Feasibility of steam injection for three light oil reservoirs in different geologic settings has been evaluated. These were a waterflooded deltaic sandstone, a waterflooded vuggy dolomite, and a deltaic sandstone structural trap with a gas cap. Optimization of steam injection to take advantage of individual reservoir characteristics is demonstrated. For the deltaic sandstone, selective flooding of channel sands with upward fining porosity gave the best results. For the vuggy dolomite, a hybrid steamflood-steam stimulation process that maximizes conductive heating of bypassed oil was found to be best. For the structural trap, up-dip steam injection below the gas cap with down dip producers showed more recovery over gravity drainage. Sensitivities of each process to uncertainties in geologic and rock-fluid parameters were also investigated. The most influential parameters were identified for examining the quality of input data and the added value of information to reduce the uncertainties. Recent advances in reservoir characterization and modeling tools enable us to predict the performance of a Light Oil Steamflood (LOSF) more accurately than in the past, considering details of reservoir geology, fluid phase behavior, and displacement process physics. This is demonstrated through re-evaluation of a project carried out in 1985 in the Buena Vista Hills field in California where initial modeling using then current methods predicted a successful project. The re-evaluation would have correctly predicted failure as a result of early steam breakthrough. Results show that light oil steamfloods can be designed to take advantage of post-secondary oil saturation distribution. The resulting project may be carried out in a considerably different fashion than conventional heavy oil steamfloods.
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