Three-dimensional simulation of 1/8 of confined 5- and 9-spot patterns

The authors present modifiers for transmissibilities, block volume, production (injection) rate and productivity (injectivity) index constant to properly describe boundary blocks in 1/8 of a confined 5-spot and 9-spot flood patterns in three dimensions for a simulator which operates on block-centered grid points. These modifiers have theoretical basis and possess potential for use in practical field applications of reservoir simulation. The modifiers are tabulated and can be easily applied by the practicing engineer. The authors also investigates the validity of a commonly used 1/8 of a confined 5-spot pattern where the apex cells at the three corners are combined with blocks adjoining them. It is found that the simulation of 1/8 of a confined pattern is an order of magnitude cost efficient over that of a 1/4 or 1/2 pattern while producing exactly the same performance for the whole pattern, while the use of the commonly used 1/8 of a confined pattern does not produce the performance for the whole pattern.