ABSTRACT
The production history of a one thousand well field extension drilled in the early 1980's showed that additional wells could not be drilled at current oil prices and oil recovery. Step out drilling and production history showed that an additional one hundred infill and development wells could be drilled if the recovery could be increased. Multiple production logs indicated the upper half of the zone was not open at the well bore. Thus, if the upper zone could be more effectively completed, the well recovery had the potential to be increased to a level where future development would be feasible. The low reservoir pressure and high permeability contrast requirements demanded that a much higher viscosity fluid system needed to be used that also had the ability to clean up easily. The nitrogen foam frac yielded these desired characteristics. Five infill wells were drilled in 1991 and 1993 utilizing a nitrogen foam frac system. Production from the wells has shown a projected ultimate recovery from the wells of approximately twice the original wells.
