Optimal and Coordinated Functioning of Oil and Gas Wells

Typical production objectives in the lift gas assisted oil wells include stable and optimal production that meets demands on oil and gas. The attainment of these objectives in a typical production facility involving depletion of oil and gas, from a diversity of reservoirs that have different pressures, compositions, gas to oil ratios and natural flows. The objectives are also bound by constraints on compression and its costs, specifications on the export gas for pressure, volume and composition as per different customer end demands. While optimal allocation of the limited lift gas is desirable, an enterprise-wide, coordinated view of the production from the diverse gas or oil reservoirs would facilitate greater flexibility towards meeting the customer demands in an optimal manner. In this paper, we consider a smaller prototype of a production facility involving a low pressure, medium pressure and high pressure gas reservoirs, which also exhibit varying compositions, gas to oil ratios and natural flows. We propose a formulation that promotes co-ordination between these diverse reservoirs so as to honor the constraints on export gas or liquid pressures, compositions or natural flows. The results have been verified on a prototype of a three well production facility using a simulation model adapted from Jahanshahi et al. (2012).