The past five years have demonstrated that there is still plenty of life left on the Gulf of Mexico shelf, with bypassed oil-rich assets in plentiful supply. Exploration and production operators are now focused squarely on the shelf during this time period, and enjoyed a success rate that has advanced in lockstep with the latest algorithm advancements and vastly improved processing speeds.
Such advances include new inversion methods and bandwidth extensions to improve time to depth and gain a greater understanding of the depositional environment of the shallow sections of the reservoir. New high-frequency algorithms have allowed operators to see thinner sands than they were able to previously, and perform reconnaissance work within the interior pieces of their fields, using the existing logs as a starting point.
As processing speeds have increased exponentially over the past decade, the ability to run more complex algorithms has quickly changed the way infield development is occurring. Additionally, increased processing speed is driving the unit cost of seismic processing down significantly. This is allowing operators to reprocess seismic data on a scale and at a cost that was unthinkable a short time ago. Placing core assets in a regional Seismic advances spur shallow water success context with state-of-the-art reprocessing is unlocking new drilling opportunities.
The datasets reprocessed with these new technologies have allowed some E&P companies, like EPL Oil & Gas, a shallow water operator in the Gulf of Mexico, to average an 80-90% commercial success rate, with this percentage of wells delivering the desired production goals to meet economic objectives. This rate was unheard of two decades ago in the Gulf, with many operators achieving success only 65-75% of the time. The higher rates are indicative of the ability to take much of the mechanical guesswork out of the equation and drill wells in the right spot, by listening closely to what the reprocessed seismic says about reservoirs.
Now, shelf operators are poised to embark on their next phase of shelf exploration, by embracing new, highly sophisticated 3D seismic acquisition and reprocessing whose time has come. Using these advances, the industry will develop a clearer view and understanding of the size and location of previously unexplored hydrocarbon-bearing sands, much deeper into the formation. New reprocessing techniques—many of which have only been commercially available within the last five years—are particularly critical in improving the clarity and resolution of existing data sets that were acquired many years ago.
Technical expertise is just as important as the technology itself. For example, EPL employs experienced geologists and geophysicists who know how to correlate their knowledge of the subsurface rock morphology and marry that with the newly reprocessed data to drill down on a more precise location to land the well. This has reduced the risk profile significantly, and allowed EPL to consistently achieve double-digit rates of return over the past four years.
Further, the algorithm advancements operators are capitalizing on come from a collaborative approach between technical people in the field and the reprocessing software providers. This close and continuing work relationship is critical to tie the seismic to the geology, and ensure that the data set leads to a successful well.
Because this success is a constantly moving target, collaborations such as this will continue, with the aim of consistently improving data resolution with each new algorithm iteration.
Within the next two to five years, it is predicted that much of the GOM shelf will be reshot using new 3D technology, and new algorithms will bring an explosion of new ideas and further derisking. Shallow water operators are not content with waiting for these advancements, but intend to keep working with the seismic community to develop newer processing techniques to improve their understanding of the subsurface, both close to the surface and in deeper recesses of the reservoir.
Andre Broussard is Senior Vice President, Geosciences, at Houston-based EPL Oil & Gas. He has over 28 years of experience in domestic exploration and development as a geologist and geophysicist, focused on the Gulf of Mexico shelf. He began his career in 1984 at CNG Producing Co. Broussard earned a BS in Geology from the University of Southwestern Louisiana.