Bakken Explorers 2015: Exploring with completion techniques

Whiting tests coiled tubing, plug-and-perf, slickwater and cemented liners to find the right geology match and maximize production

Maxine Herr

Petroleum News Bakken

2014 brought a new leader to the number one spot on the production chart in the Bakken/Three Forks system of the Williston Basin when Whiting Petroleum, doing business as Whiting Oil and Gas Corp. in North Dakota, acquired Kodiak Oil and Gas, sealing the deal in December. In September, Whiting ranked third among the top 50 Bakken oil producers in North Dakota according to Department of Mineral Resources data with approximately 78,000 barrels of oil produced per day. After acquiring Kodiak, however, Whiting shot to the top and has remained in that position with more than 128,000 barrels of daily output.

As the basin’s largest producer holding 855,000 net acres and approximately 3,500 net drilling locations, Whiting is also a leader in innovation when it comes to better completion methods and reduced costs. In a March conference call with analysts, Chairman, President and CEO Jim Volker said that Whiting foresees a drop in well costs to $6.5 million in 2015 - a cost the company hasn’t seen since it entered the Bakken in 2007.

The company has its own in-house core lab which allows it to achieve a greater understanding of the geology of the Bakken and Three Forks formations and create state-of-the-art completion techniques to maximize production. Whiting experimented in April 2014 with completions when it drilled three Bakken wells to compare three different designs: older sliding sleeve technology, cemented liners and a coiled tubing fracturing stimulation. Using coiled tubing proved the most successful with production 73 percent higher than sliding sleeves and 40 percent higher than cement liner wells.

“This new completion design better isolates the perforations to more effectively fracture the reservoir,” Volker said at the time, adding that costs are comparable “because there are no plugs to drill out.”

He also said he anticipated coiled tubing to be widely applicable because it allows more entry points within the tight rock.

“I think the main thing here is we’ve been on the hunt to find technologies that can get us more entry points - more reliable entry points,” he said.

Dollars initiate a shift

But by the time Whiting announced its second quarter results in July, it was almost exclusively using plug-and-perf stimulations within its cemented liners. Whiting’s Investor Relations Analyst Brandon Day told Petroleum News Bakken that the main driver is cost which is higher for coiled tubing since it is not as readily available as plug-and-perf equipment.

“(Plug-and-perf) is quick; everyone has that type of equipment. The coiled tubing unit that has to be used on a cemented liner process is pretty unique and hasn’t really moved into the Bakken,” Day said. “So it’s much more expensive than plug-and-perf.”

He said the company doesn’t realize enough of a hike in estimated oil recovery to justify the higher price tag in some areas of the basin.

“If you do a plug-and-perf system with cemented liners and get 20 percent more EORs and the coiled tubing only gets us 21 percent but costs us 20 percent more, profitably it’s just wrong,” he said. “That’s why it’s been phased out in certain areas.”

Coiled tubing is also not yet useable with slickwater fracks, Day said, so in areas where slickwater is the preferred technique, coiled tubing would not be an option. But Whiting is reaping the rewards of applying the best completion process based on formation geology. In 2014, the company’s initial production rates increased by approximately 30 percent year-over-year, as did its 30-, 60- and 90-day average rates. It uses cemented liners and slickwater fracks to target the Bakken, but during a call to discuss fourth quarter 2014 results, Whiting said it was excited about its Three Forks program going into 2015. It said it had “fine-tuned” its completions within the Sanish and Parshall fields by doing a “Three Forks-style” frack. Day said Whiting is using the cemented liners and plug-and-perf process to target the Three Forks, but Senior Vice President of Exploration and Development Mark Williams wasn’t providing much additional detail.

“It’s a little tighter in the Three Forks, and we’ve remapped the Three Forks there and we’re just seeing a whole new renewed interest in our acreage there in Sanish and Parshall,” Williams said. “I think some of the other operators’ off-settings have seen similar things.”

Three Forks productive in Tarpon

The coiled tubing was an effective tool on Whiting’s Flatland Federal well in Tarpon field in northern McKenzie County, which targets the second bench of the Three Forks, allowing the well to flow nearly 6,000 barrels of oil equivalent per day. A few months earlier during the second quarter 2014, Whiting completed a Skaar Federal well within the second bench of the Three Forks in its Tarpon area. It produced more than 6,000 boepd and was completed in 30 stages. An offsetting well produced more than 6,600 boepd from the upper Three Forks. These two initial production rates marked the highest ever for the first and second benches of the Three Forks, based on data from DMR. Whiting actively targets the upper bench of the Three Forks, but it also is testing the third bench in its Tarpon area.

“We think that the third bench has the potential to work through our Tarpon area and beyond, but we’ll take it incrementally as we step out from Tarpon,” Williams told analysts in July.

Tapping the Pronghorn

In the Pronghorn area of Stark and Billings counties, Whiting continues to develop its nearly 127,000 acres. In recent weeks, Whiting wells in this sand formation have made the list of top 10 initial production rates with more than 2,000 barrels per day. Williams said the Pronghorn has performed well with slickwater fracks and the company has begun a new program this year to save money in the low oil price environment. It is fracking its Pronghorn wells with a mix of produced water and freshwater which has proved successful, according to Senior Vice President of Operations Rick Ross.

---

Did you find this article interesting?

Tweet it

Digg it

Print this story | Email it to an associate.

Click here to subscribe to Petroleum News for as low as $89 per year.