Regional geopressure studies — Their impact from prospect identification and risking through the life cycle of a field to production and development

Abstract

Regional data provided geologic and hydraulic context to help understand the aspects of the petroleum system in a basin to help companies derisk and reduce uncertainty in potential acreage. Supplementing local data, which often can be limited or absent, with an understanding from a regional geopressure perspective can mean the difference between success and failure. A similar concept of regional assessment and the importance for reducing uncertainties is introduced, except focused only on geopressure and its implications and uses across the entire oil-field cycle. These studies synthesize stratigraphic, structural, and basin-history data to produce an understanding of mechanisms of pore-pressure generation and its resultant distribution across a basin. The results of these regional assessments of pressure have the following benefits: Rock-physics models are better understood at the prospect-identification stage once the pressure regime is understood; an understanding is gained of the risk of hydraulic top seal failure, i.e., seal breach within a license acreage; well planning can be more accurate because all geologic uncertainty, not visible on local seismic, can be anticipated; real-time data can be reconciled with data within a regional study to better define pressure-transition zones; in production, naturally draining, connected dynamic reservoirs can be identified only by regional overpressure mapping; in true frontier areas, a regional study of deep water, for instance, from an entirely different basin, provides a sense-check analogue of the local pressure regime estimated from the seismic velocity for a new prospect.