Play Fairway Mapping
Play fairway mapping has been used successfully to evaluate the remaining hydrocarbon potential of basins in the Northwest Europe offshore region. It provides a consistent view of their potential and helps companies to develop exploration portfolios that balance risk, prospect size and acreage availability.
It’s the combination of regional and local geological parameters that controls the location of a hydrocarbon accumulation. Primary regional parameters, which can be mapped throughout a basin, are reservoir, topseal and hydrocarbon charge. Local parameters that affect prospectivity are trapping and the presence or effectiveness of topseal and reservoir. The play fairway approach relies on mapping individual plays at regional rather than local scale.
The potential of any play can be evaluated from its fairway map, which overlays the distributions of regional parameters for that play. The area of maximum prospectivity (or ‘play fairway’) is outlined and risks can be estimated. For the play fairway itself, the risk is low or non-existent, but it increases outside the fairway if one or more regional parameters are unfavourable. The degree of confidence which can be felt about this regional risk is related to lack of data, poor database quality and an uncertain geological model. It varies significantly for mature, immature and frontier basins, and between plays within the same basin so it’s essential that it’s assessed in a consistent way to make useful objective comparisons between different types of play and basin.
Mapping allows exploration effort to be focused play by play in the most prospective areas of a basin. In the North Sea it’s an excellent tool for screening and ranking acreage. By assessing the prospectivity of individual blocks, it removes a significant amount of exploration risk. In immature and frontier basins, it helps to qualify risk associated with reservoir and hydrocarbon charge.
Many companies are now gathering their exploration data together in a GIS database. In response to this, all the Ternan reports will soon be available in this format,improving the exploration workflow by offering the ability to view, for instance, the play fairway or reservoir distribution in combination with seismic coverage over areas of interest.