HOUSTON — Key pieces of the subsea equipment used to gather deep-water oil and gas today wouldn’t last long under the pressures and temperatures of ultra-deep reservoirs that oil companies believe are the next frontier.
The lower tertiary of the Gulf of Mexico, where recently discovered ultra-deep reservoirs house billions of barrels of oil and gas, offers some of the highest pressures and temperatures the oil industry has ever encountered. There’s simply no equipment on the market to handle temperatures of 400 degrees Fahrenheit and reservoir pressures of 20,000 PSI, said Patrick Kimball, a spokesman for Houston subsea equipment maker FMC Technologies, during the Offshore Technology Conference in Houston.
Modern subsea trees, manifolds and pipeline pressure-protection systems would all have to be redesigned, but it would take a lot more than just heftier metals for oil companies to be able to exploit the deeper fields.
“It’s not just a matter of building something bigger,” Kimball said. ”There are significant challenges around the seals of the equipment because they operate over a huge temperature range.”
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The water around the wellheads can cool down to 33 degrees Fahrenheit during slow-down periods and heat up to more than 300 degrees when oil and gas is pumping hard through the pipelines. That creates “tremendous technological challenges” around the expansion and contraction of metals and different fatigues.
BP and other Gulf oil producers have staked out ultra-deep spots in the lower tertiary that so far exceed their technological capabilities, he said. As a general rule, the deeper you go offshore, the higher temperatures and higher pressures you’ll find as it’s closer to the center of the earth, Kimball said.
Subsea trees, or sets of valves that allow operators to control the flow of oil and gas flowing out of deep-water wells in the production phase. As pressure regulators, the trees take the job of blow-out preventers once drilling operations are completed, sitting on the top of wells heads.
One subsea tree sitting on the floor at the technology conference in Houston is destined to go to the Gulf of Mexico to plop into Shell’s Stone field about 9,500 feet underwater. FMC Technologies is partnering with BP to develop hardier subsea trees, part of the London oil company’s project to develop equipment to sit on reservoirs of 20,000 PSI.
But making stronger, heavier trees and other subsea equipment means the entire food-chain of products needs to get bigger — from cranes to drill ships, everything needs to bulk up, Kimball said.
“It’s not one thing,” he said. ”It’s a whole system of products that need to be developed. Most of the major operators in the Gulf of Mexico and a lesser extent in other places like offshore Egypt are facing some of these challenges. They’re going to have to develop these technologies.”
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