Computer Modelling of Multiple Surfaces with Faults

RAVEN, HAN, Shell U.K. Exploration and Production, London, U.K., and NICK HOOPER, Radian Limited, Woking, U.K.

Today's increased processing capacity of computers makes it viable to improve the computer mapping of multiple surfaces with faults. Traditionally, in volumetric field models, faults are treated as vertical planes for each reservoir zone or throughout the reservoir. It is possible to produce grids of single faulted surfaces with realistic contours in the fault polygons, but until now no commercial mapping package has been able to routinely handle multiple horizons with faults.

Jointly, Shell U.K. Expro and Radian Corporation have developed a system with which the "automated" volumetric modelling of multiple horizons exhibiting nonvertical faulting is possible. The modelling is based on the construction of fault plane grids from fault traces and a set of attributes. These grids can be intersected with structural and isochore grids for each reservoir zone, realistically modelling the migrated fault polygons for each structural horizon. This greatly enhances the structural definition for volumetric analysis.

It is intended to expand the system with the options for the inputting of LANDMARK fault segment files and fault trace editing facilities. Both normal faults and listric faults can be modelled; other fault types will be added in the future. The grids may form the input for three-dimensional modelling software. The "Full Fault Modelling System" (FFMS) is a standalone module. It has been designed to work closely with Radian's CPS-3(trademark) Advanced Mapping Software, but can equally operate with any available computer mapping package. CPS-3(trademark) is a registered trademark of Radian Corporation.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)