Assessment of production strategies of a gas condensate field using a black oil simulator: a case study

Parlaktuna, Burak
Condensates are low-density liquids that are produced along with the gas phase from wet gas or gas-condensate reservoirs. Availability of these liquids makes gas-condensate reservoirs more profitable than the other gas reservoirs since condensates are gasoline like fluids with API gravities more than 45°. Although the condensate production is profitable, the management of gas-condensate reservoirs is challenging. Due to their nature, condensates condense and separate from the gas if the pressure drops below the dew point pressure. The condensation causes an increase in the amount of liquid drop-out especially around the wellbores where the maximum pressure drop occurs. The condensates around the wellbores decreases or even blocks the flow of gas into the wells due relative permeability effects. Therefore it is required to prevent condensation in the reservoir which can be done by keeping the reservoir pressure high. On the other hand, bottom hole well pressures should be low enough to have a good production rate. This dissertation aims to assess different production and injection strategies and find out the optimal one by constructing static and dynamic reservoir models and simulate the production strategies for 50 more years in addition to the 45 years of production history of a South Caspian Basin field. The starting point of this study is to construct a static model based on an existing reservoir which consist of three blocks with eleven producing layers. The required fluid model is obtained using available fluid properties by the help of a compositional PVT equation of state software prior the preparation of dynamic or flow model. The production history of the field is used to construct a base for the simulations. The volumetric calculations are compared with the available data. Different production scenarios are applied including production at different rates, injection of water and gas separately and simultaneously as well. It was observed that keeping the pressure high with water injection in the reservoir but using the driving force of gas at the same time leads the minimum amount of liquid drop-out in the reservoir.
Citation Formats
B. Parlaktuna, “Assessment of production strategies of a gas condensate field using a black oil simulator: a case study,” M.S. - Master of Science, Middle East Technical University, 2015.