Whiting Petroleum’s field strategy in the Williston Basin is to look for two types of development opportunities: one, new zones to exploit in and outside of the Bakken petroleum system, and; two, increasing the density of wells on existing production.
Whiting had record production during the 2013 first quarter, averaging 89,135 barrels of oil equivalent per day company-wide, a 10 percent increase over first quarter 2012 production of 80,747 boe per day, and a 4 percent increase over the fourth quarter 2012 average of 86,055 boe per day.
“And we’re on track to post a year-over-year production gain of between 12 percent and 16 percent,” James Volker, Whiting’s chairman and chief executive officer, said in a first-quarter conference call with industry analysts in late April.
Seventy-four percent of Whiting’s total production comes from the company’s core Rocky Mountain region, with more than 60 percent of the total coming directly from the Bakken and Three Forks plays in the Williston Basin. In April 2013, the most recent month reported by the North Dakota Department of Minerals, Whiting-operated Bakken wells produced an average of 68,815.4 barrels of oil per day, making Whiting the second largest Bakken system oil producer in the state.
Part of the company’s success in the Williston Basin can be attributed to a slew of successful projects, starting with drilling at its Sanish, Pronghorn, Hidden Bench and Tarpon fields that continue to “underpin” its healthy production increases, per Volker.
One of its most interesting recent vertical exploratory efforts is Whiting’s plan to test an untapped and highly prospective oil formation within the Bakken petroleum system known as the lower Bakken silt.
Sandwiched between the non-producing lower Bakken shale and the Pronghorn sand, the lower Bakken silt is right above the Three Forks formation (see Hidden Bench information in adjacent chart titled “Williston Basin Primary and Prospective Drilling Plan by Area”).
Whiting says the silt is situated in the central portion of the Williston Basin, and according to Volker is “primarily present” at the company’s Hidden Bench prospect in North Dakota’s McKenzie County.
Whiting said it identified the zone through extensive core sampling, which “demonstrated high oil in place and may significantly increase reserves in this area.”
The company is so confident about transforming the silt into production that it plans to invest millions of dollars “bracketing” the formation with as many as eight wells above and seven wells below the silt. The wells, to be drilled on 160-acre spacing, might even improve current production from the middle Bakken zone, the company said in discussing first quarter 2013 results.
Previous ‘silt’ drilling failed
Whiting said it previously attempted to drill into the lower Bakken silt but ran into difficulties when the drill bit got stuck in the formation.
“So our approach here is essentially to drill both above it in the middle Bakken and below it in the Three Forks and essentially frack simultaneously to develop this zone,” Mark Williams, Whiting’s senior vice president of exploration and development, told analysts March 4, 2013, at the Raymond James Institutional Investors Conference in Orlando, Fla.
“It represents a tremendous resource for us as we go forward in developing this,” he added, explaining Whiting’s field strategy for the basin.
Most Bakken petroleum system oil in the Williston Basin is currently produced from the middle Bakken tight oil reservoir, consisting of sandstone, siltstone, dolomite and mudstone sandwiched between two zones of shale, the most common source rock for petroleum, as well as the upper bench of Three Forks formation, another non-shale, tight reservoir, made up of silty dolostone, clay-rich dolostones, red beds and anhydrites.
Well-density projects
In 2013 Whiting is conducting pilot well density programs at Pronghorn and Hidden Bench fields, along with its flagship Sanish field in Mountrail County, N.D., in an effort to strengthen production.
Sanish, one of the first middle Bakken discoveries in the basin, alone represents nearly 40 percent of Whiting’s total production; by spacing wells closer together, the company believes it may be able to boost the oil recovery rate 15-17 percent from its current 10-11 percent.
If successful at Sanish, the company said, it could add an additional three middle Bakken locations per 1,280-acre spacing unit. The company also plans to refracture several wells in the field in 2013.
At Pronghorn, Whiting plans to drill six Pronghorn sand wells per 1,280-acre spacing unit, which is up from the company’s initial plan of three wells per spacing unit.
A noted explorer and powerhouse in the Williston Basin, Whiting is generally credited with discovery of the productive Pronghorn sand zone in southern North Dakota at the company’s Pronghorn prospect in Stark County. The zone lies above the Three Forks and below the lower Bakken silt.
“At Hidden Bench … we have the opportunity not only to do higher (well) density, but to develop that lower Bakken Silt zone,” Williams said.
“If successful this would add over 116 net locations at Pronghorn and over an additional 160 net locations at Hidden Bench,” Volker said
Pronghorn’s ‘exceptional’ results
Production from Whiting’s Pronghorn and Lewis & Clark prospects, located in in the southern Williston Basin and encompassing 396,482 gross (262,194 net) acres, averaged 13,800 boe per day in the first quarter, a whopping 52 percent increase over the 9,055 boe per day rate in 2012’s first quarter.
Whiting said it had “exceptional” drilling results in the fourth quarter 2012, including eight wells with 24-hour initial production rates exceeding 2,000 boe per day.
Production from the Western Williston Basin, which includes Hidden Bench, Tarpon, Missouri Breaks and Cassandra, averaged 6,520 boe per day in the first quarter, representing a 27 percent increase over the 5,120 boe per day average rate in the fourth quarter of 2012. The area encompasses a total of 182,913 gross (114,454 net) acres.
Whiting said Tarpon produced the third highest well flow rate (Federal 21-4-3H) in the history of the Williston Basin — 6,879 boe per day (4,971 barrels of oil) during its first 24 hours of production in December 2012 from the middle Bakken interval. The company has also begun pad drilling at Tarpon with immediate plans to drill three wells off each pad.
Of note at Missouri Breaks during the first quarter was the Miller 34-8-1H in the middle Bakken formation flowing at 1,475 boe per day, “our best rate to date in the field,” the company said. Whiting holds 95,803 gross (65,481 net) acres in the prospect, located in Richland County, Mont., and McKenzie County, N.D.
The first well drilled in the eastern portion of Missouri Breaks, the Amber Elizabeth 9-4H in the middle Bakken, flowed 1,315 boe in its first day of production in October.
Sanish output keeps rising
Net production from Whiting’s legacy Sanish field averaged 31,081 boe per day in 2012, a whopping 40 percent increase over 2011 levels, the company reported.
First-quarter 2013 net production from Sanish alone contributed an average 33,300 boe per day, a hefty 16 percent jump from the 28,790 boe per day average recorded in 2012’s first quarter.
Sanish output now represents 37 percent of Whiting’s entire production.
Whiting noted the completion of the Fladeland 14-33H in an April conference call, a well that was completed in the middle Bakken flowing 3,220 boe per day in its first 24 hours of production. The well’s 7,279-foot lateral was fracked in a total of 22 stages.
What about Three Forks lower benches?
Whiting Petroleum doesn’t see eye-to-eye with fellow Bakken producer Continental Resources when it comes to the possible far-reaching significance of Continental’s successful production test from the first-ever horizontal well completed in the third bench of the Three Forks.
Continental believes the Charlotte 3-22H, in North Dakota’s McKenzie County, is an important step in assessing the productivity of the lower Three Forks reservoirs.
Charlotte 3-22H is the first of 14 wells that will test three benches of the Three Forks and could lead to a substantial increase in the amount of oil Continental thinks can be recovered from the giant Bakken petroleum system.
“So they’ve drilled their well and it’s looking pretty positive there,” James T. Brown, Whiting’s president and chief operating office, told analysts at the Dec. 5, 2012, Wells Fargo Securities Energy, MLP and Pipeline conference in New York.
However, because the well is situated in the most oil prolific area of the Williston Basin, coupled with its own drilling experiences, Whiting concludes that Continental’s lofty expectations for the lower Three Forks are probably limited to the middle portion of the basin.
“We have tried it farther out on the edge of the basin,” Brown said. “I can’t say that we were real enthused with it.” He said Whiting even drilled a horizontal well into the first bench of the Three Forks on its southwest Hidden Bench property.
“We did not find the encouragement we needed,” Brown added.
It’s Whiting’s view that the oil originates in the lower Bakken shale and was forced down into the Three Forks. The Charlotte 3-22H happens to be in a deep portion of the basin, where the oil flows hotter and under higher pressure than other areas, and where more oil is generated from the shale than any other portion of the Bakken.
“In Whiting’s opinion, it’s not going to work everywhere, but it definitely could work out in the middle part of the basin,” Brown said.
Nevertheless, “We’re going to be keeping an eye on what they do because it could become something. And we wish them all the luck in the world.”
Tapping the Red River
In its evaluation of another petroleum system in the Williston Basin, Whiting identified more than 50 vertical Red River prospects at its Big Island play, consisting of 172,464 gross (122,389 net) acres in Golden Valley County, N.D., and Wibaux County, Mont.
Additional 3-D seismic is being shot on the northwest portion of Big Island to identify any more prospect locations, the company said, noting that estimated ultimate recoveries for wells range from 200,000 boe to 300,000 boe. And the wells have estimated completion costs per well of just $5-$5.5 million.
But another largely untested lower Red River D zone, which might be suited for horizontal drilling, could be a “major game-changer” for the company.
In the last half of 2013, Whiting plans to drill what it believes will be the first horizontal well to enter the lower Red River D zone. If successful, the addition of horizontal wells, which significantly increase well-bore exposure to oil, could dramatically change the production dynamics of the play, the company indicated.
Whiting characterizes Red River as one of the oldest known but least understood geological trends in the Williston Basin. The company holds large acreage positions in several counties the trend crosses in eastern Montana and western North Dakota.
“We’re nine for 10 on drilling Red River bumps — traditional bumps found with 3-D seismic,” Volker told analysts at an April 15 conference in New York hosted by the Independent Petroleum Association of America, IPAA.
“So there’s the great economics, quick payouts here in around 12 months — and then three-to-one, four-to-one, on your money,” he added.
Bakken-like ‘porosity highlights’
Interesting anomalies have appeared in Whiting’s extensive 3-D seismic studies — Bakken-like horizontal “porosity highlights” in the Lower Red River “D” zone at Big Island.
“It’s very similar to drilling in a lower porosity zone like the Bakken,” Volker explained. “It really would allow us to go horizontal in areas that essentially show up on our 3-D, sort of between the porosity indications that are seen on the 3-D.”
He added: “With these large acreage positions that we hold here, they may turn into a horizontal play as well as a vertical play. If that happens, it’s a major game-changer for Whiting and some of the other producers in the area.”
However, the massive Bakken shale formation itself, a world-class unconventional play being developed with horizontal wells, does not exist in the Big Island prospect, said Williams.
And though the underlying Three Forks formation is present, he added, it’s not a prospective reservoir without the Bakken “to charge it.”
Other operators have successfully drilled into the Red River B zone in the southern Williston Basin.
Starbuck, Missouri Breaks and another Whiting prospect, Lewis & Clark, are prospective in the B and C zones with both vertical and horizontal wells, Williams said, adding the company would be testing them later in 2013.
