Abstract
We present an application framework that automatically identifies an optimal field development plan (FDP) for unconventional shale gas and tight oil fields. The proposed FDP comprises wells, surface locations (such as pads), well completion locations, and the drilling schedule. A suite of high-speed computational components allows generation of an FDP in minutes. Different development strategies can therefore be rapidly investigated.
The FDP is optimized using a trial-based optimization framework. During a trial, FDPs proposed by the optimizer in previous trials are extrapolated to propose a new FDP. This new proposed FDP must satisfy a wide range of geometric, operational, contractual, and legal constraints on the surface as well as in the overburden and reservoir. When a feasible FDP is identified, the production forecast is calculated using decline curves from type (or representative) wells, a high-speed semianalytical reservoir simulator, or a numerical simulator. This optimization framework supports a variety of objective functions, including recovery, net present value, return on investment, and profitability index. Optimization in the presence of subsurface uncertainty is also possible by considering an ensemble of reservoir models. A proposed FDP will then have a forecast value with an associated uncertainty. For a specified aversion to risk, a conservative or risk neutral FDP can then be optimized.
