Wellbore Model Inversion: Coupling of a Wellbore Simulator And An Inversion Software

Abstract

Modeling of two-phase fluid flow in a geothermal production well is one of the reservoir engineering techniques widely used to study well performance under different flowing conditions. As with other modeling techniques, it is a good practice to validate wellbore models by calibrating them against measured parameters such flowing temperature, pressure, velocity, and wellhead flow characteristics before it can be used for any prediction purposes. In this paper, an automated method of wellbore flow model calibration is demonstrated. The wellbore flow simulator Simgwel was used to model flow in a number of geothermal production wells and the inversion software PEST was coupled with the simulator to automate the calibration process. Reservoir pressure, feedzone enthalpies and productivities, and %NCG were identified as calibration parameters. The method proved to be very fast and effective when tested with several producing wells.