Assessment of favourability of oil and gas discoveries in the plays of the Norwegian Sea

Mapping favourability for oil and gas discoveries by integrating diverse geoscience datasets have been attempted by the use of systematic weighting of geologic factors. A recently published Bayesian weighting methodology (Rostirolla et al. 2003) has been used in the Norwegian Sea to quantify the favourability for the existence of new oil and gas fields. The methodology for delineating favourable areas is based upon a cell-by-cell basis where GIS is used to express different geologic factors as present or absent. Later the cells are weighted and probabilistically combined to form a favourability map. This study from the Norwegian Sea involves extensive use of GIS to compute influence zones that relate faults and structural boundaries to producible quantities of hydrocarbons. The petroleum system data are organized in descriptive models and analyzed against drilling results. The characterization of the estimated favourable areas is later verified against the existing discoveries in a training area in order to evaluate the remaining potential of oil and gas in target areas. The study show that statistical distributions based on geologic features can be used to map zones favourable for new discoveries and may help a company to allocate exploration effort to a region.