Reservoir management decision-making in the presence of geological uncertainty.

摘要

The investments to develop a reservoir are very large, so any improvement in the development plan could represent millions of dollars in additional profit. However, the decisions about the development plan are made in the presence of many sources of uncertainty. Geological uncertainty about the reservoir geometry and petrophysical properties, due to sparse sampling of the reservoir, is one of the uncertainties that could influence the reservoir management decisions significantly.; This work introduces a so called Full approach to incorporate the geological uncertainty in the selection of the best production scenario among a set of predefined scenarios. This approach utilizes multiple geostatistical realizations and presents the advantage of including the profit seeking and risk aversion profile of the company.; To address problems involving well locations, this work introduces the concept of a quality map. This map is used within the Full approach to decide on the best number of wells with the corresponding optimized spatial configuration. An L-optimal quality map, obtained by averaging individual realization quality maps through a loss function, allows locating the wells accounting for the geological uncertainty.; The quality map is built from flow simulations and integrates all the three-dimensional geological and fluid variables into a single two-dimensional characterization of the reservoir. Besides well locations, this two-dimensional characterization of the flow responses can be used to visualize productivity areas, to rank realizations, to identify a most representative realization and to compare different reservoirs.; Fifty synthetic yet realistic reservoirs and more than 450,000 flow simulations were generated in the course of this work to develop and evaluate the potentials of the Full approach and quality map.