--> Microstructural and Diagenetic Evolution of North Sea Fault Zones, by S. J. Haggerty; #90986 (1994).
[First Hit]

Datapages, Inc.Print this page

Abstract: Microstructural and Diagenetic Evolution of North Sea Previous HitFaultNext Hit Zones

Susan J. Haggerty

The deformation mechanisms and diagenetic events that determine the evolution of the fluid-flow properties of North Sea faults have been established by characterization of faults in core and thin section. The results of this study have implications for predicting Previous HitfaultNext Hit seal and Previous HitfaultNext Hit-migration potential.

Independent particulate flow allowed ductile smearing of sand and shale units in North Viking Grahen Previous HitfaultNext Hit zones via grain disaggregation and rotation. Cataclasis produced fine-grained Previous HitfaultNext Hit gouge in sand-rich lithologies in southern North Sea fields. The cataclasis has resulted in Previous HitfaultNext Hit cross-seal even where sand/sand juxtaposition occurs.

Capillary pressure measurements of the deformed samples indicate that both independent particulate flow and cataclastic deformation mechanisms result in relatively low-permeability Previous HitfaultNext Hit zones. Preliminary calculations using the capillary pressure results suggest, however, that faults with good sealing potential can allow hydrocarbon migration over geologic time scales.

Cements are commonly observed within the North Sea Previous HitfaultNext Hit zones; these cements also contribute to the observed permeability reduction. Current research will establish the relative and absolute timing of faulting and cementation to determine whether the cement precipitates as a result of focused fluid flow during Previous HitfaultNext Hit activity, or after Previous HitfaultTop movement.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994