Palaeo-Fault Analysis: Defining the Evolution and Impact of Faults Through Time

Abstract

Quantitative fault analysis is based on the principle that faults develop in three-dimensional space in a predictable way. Evaluating the results of this analysis can rapidly highlight interpretation errors and complexities related to fault evolution; both of which can have important implications when considering the economic significance of a fault (e.g. sealing capacity). The techniques and theories associated with fault analysis are primarily derived from detailed coal-mine mapping in the mid-1980s (e.g. Watterson, 1986) but today are most frequently applied to geological models built from high-resolution 3D seismic reflection data. Despite the prevalence of detailed structural models, previous work has focused on static models with limited integration of established restoration techniques and displacement-based fault analysis. While enabling definition of present-day geometries and across-fault relationships, static analysis provides minimal insight into the characteristics of a fault during its evolution. Here, we demonstrate how sequential backstripping and fault restoration using industry standard compaction curves, allows realistic implementation of palaeo-fault and seal analysis. By accounting for compaction and displacement, the true development of faults can be quantified allowing across-fault relationships and geometries to be defined at key time-steps, for instance at the time of hydrocarbon migration and trapping. The integration of these workflows is illustrated with examples of faults from areas under active hydrocarbon exploration.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016