The Effects of Faulting on Production form a Shallow Marine Reservoir - A Study of the Relative Importance of Fault Parameters

Abstract

Abstract This paper describes a sensitivity study in which a variety of fault patterns was superimposed on a set of realistic heterogeneous sedimentary models of a near-shore marine environment. Using an experimental design technique, 32 faulted models were upscaled to a 40 acre (420m) water flood from which recoveries at water breakthrough and 1 MPVI were estimated by flow simulation. Statistical analysis of these data allowed us to study the relative effects of the various fault pattern parameters. We also studied the effects of adding faults to the same set of unfaulted reservoir descriptions. In summary, fault plane seal was found to be the most important fault plane seal was found to be the most important fault parameter influencing recovery at water breakthrough. Recovery at 1 MPVI was influenced by cross fault presence and fault plane seal. The stacastic noise in the modeled recoveries was increased significantly when faults were added. The influence of the sedimentary parameters was not eliminated by the addition of faults, although some significant reductions did occur for recoveries at 1 MPVI. An important effect appears to be the reduction in sweep efficiency when injector wells are placed near to sealing faults. Conversely, in layered (hydraulically sealed) sedimentary models, faulting can increase recovery by improving cross communication. P. 279