited by how far the wellbore simulator can support their work. This paper described a new generation of wellbore simulator JIWAFLow developed by AILIMA. To support evaluations during field exploration and operations, JIWAFow has been built with capabilities to perform a complete reservoir engineering analysis from permeabilities characterization, well behavior monitoring, production and injection decline analysis, to steam supply and injection capacity forecasting. To honor reservoir uncertainties, JIWAFlow is also coupled with MONTE CARLO simulation to allow probabilistic calculation. JIWAFlow has been developed to make analysis much more time and cost efficient, robust and meet business requirements. JIWAFlow allows cloud computation and is integrated with web-based JIWA applications to perform seamless connection with geosciences, reservoir engineering, and surface monitoring data.