Abstract - Accurate evaluation of risk associated with hydrocarbon exploration in faulted areas requires a means of estimating the sealing capacities of faults bounding undrilled prospects. Currently used methods for estimating the sealing capacities in an exploration setting are empirical, and based on calibration of a fault seal parameter against known hydrocarbon column heights. Fault seal parameters are typically some function of fault displacement and the shale content of the faulted sequence. Fault seal capacities predicted by these methods are rarely incorporated into hydrocarbon migration models, although there are many advantages in doing so. Whether or not migration modelling incorporating predicted fault seal capacities can replicate the location, size and hydrocarbon phase of known accumulations provides a very stringent test of fault seal prediction techniques. In this study we incorporate fault seal capacities into a migration model of the Oseberg South area, Viking Graben. Several thousand realisations of the migration model, using different fault seal capacity predictors, are ranked by the accuracy of the match they achieve to the known oil-water contacts. Reasonable matches to the data are found for a limited range of fault seal capacity predictors. These results provide both a more robust estimate of fault seal capacity and a more accurate evaluation of uncertainty than methods currently applied.
Abstract of talk given to:
Irish Geological Research Meeting, Trinity College Dublin, February 2009.