Exploration in frontier areas a new reality
Conjugate Margins Ideas Shared
Conjugate margins returned to the global spotlight as geoscientists from around the world gathered in Canada for the second installment of the Central Atlantic Conjugate Margins Conference.
The meeting’s urgency was obvious to the 215 delegates from 17 countries who came to Halifax, Nova Scotia, to revisit the exploration potential of these conjugate margins – especially those of North America – with a renewed interest.
Outstanding outcrop of the barchan-type dune complex at the base of the latest Triassic Blomidon formation, Red Head, Nova Scotia. The paleowind direction is from the right blowing to the southwest and is consistent with northeast trade winds at a position near the Late Triassic Tropic of Cancer.
Photos courtesy of David E. Brown
The expiration of the drilling moratoria on the U.S. Atlantic Outer Continental Shelf this past October, plus the expiration of the drilling moratorium on Canada’s Georges Bank on Dec. 31, 2012, makes exploration in these frontier areas a new reality.
“(In) the entire Central Atlantic alone there are less than 290 wells, excluding the scientific wells,” said conference co-chair David Brown, an AAPG member and a senior petroleum geologist with the Canada-Nova Scotia Offshore Petroleum Board.
“And, there’s been spotty results over almost 50 years of infrequent exploration,” he continued. “The Central Atlantic is, indeed, where Pangea broke apart and where the Atlantic Ocean was born.
“The rocks are older and harder, and they don’t give up their secrets easily.”
Brown said the organizers “were pleasantly surprised by the strong industry participation, sponsorship and papers.
“Obviously, we hit a nerve here,” he added. “The conjugate margins of the Central Atlantic are proximal to huge consumers of energy, both in Europe and North America and, potentially, to the people of northwest Africa.”
Joined at the Hip
This spectacular view is of the famous Triassic-Jurassic boundary at Five Islands, Nova Scotia, Canada. Jurassic CAMP basalts of the North Mountain formation conformably overlay Triassic Blomidon formation playa-lacustrine mudstones with the Triassic-Jurassic boundary located within the light grey sediments under the basalt. This site was a highlight of the Halifax 2008 conference field trip lead by Paul Olsen and Mohammed Et Touhami Olsen this past August.
The inaugural Atlantic conjugate margin conference, organized by the Moroccan Association of Petroleum Geologists, was widely acclaimed. The Halifax session attracted a broad cross-section of speakers, sponsors and representatives from academia, industry, state oil companies and from American and Canadian offshore regulatory agencies.
Titled “Sharing Ideas and Embracing Opportunities,” the conference was sponsored by the Canadian Association of Petroleum Geologists, in association with AAPG, the Atlantic Geoscience Society and sponsors from industry, academia and government.
It investigated two main topics:
- Margin evolution and development.
- Basin petroleum systems.
“We wanted to generate renewed interest in the conjugate margins on both sides of the Atlantic,” said Grant Wach, Brown’s conference co-chair who is a petroleum geoscience professor and director of energy at Dalhousie University, the conference site.
Wach, an AAPG member, described the conference as a “meeting of the minds.”
“We wanted to bring everyone together, from the ‘plate pushers’ to the oil and gas industry field geologists and geophysicists.
Another view is of the famous Triassic-Jurassic boundary at Five Islands, Nova Scotia, Canada. To the left is a complexly-faulted and highly deformed block of Jurassic CAMP basalts of the North Mountain formation. To the right it conformably overlays the Triassic Blomidon formation playa-lacustrine mudstones with the Triassic-Jurassic boundary located within the light grey sediments under the basalt.
“This is the sort of interaction that spurs new play concepts,” he said, “integrating the big scale with the small scale.”
Nova Scotia and Morocco were once joined at the hip in the supercontinent of Pangea, and later separated by the creation of the Atlantic Ocean. The break-up of Pangea led to the development of conjugate margins with analogous petroleum systems on opposite sides of the Central Atlantic.
Today, geologists who study the reservoirs that produce natural gas at Deep Panuke, offshore Nova Scotia, must travel to the High Atlas Mountains of Morocco to view these Jurassic carbonates in outcrop. However, in lieu of traveling to Morocco, conference attendees got to inspect cores from the Late Jurassic Abenaki Formation at EnCana Corporation’s 1.0-Tcf natural gas field at Deep Panuke.
During testing, the H-08 well flowed 50 to 57 mmcf/day of natural gas from Deep Panuke’s hydrothermal dolomite and leached limestone reservoirs.
Diversity – and Atlantic Lobsters
The conference included 45 oral presentations, six keynote speakers, 41 posters and seven core workshop presentations featuring wells from the Scotian Shelf and the Baltimore Canyon Trough on the U.S. continental shelf.
In addition, there were two pre-conference field trips, and pre-conference short courses on salt tectonics and petroleum systems modeling.
According to Wach, participation in the conference was diverse; as a major sponsor, Petrobras, the state oil company of Brazil, hosted a booth and participated geological field trips. Nova Scotia boasts world-class Late Triassic to Early Jurassic outcrops in the Fundy Basin, described as the largest and best-exposed early synrift basin in the Central Atlantic realm.
“Petrobras’ participation in the conference, Wach said, “shows they’re interested in the conjugate margins, and look at the success that they’ve had.
“There were some new ideas to be discussed, and the renewal of old ideas,” Wach added.
Excellent strike view of a 33 metre thick barchan-type dune complex at the base of the latest Triassic Blomidon formation, Red Head, Nova Scotia. This succession overlays Wolfville formation fluvial sandstones and conglomerates and represents the transition from wetter to drier climatic conditions as evidenced by the upper flat-lying playa-lacustrine strata.
And some of the old ideas, he said, still have merit.
“People forget,” he said. “The memory of industry is five years – it’s really short – due to staff changes, mergers and land relinquishments.”
The conference was distinctly ‘Maritime’ in flavor – at the banquet, visitors were given lessons on how to dine on Atlantic lobsters, safely and without inflicting collateral damage. Lunch was served daily in the Dalhousie University Club’s Great Hall, a venue reminiscent of J.K. Rowling’s Hogwarts Hall (with the exception of the food fights).
The conference’s technical sessions were hosted in one venue – there were no concurrent talks or poster sessions – with ample time for questions after each talk.
According to Brown, the participants included 30 students from Canada, the United States, Netherlands, Denmark, Germany, the United Kingdom, France and Morocco.
“We were impressed and delighted that we had a good contingent of students who presented papers, and some of their presentations were mind-blowing,” Brown said. “People get excited about the students, and the enthusiasm from the students is infectious.”