Gas Blending for Miscible Gasfloods in South Oman

摘要

How to ensure that miscibility of oil and gas is achieved in each reservoir is a fundamental issue for miscible gasfloods involving different oil reservoirs with varying fluid properties. This paper reports on all the work done to help decide on how to optimally blend available gas such that miscibility can be achieved in all reservoirs with appropriate focus on the first reservoirs to be flooded. These studies have resulted in an investment decision to undertake a miscible gasflood already in 2005, whereas initial production from four reservoirs had only started in March 2004. Main components of this paper are: (1) Design of experiments for a wide spectrum of fluids (from near-critical systems to black oil systems) using miscible sour gas-blends while minimizing cost and the time spent on the experiments. (2) Acquisition, interpretation of the data (3) Utilization of the data for reservoir engineering/design calculations using a consistent approach for a cluster of sour reservoir fluids, (4) Recommendations based on the experimental data and calibrated simulation models.