The Gulf of Mexico was essentially written off for a while in 2010 following the infamous Macondo well blowout – but, activity has been revving up, albeit with renewed regulatory oversight.
Despite the Gulf’s long production history, much remains to be learned about the geology here – and an ongoing industry-funded program conducted by the Institute for Geophysics at the Jackson School of Geosciences, University of Texas at Austin (UTIG), is proving to be a rich information resource for GOM players who want to add to their already extensive knowledge of the area.
The 17-year – and counting – Gulf Basin Depositional Synthesis (GBDS) project is based on the premise that the GOM basin is a natural laboratory of sedimentary processes.
Its objective is to assemble and synthesize well, seismic and other data to establish basin-scale depositional history of the Gulf of Mexico, according to AAPG member John Snedden, the program’s newly named director and principal investigator.
This position previously was held by AAPG member Bill Galloway, who led the program along with project coordinator and AAPG member Patty Ganey-Curry, from its initiation in 1995 until last February, when he stepped aside to become part-time consultant for the effort.
The project’s specific goals are:
- Develop and refine offshore to deep basin stratigraphic correlations.
- Create a GIS data base and construct paleogeographic maps.
- Help guide prediction of reservoir distribution and characteristics.
- Address important scientific questions regarding the GOM depositional evolution.
“The Gulf basin is a world-class petroleum system, with more than 900,000 wells drilled on- and offshore,” Snedden said. “The oil industry currently is gathering very expensive well and reflection seismic data in the deepest GOM.
“The basin is a deep hole since the Triassic, with up to 45 percent of the continent’s rivers and deltas attempting to fill it,” he asserted.
“It’s a superb geologic record, he added. “The deep crustal structure is just now being illuminated by UTIG and other refraction seismic studies.”
Putting It In Context
Thus far, the UTIG GBDS team, which includes university students, has focused on the Cenozoic-age sediments, which have sourced many successful discoveries in the region.
“We rely largely on released well data and publications about the Gulf – and it’s a huge volume of data – which we sort and synthesize,” Ganey-Curry said.
“One thing that draws the companies to fund our project is our ability to organize the tremendous amount of data from the GOM,” she said.
Snedden added that another big attraction is the 20 very elaborate paleogeographic maps created by Galloway, which tell a story that helps guide reservoir prediction first and foremost.
Currently, 24 industry sponsors are supporting the program monetarily, with others generously contributing seismic and paleo data. Many of the sponsoring companies are international.
Some of these data can morph into something rather unexpected.
For example, ION Geophysical has put together a unique seismic line from the Florida platform across the entire GOM to offshore Mexico.
“Part of that line is a seismic line shot by UTIG in 1978 before the Law of the Sea Treaty, where you can’t acquire Mexico data anymore,” Ganey-Curry said. “It’s a really valuable offshore seismic line, because today you can’t do that.
“Fortunately, the university kept the old data, and ION went back to the original gathers for that seismic line, reprocessed it and spliced that into the big long regional line that helps paint the entire picture,” she noted.
“It’s the missing part of the puzzle, if you will,” Snedden emphasized.
He commented the GBDS program has been very successful, yielding new insights into the history of the GOM. It provides a context for many recent oil and gas discoveries there, including the Miocene play in Mississippi Canyon and the Paleogene deepwater play in Keathley Canyon and adjacent areas.
Continual Knowledge Transfer
The UTIG team is not inclined to rest on its laurels.
Members are now in the information gathering stage for what is dubbed Phase IX of this endeavor, which will focus on the Mesozoic sediments.
Snedden said the incentive to start working the Mesozoic can be attributed to two relatively recent deep GOM discoveries in the Mesozoic:
- BP PLC’s Tiber well at Keathley Canyon was drilled successfully to the Cretaceous two years ago, by the now-infamous Deepwater Horizon no less, and the well info was only recently released to the BOEMRE. The well tapped into oil in the Paleocene and the Cretaceous.
- The Davy Jones #1 well, drilled by McMoran Exploration on the deep shelf offshore Louisiana, logged 200 feet of net pay in multiple Wilcox sands.
“The Tiber went through 15,000 feet of salt before encountering Wilcox and Cretaceous, so it was a very risky well,” Snedden said. “It reached TD at 35,000 feet in very deep water.
“The salt hides many secrets,” he added.
“It seems that every year there’s a new discovery and a new play and something unusual that the companies want to find out more about, and the GBDS program helps to support that,” he noted.
“We’re always thinking how we can use our information going forward and always adding more data,” Ganey-Curry said. “We’ve built a big interactive GIS database with our own tools for doing things like cross sections and building maps.
“We deliver a lot to the companies for their participation,” she said. “There are always questions to be answered, and there is continual knowledge transfer.”