World-wide deep water exploration and production: past, present and future

Pettingill, H. S., Repsol YPF, Madrid, Spain, and Paul Weimer, University of Colorado, Boulder, Colorado

Abstract

Deep water (>500m) is an immature frontier, with approximately 50 BBOE discovered, over half since 1995. Only about 20% of these resources are developed and less than 5% have been produced. Most reserves have been found in the Gulf of Mexico, Brazil, and West Africa. Ninety percent are in turbidites, primarily of Tertiary age. Conservative estimates for deep water reserves remaining to be found are 100-150 BBOE. The global deep water success rate was about 10% until 1985, but has since averaged approximately 30%, driven by remarkable success in the Gulf of Mexico and West Africa. Whereas the world-wide discovery of giants has fallen off in recent decades, the discovery rate of deep water giants is rapidly increasing.

Most current deep water hotspots and reserves are located along passive margins, downdip from productive Tertiary delta systems, in depocenters confined by mobile substrate. A key success factor is "high kH" reservoirs (high flow rate and well ultimate). These commonly occur within ponded minibasins associated with mobile substrate, where stacked turbidites result in high net pay per area. Other key exploration success factors have been seismic DHI’s and improved reservoir architecture prediction. Leading companies are moving into non-DHI plays and other geologic settings, including pre-Tertiary objectives and areas lacking major updip reserves.

Recent trends suggest several themes for future deep water exploration. The first is a continuation of established plays, which are still at an immature stage of drilling. The second is going beyond the established formula to basins lacking updip production, unconfined basins, compressive margins, and pre-Tertiary and non-turbidite targets. The third theme is increased gas exploration, as pipeline networks and liquefaction technology advance in conjunction with increased consumption. Going deeper constitutes the fourth theme, both ultra-deep water and deeper drilling depth, including subsalt, sub-detachment, and sub-volcanic targets. The fifth and final theme focuses on new business opportunities, which may arise in areas currently not open due to government monopolies, moratoriums, and boundary disputes.