Heterogeneidades estruturais em reservatorios : geometria e distribuição de falhas

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

This work aims to characterize at oil field and outcrop scales faults as structural heterogeneities in reservoirs. Their impact on oil exploitation is very important, specially upon rift basin oil fields. Recently, this kind ofheterogeneity has been object of great interest in reservoir characterization. A case study carried out on a structurally complex oil field led to the conclusion that faults produce strongly compartmentalized reservoirs. Fault displacements between 20 and 500m constitute seals and produce hydrocarbon traps. Statistical studies showed that fault displacement smaller than 40m are undersampled due to lack of resolution. The real amount of small faults is probably greater than that observed, and they may be responsible for petroleum reserves yet to be discovered in the field. The limited resolution of fault detection methods and the strongly interpretative aspect of fault correlation deteriorate the original statistical distribution of fault size and spacing. Photomosaics interpretation and field works carried out on a fluvial sandstone outcrop severely affected by normal faults resulted in detailed structural heterogeneities maps. On this scale, the fractal relation for fault size distribution and the clustered aspect of faults were obtained. Several features associated to soft-sediment faulting were recognized, such as shale smears that form barriers which can compartmentalize reservoirs

ASSUNTO(S)

reservatorios geologia estrutural

ACESSO AO ARTIGO

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