As basins such as the Permian have crushed the concept of “peak oil” by doubling past production rates using new ideas and technology, their newly dubbed “super basin” status is inspiring operators on practically every continent to do the same.
A super basin is a basin rich in infrastructure, with one or more prolific petroleum systems, more than 5 BBOE in recoverable reserves and past production of at least 5 BBOE.
Operators and investors from approximately 17 super basins and emerging super basins will discuss their basins’ potential and challenges at the upcoming 2020 Global Super Basins Leadership Conference in Sugar Land, Texas from Feb. 11-13, the third in a series of three hosted by AAPG.
It is the hope of Charles Sternbach, AAPG past president and general chair of the conference, that emerging super basins can seize “lessons learned” from current super basins and “leapfrog ahead” to new discoveries.
“A mood of optimism has replaced a fear of shortage and ‘peak oil’ decline,” Sternbach said. “The industry has returned to the world’s richest petroleum bearing basins with an all-out effort to optimize extensive infrastructure using new technology. This is the advent of super basins and the impetus behind these conferences. Geoscience matters, and it is fitting for AAPG to lead the way.”
Super Basin Strategy
In 2009, global oil consumption was 86 million barrels a day. Today, it is approaching 100 million barrels.
This steady increase is attributed to economic development, but it has been encouraged by relatively inexpensive oil, said AAPG Member Rasoul Sorkhabi, research professor at the University of Utah’s Energy and Geoscience Institute.
During the industry’s recent financial downturn, state oil companies have been relying on reserves and international oil companies have been downsizing exploration programs. However, increased consumption combined with reduced exploration can only be reconciled for so long, Sorkhabi explained.
Despite the fact that the shale revolution – which created super basins from long-produced, conventional fields – is tightly tied to the United States, “There is super basin potential everywhere if you add shale,” Sorkhabi said. “There are 1,050 giant and super giant fields in the world. From those, 470 are located in the Middle East and in the former Soviet Union.”
So, how does one turn a conventional and mature petroleum basin into a super basin?
Petroleum system analysis of shale plays is key.
Hydraulic fracturing has been the common modus operandi behind the shale revolution. “But frac’ing is just a technology,” Sorkhabi said. “You can frac anything. But what are you going to get out of that? You want to make sure that you are frac’ing the sweet spots of the formation.”
When it comes to developing shale plays, one might be tempted to skip petroleum system analysis – believing that past knowledge about their locations is sufficient, Sorkhabi said.
However, many of the mature basins were discovered and developed in the 1910s-‘60s, and source rock studies began in the late ‘70s.
“We know even less about shale as a reservoir,” Sorkhabi said.
When looking at a shale prospect, operators should ask:
- Has it generated oil or gas? Where and when?
- What is the kerogen richness, types and kinetics?
- Is there depositional heterogeneity across the basin?
- Are there lithological variations, such as limy, silty or sandy layers in the formation?
- How can various types of porosity be quantified?
- What are the linked dynamics of oil and gas in the reservoir and during production?
- How do the wells interact?
- What is the local environmental footprint, and how can one operate responsibly?
“We need to go beyond this vague umbrella term of ‘shale’ and really look at our rocks,” Sorkhabi said. “Petroleum systems are very integrated physical, geochemical, sedimentological and structural processes. All unconventional plays are located in conventional basins. They need to be studied using a detailed and holistic approach.”
Australia on the Rise
With a world-class petroleum system, Australia’s Cooper Basin is emerging on the super basin map. It is the country’s largest conventional onshore basin estimated to have generated and expelled up to 1,272 BBOE. It has tremendous potential for becoming a super basin because of its petroleum system, infrastructure, and support for enterprise from the government, Sternbach said.
With at least 10 distinct Permian source rock intervals that are dominated by Permo-Triassic coals, the Cooper is home to at least 166 oil fields and 256 gas fields to date. While gas is the dominant phase in the basin, the overlying Jurassic-Cretaceous aged Eromanga Basin is a predominantly oil province.
“Although the Cooper is a mature exploration province, the ultimate potential of the basin is relatively underexplored,” said AAPG Member Sandy Watters, general manager of Onshore Near Field Exploration at Santos Ltd. “The basin has significant untapped resource potential residing within unconventional plays.”
Santos has identified 29 distinct working play intervals, each containing multiple local reservoir/seal pairs resulting in complexity that provides both opportunity and challenge with conventional plays. Opportunities also exist with large volumes of gas in unconventional traps across the basin, including the Deep Coal play.
Yet for the Cooper to be recognized as a super basin, several challenges must be overcome, including drilling and completion technologies to exploit targets at depths of around 10,000 feet or greater – where high pressures and temperatures are the norm.
“Unconventional resources will require innovative techniques with horizontal drilling and fracture stimulation to unlock their potential,” Watters said.
Furthermore, some of the fluvial reservoirs have been shown to be susceptible to damage, so finding waysto drill without exposing the formation to damaging fluids is needed,” she said.
While 3-D seismic surveys have potential to deliver value, innovative solutions with survey acquisition design and nodal technologies are being tested to improve imaging in the basin.
Despite challenges, the Cooper has become noteworthy worldwide.
“In general, Australia has a very stable fiscal regime which makes exploiting the Cooper Basin politically low risk,” Watters said. “Significant investment in infrastructure within the basin means that new discoveries can be rapidly brought online, and with the growth of the Australian East Coast gas market and access to LNG terminals, the full potential of the basin could be realized economically.”
Watters added, “The success of North American unconventionals and our own Aussie pioneering spirit gives rise to a lot of optimism here in Australia as to what can be achieved in the future.”
Powder River, the Next Permian?
Although the Permian Basin has become the prototype for super basins, the emerging Powder River Basin in Wyoming and Montana might be running a close second, said AAPG Member Steve Sonnenberg, professor and Charles Boettcher chair in geology at the Colorado School of Mines.
In the past, the basin has produced 3.1 BBOE. When that volume is combined with new production volumes and reserves, the Powder River Basin will be categorized as a super basin, Sonnenberg said.
Covering 43,000 square-miles and running up to 17,000 feet in thickness, the Powder River Basin has a world-class petroleum system that has drawn strong operators to the Mowry and Niobrara mud rock formations. In tighter sand plays, such as the Frontier and Turner sandstones, production is estimated to be 530,000 BOE per well in the Frontier and 600,000 BOE per well in the Turner, according to TGS, a subsurface data company based in Houston.
With current oil production in the basin around 125,000 barrels a day (up from 38,000 barrels a day in 2009), the Powder River Basin “is on an upswing as we speak,” said Sonnenberg.
“The basin is very attractive because it has multiple stacked plays,” he said. “It’s on the verge of kicking off in a major way.”
“We jokingly say the Powder River Basin is the next Permian because it has all the right ingredients and all the attraction that a company would want,” Sonnenberg said. “Historically, the Rocky Mountain region and the Powder River Basin has always been the basin that was thought to have the most oil and a significant amount of gas, too.”
Referring to the Williston Basin in the Bakken, which produces 1.4 million barrels of oil a day, Sonnenberg believes the Powder River Basin is not too far behind.
“Do I think the Powder River Basin can get to a million? Yes, I do,” he said. “We are on our way to that. It’s a hockey stick increase of oil production as of late.”
According to Sternbach, “The onshore and offshore global energy renaissance is just getting started.”