Super Basins…The Oily Places
....By Brian Horn...Recently IHS Market developed the idea of a Super Basin as a basin that has produced over 5 billion barrels of oil equivalent (BBOE) and has an additional 5 BBOE in remaining reserves. We all are familiar with many of these places: Gulf of Mexico, Permian Basin, North Sea, Offshore Nigeria, Arabian basins, Alaska North Slope. The continued search for additional hydrocarbon resources has resulted in many innovations, changes in technology, leaps in geologic understanding and improvement in the exploration process resulting in the US producing over 10 million barrels of oil daily, the largest in any time in the history of the industry. The unconventional revolution is now conventional and has become a dominant method of exploration and exploitation of hydrocarbon resources in North America. While technology continues to provide new access to what once were uneconomic hydrocarbon accumulations, much of this activity is focused on what are generally considered mature basins.
When I worked in new ventures I remember a comment made byIann Vann (EVP Exploration at BP), “if you want to find oil, you must look in the oily places.” At first glance this seemed to be simplistic, of course, you find oil in oily places. In the years that have followed, I have come to understand the insight and value of these words and the truth of these words is what makes a Super Basin. We find oil in oily places and we will continue to find more oil in oily places. Super Basins are unique places on the earth and as technology progresses the industry will continue to unlock the ultimate potential of present and future oily places.
Old Place – New Ideas
In 1958, Parke Dickey wrote, “We usually find oil in a new place with old ideas. Sometimes, we find oil in an old place with a new idea, but we seldom find much oil in an old place with an old idea.” This is more applicable today than ever before. The caveat I would add is that when the old place is a Super Basin, the industry has probably not discovered the full potential of that area due to the application of limited technology or ideas.
A major cause of the continual rejuvenation of many mature basins has been the ability of seismic data to provide a better image of the subsurface geometry, lithology and the ability to understand basin evolution through time. Long-record, long-offset data provide a better image of the deepest parts of a basin. Multi-azimuth data enable attribute analysis to better predict fluid types, rock propertiesand fracture orientation. The development of drilling and completion technologies has changed the conventional idea of reservoir rock quality. Our understanding of petroleum systems and prediction of fluid type variability across a basin provides new ways to drill and complete a multitude of reservoirs and begin to better understand the interplay of lithology/petrophysics, fluids, pore space, rock physics, pore pressure and geomechanical properties in the subsurface.
Looking for the Next Super Basin
What are the new ideas that will unlock emerging basins and ultimately add to the Super Basin category? The following is a short list that comes to mind:
1. Fiscal Terms will be the biggest driver for continued exploration. High production takes by NOCs or governments, taxation or regulation are impediments to continued drilling and future exploration growth.
2. Understanding a Basin from the bottom up is an integral part of the exploration process and provides the ability to understand the basin in a regional framework and provides a basis for high-grading new areas. In many North American basins where drilling activity is high, the regional framework is based on the abundance ofwell control and is a benefit to working a mature basin. Alternatively, the depth to drilling also can function as a barrier to understanding the deeper potential in a basin and often bias current paradigms or conventional wisdom with respect to a deeper play.
A Quality Database – the fidelity of a subsurface database (well logs, stratigraphic correlation, seismic data, and production/pressure data) is perhaps the most critical aspectfor future exploration activity and success. Any exploration geoscientist knows that unless the database in an area is consistent, accurate and easily accessible the exploration process will be slowed and play concepts and drillable prospects will have a greater uncertainty. The seasoned explorationist will have the patience to sift through mountains of data to find nuggets of insight that can support a new play
1. Improved Seismic Imaging – The ability of high-speed computing and data storage has led to the creation of large 3D data sets (50-80,000 km2). These legacy data acquired over the past twenty-five years from multiple different surveys can add significant value at a much lower price point. Development in seismic processing algorithms such as reverse time migration (RTM) and full waveform inversion (FWI)have enabled companies to reprocess legacy seismic data acquired with various parameters to be merged and reprocessed creating new fit-for-purpose 3D data that provide a product that is comparable to many modern wide azimuth surveys that are cost-efficient.
2. Geologic Ideas/Innovation – regional evaluations and analysis in offshore exploration rely primarily on seismic data and the development of play fairway concepts. Reconstructing the conjugate margins of what was a single basin, correlations from source to sink can provide insight and ideas. The recent discoveries along the transform margin of Africa in Ghana are a great example of a play type that has been extended to the conjugate margin as evidenced by the major discoveries in offshore South America. Understanding similarities and differences in analogous play types around the world will continue to be a key factor in changing emerging basins with significant discoveries into the next Super basin or guide us to look similar plays in new areas.
Looking Toward the Future
Super Basins are not an accident. Their endowment of hydrocarbons is the result of many different factors that have developed in the optimal time frame with the optimal petroleum system. Understanding what makes these basins work, why they contain the large volume of recoverable reserves and what are the similarities and differences between super basins will be keys to unlocking the ultimate potential of these areas. The most important factor is the presence of a prolific source rock(s). Without an active petroleum system, there are no exploitable hydrocarbons. Sound fundamental analysis and technical innovation will be essential in future exploration programs in these basins, however; as Wallace Pratt said, “Oil is first found, in the final analysis, in the minds of men.”
For information about the upcomingSuper Basins Conference go to http://superbasins.aapg.org/2018