[First Hit]

Datapages, Inc.Print this page

Previous HitFaultNext Hit Analysis and Previous HitFaultNext Hit Seal

Tim Needham, Graham Yielding, Brett Freeman

Hydrocarbon reservoirs are often separated into compartments by sealing faults. Faults act as seals either by juxtaposition of reservoir intervals with sealing lithologies or by the sealing properties of the Previous HitfaultNext Hit surface itself. It is possible to analyse juxtaposition sealing by the construction of 'Allan' Previous HitfaultNext Hit-plane diagrams. Refined versions of these diagrams can be produced by optimising the Previous HitfaultNext Hit interpretation. The extent of the Previous HitfaultNext Hit surface can be determined by displacement analysis and the position of tips and splays identified. Horizon cut-offs can be accurately positioned by the use of an algorithm which 'snaps' the horizons on to the Previous HitfaultNext Hit surface. The Previous HitfaultNext Hit surface can also be modelled so that topographic variations in the surface are incorporated into the f nal diagram. Detailed reservoir stratigraphy can be added between seismic markers so that areas of cross-Previous HitfaultNext Hit communication can be identified.

The ability of the Previous HitfaultNext Hit surface itself to act as a seal is a function of the displacement at any point on the Previous HitfaultNext Hit surface and the lithology of the units displaced past that point. Using the displacement mapped on the Previous HitfaultTop surface, in conjunction with lithological information it is possible to calculate the potential for sealing by clay smear at any point. By careful calibration using well test and production data it is possible to use the clay smear estimates to predict the likely behaviour of faults bounding undrilled compartments.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995