Refracturing old wells with new technology is likely to become the next hot trend in the Bakken, with one analysis of a field test showing as much as 370,000 barrels of recoverable oil to be had on average from these older wells.
The figure is based on an analysis of 100 or so wells in the Killdeer area by Joel Brown, a principal with Mineral Tracker. Brown has a degree in petroleum engineering from the University of North Dakota, and well performance is one of his specialties.
“That really is a significant amount,” Brown told the Williston Herald. “In most cases it doubled the production those wells were ever going to realize.”
The economics of refracturing such wells are also good, Brown added.
“We don’t have to drill the well again,” he said. “It’s already drilled. It’s showing a great return on investment.”
The number of wells that could benefit by refracturing number in the thousands, Brown added. They include wells done in the early days of the Williston Basin, when companies were just beginning to sort out completion strategies, from 2004 to 2010.
“Almost every one of those wells would be a good candidate for a refracture,” Brown said.
But wells that were completed with newer approaches such as sliding sleeves, popular from 2010 to 2014, are also proving to be good candidates for refracturing.
This was highlighted during the North Dakota Petroleum Council’s recent annual meeting in a presentation by ConocoPhillips Williston Asset Manager Chris Malkin.
Beginning in 2015, most operators moved away from sliding sleeves to plug and perf, including ConocoPhillips, Malkin said.
“As that advance happened, we were left with a significant well population that we wish we had stimulated with the new technology,” he said.
Operators today have better controls for the placement of stimulation downhole Malkin added.
“We think we can have up to 10 more entry points than we did with the previous technology,” he said.
Traditionally, industry had thought refracturing horizontal wells iffy, but field tests by operators are showing otherwise.
“They are finding there is a lot of opportunity to go back into these sliding sleeves,” Brown said. “If that is the case, it opens up an entire new world for completions in the Basin, because a lot of wells were done with that technique.”
Between 2010 and 2014 alone, there were 6,800 wells drilled in the state, Brown said. A majority would have been sliding sleeve completions.
“It’s certainly in the thousands,” he said. “It’s going to add a significant amount of life in the play.”
As far as recent national media reports suggesting shale technology in the Bakken and other plays has hit a ceiling, Brown said it didn’t seem the reports were taking into account how gas flaring regulations are affecting production statistics in North Dakota.
“Because of the flaring regulations that are in place, a lot of operators are choking wells back,” he said. “They don’t have the capacity to take the gas from the location, so if you look at that, what you wind up seeing is you don’t have a natural looking climb on the life of the wells.”
Average first month’s production, a key metric used by many analysts, is thus no longer necessarily representative of new wells completed in the Bakken.
There are, however, glimpses of what the production curves could look. Hess, for example, did a 24-hour test on the recently completed AM-Bombeck well in McKenzie County earlier this year, allowing it to produce without restraint.
“That produced 14,662 barrels of oil equivavalent in the first 24 hours,” Brown said. “It was a record setter for the state and may have been for the Rocky Mountain as well.”
Slawson, too, had a recently completed well that produced 135,000 barrels of oil for the first 30 days, Brown said. That was another record setter.
“It’s hard to get through the obfuscation of what the natural gas regulations on flaring are doing to production,” Brown said. “But in a handful of tests, where operators are opening up the well to see how good it is, we are setting new records it seems consistently in the state.”