The Connectivity and Conductivity of Overlapping Sand Bodies

Many oil reservoirs have a highly complicated geometry owing to the complex environment in which the sands were deposited. There is usually a mixture of good (that is, high-permeability) sandstones and poorer (low-permeability) siltstones, mudstones and shales. The main flow of oil during recovery is through the sandstones, the flow rates through the poorer rocks being too slow to be of economic consequence. Clearly, the connectivity of the sandstones is of prime importance in determining how much oil is potentially recoverable with a particular well configuration The overall shape of the connected sandstone is also important in determining the flow rates in the reservoir, through tortuosity effects, for example.