Modern Reservoir Engineering: A Simulation Approach

"The initial reservoir model is the engineer's best estimate of the geometrical configuration, rock and fluid properties and the flow mechanics of the reservoir system but hardly ever this first model is adequate for fluid recovery prediction. Before reliable forecasts can be done, it is necessary to alter the input data (the reservoir model) to the reservoir simulator until a reasonable approximation between the output and the observed (historical) data is achieved (Crichlow, 1977). "