Abstract

There have been 248 giant fields (>500 MMBOE) found since 2000. Information gleaned from studying these giant fields’ data has shown that the industry has undergone at least five major paradigm shifts in the past 20 years.

First, unconventional and tight gas exploration has transformed the industry. It is expanding to South America, Oman, Bahrain, China, and other countries.

Second, creaming curves show step changes in success in finding giant combination and stratigraphic traps. These traps now comprise 60% of the volumes, up from 10% to 15% historically, and attributed to improved seismic imaging. The most important trends are salt-sealed carbonate reef complexes in the Caspian Basin, Egypt, Brazil, and Turkmenistan. Of equal importance are passive margin turbidites, commonly de-risked with amplitude vs. offset (AVO) and 3-D seismic reservoir imaging.

Third, ultra-deep drilling to 5–9 km below mudline is finding oil, rich liquids, and porosity. Some of this can be explained by lowered geothermal gradients beneath thick salt, but other oils occur at temperatures of 160°C–180°C with very high pressures. We discuss new concepts to explain these deep liquids from the standpoint of pressure, volume, temperature (PVT) data and fractionization during migration.

Fourth, giant fields have been found overlying oceanic crust, breaking a long-held paradigm that these kinds of plays do not work.

Last, deep, overpressured upward hydrodynamic flow and tilted hydrocarbon contacts have been documented in many basins. This may ultimately turn out to be more of a “norm” than an exception.