Super-giant oil fields, by definition, are those fields containing at least 5 billion barrels of known recoverable crude oil or gas. It is believed they account for up to 40 percent of the world’s petroleum reserves, so their collective health – how much energy is being created at present, as well as how much can be – will play an oversized role in meeting the world’s future energy needs.
“The interest in future oil supply waxes and wanes depending on price and supply, and these days climate takes up all the discussion about energy supply,” said Richard S. Bishop, past AAPG president and currently an international oil and gas consultant based in Houston.
Complicating the assessment, he said, is that he has not seen an in-depth, unbiased forecast of how fast renewables can be added, which is why the world’s super-giant fields will and must be a vital part of the energy conversation for decades to come.
Bishop references the work of Daniel Yergin, Pulitzer Prize-winning author, specifically Yergin’s latest book, “The New Map: Energy, Climate, and the Clash of Nations,” who contends that the world will be extracting large quantities of fossil fuel for decades – and will still be going to war over them.
As to the march to renewable energy, whatever the rhetoric and goal, Yergin writes in the book, and Bishop wants understood, “The overall objective – net-zero carbon by 2050 – is a daunting ambition. How daunting is underscored by the estimate that, for Europe to achieve its target, per capita emissions will have to decline to the level of India, where per capita income is $2,000 a year, compared to Europe’s $38,000.”
Bishop added that, “while there are lots of numbers in the news about renewable supply adds, they are not based on quantitative and cost-based evaluations. In short, they are far less certain than the oil supply forecasts.”
Peak Oil and Production Plateaus
The question of what kind of role the super giants will play has been an issue with which Bishop has been concerned for more than two decades. Back in 2009, he co-authored a piece with Wayne Kelley and Ron Harrell in the Houston Chronicle entitled, “Global oil supply: Separating fact from fiction,” in which he took to task those who believed there was no danger of running out of oil because of all the untapped oil yet to be realized. In debunking that contention – and it was prevalent back then – Bishop referenced the oft-changing fortunes of the super-giant field, generally, but to make the point clear, compared the landscape and the fortunes to what can be found in one of the pouches of a waitress’s apron.
“Compare an oil field to a glass of water with a straw (our capital cost) as the means of extraction,” he wrote. “A single glass of water can be drained by one straw at a very low cost. To drain the glass faster, add multiple straws for a higher extraction rate and higher cost. Consider that same volume of water poured onto a table. There are now many much smaller puddles that require their own straws. Not only is the unit cost of extracting each small puddle much higher than in the case of the glass, the productivity of each straw is much lower. In practice, it is not possible to produce from the multiple puddles at the same rate as from the glass. We have ‘drunk’ most of the oil from the giant and super-giant fields. What we have left are a few glasses and many, many puddles. Even though there may be many puddles yet to be discovered, it does not change the fact that they produce at a lower rate and at a higher cost than their larger brethren.”
When that piece, more than two decades old, was brought to his attention, he was both amused and heartened.
“I had forgotten about that piece,” he said, “but having just re-read it, I still agree with it.”
He said that is because, even 20 years later, we still know relatively little about many of the super-giants, especially their production histories, their quality of reservoir maintenance and development, their state of depletion, so making production forecasts is a very uncertain exercise.
“Many of the fields, especially in the Middle East, have been on plateau production. These are fields with high-quality reservoirs and in many cases the decline rate is extremely high when the plateau production ends,” he said.
That plateau phenomenon, not limited to the Middle East, was on full display in a report recently issued by WRS, a global workforce solutions provider to the energy, maritime, construction, mining, power, technology and commodities industries, which examined in-depth the health of the top ten super-giant fields.
To summarize the report, five of the top fields, Aghajari (Iran); Bolivar Coastal (Venezuela); Cantarell (Mexico); Daqing (China); and the world’s largest, Ghawar (Saudi Arabia) have shown a reduction in barrels produced, while the others in the Top Ten: Safaniya (Saudi Arabia), Upper Zakum, (UAE), Gachsaran (Iran), Ahvaz Field, (Iran) and Burgan (Kuwait), are either stagnant or stifled by political strife, environmental uncertainties or necessary upgrades and modernization.
Bishop believes that, while the dynamics of how people think about the giant fields has changed, no conclusion can be reached until the limits on renewables and other plays become clearer.
Eclipsed by Unconventionals
Bishop recently addressed these issues in September in Denver at the AAPG-Society of Exploration Geophysicists’ 2021 International Meeting for Applied Geoscience and Energy in a seminar entitled “Origins and Habitats of Super-Giant Fields.” The seminar was part of the Discovery Thinking Forum.
“If anything, the shale revolution has diminished industry interest in super-giant conventionals,” he said.
That, he believes, was short-sighted.
“However, the shale producers are running low on new places to drill in the United States, so we’ll have to wait and see how this very complicated picture evolves.”
In terms of the future of super-giants and what may or may not be their potential, he is not particularly sanguine.
“Has industry’s approach changed?” Bishop asked rhetorically. “Not much. We are probably still as ignorant today as we were yesterday.”