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Redoubt production impacted by water
Kay Cashman Petroleum News Publisher & Managing Editor
Oil production from Forest Oil’s Redoubt Shoal field in Alaska’s Cook Inlet is slowly dropping off and will continue to do so until more wells are brought on line and secondary recovery with water flood comes on-line in 2004.
Tanker delays at Drift River where oil is loaded for shipment was one of the first problems faced by Forest at the offshore field, which started up Dec. 9 and is thought to hold more than 100 million barrels of recoverable oil. That challenge has been partly alleviated and company officials think it can be further addressed during contract negotiations, but another factor has cropped up, impacting oil production. Water problem unusual The oil reservoir is producing unexpectedly large amounts of water, Gary Carlson, Forest Oil’s senior vice president for Alaska, told Petroleum News June 6.
He said Redoubt production from four wells in the Hemlock participating area “with certain amounts of down time” has dropped from about 4,000 barrels a day in April to an “average of about 3,500 barrels of oil a day” in early June. It is currently producing “just under 3,000 barrels of water per day.”
Production will “continue to slowly drop off until we can get more wells on. Water flood will also bring that up,” Carlson said.
“We’ve got some inter-bedded water in the Hemlock, which is unusual. Usually you would find a common oil-water interface that would be consistent across the field,” he said.
“Three of the wells produced some water initially. Even the best well, Redoubt No. 2, which produces 1,100 to 1,200 barrels per day, produces 200 gallons of water per day. … You couldn’t tell from the logs. It was unexpected,” Carlson said.
Handled solution efficiently Eventually Forest will be reinjecting the water, but secondary recovery with water flood wasn’t scheduled to start until late 2004, Carlson said, so in the meantime, the company had to find a place to dispose of the water, and quickly.
A state official said Forest responded quickly to the problem of excess water production.
“We got a permit to dispose of the water in a wildcat we’d purposely saved, the Tom Cat,” which was drilled and plugged and abandoned several years ago. “We built our onshore processing facilities right on top of the oil drilling pad to minimize our footprint over there,” Carlson said.
Well drilling is also going more slowly than expected.
It takes about three months to drill a Redoubt well, he said, which is longer than the company originally anticipated and, combined with the other challenges, puts the company behind schedule to have seven oil wells drilled by the end of the year.
A fifth oil well is expected to come online in the next month and a half, Carlson said. Currently, “we’re re-drilling No. 4, putting it in a better location.”
“It’s going slower than we wanted. … It’s been a little frustrating that we haven’t got more wells in,” he said. May sell gas from Redoubt In May, the company completed and put online its first gas well, Redoubt No. 3, which recently tested at 8.6 million cubic feet a day.
“We had some mechanical problems in the Hemlock with No.3. We had a gas discovery there, so we completed it as a gas well,” Carlson said.
“No. 4 well also tested a little bit of gas. We’re re-drilling it now to make it a more efficient oil producer.” Because of what Forest has found so far, Carlson said it is “highly likely (Redoubt has) … more gas potential in the shallower sand, which is where we found gas in No. 3.”
The gas, which has proven another distraction from the company’s main objective — i.e. to produce oil — will be used for fuel for the Redoubt operation, Carlson said.
“If there’s enough gas, we’ll sell some. We’re evaluating what we’re going to do now,” he said, but “we didn’t count on any gas. … We want to drill oil wells.”
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