Bakken formation

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Bakken formation
Stratigraphic range: Late Devonian to Early Mississippian
Type Geological formation
Unit of Three Forks Group
Underlies Madison Limestone
Overlies Wabamun Formation, Big Valley Formation, Torquay Formation
Area 200,000 square miles (520,000 km2)
Thickness up to 40 metres (130 ft)[1]
Lithology
Primary Shale, Dolomite
Other Sandstone, Siltstone
Location
Region Williston Basin of
central North America
Country  United States,  Canada
Type section
Named for Henry Bakken
Named by J.W. Nordquist, 1953
Bakken Reservoir fields in Williston Basin.jpg
Map of Bakken Formation reservoirs in the US portion of the Williston Basin (Saskatchewan is north border). Prior to 2007, most oil came from the Elm Coulee Oil Field.
Schematic north-south cross section showing the Bakken and adjacent formations (USGS, 2013)
Map of Bakken wells in the US as of 2008, largely restricted to the southwest pinchout and the Nesson Anticline (USGS, 2013)
US Bakken and Three Forks wells as of 2013

The Bakken formation /ˈbɑːkən/ is a rock unit from the Late Devonian to Early Mississippian age occupying about 200,000 square miles (520,000 km2) of the subsurface of the Williston Basin, underlying parts of Montana, North Dakota, Saskatchewan and Manitoba. The formation was initially described by geologist J.W. Nordquist in 1953.[2] The formation is entirely in the subsurface, and has no surface outcrop. It is named after Henry Bakken, a farmer in Tioga, North Dakota who owned the land where the formation was initially discovered, during drilling for oil.[3]

Besides being a widespread prolific source rock for oil when thermally mature, there are also significant producible reserves of oil within the Bakken formation itself.[4] Oil was first discovered within the Bakken in 1951, but past efforts to produce it have faced technical difficulties. In April 2008, a USGS report estimated the amount of recoverable oil using technology readily available at the end of 2007 within the Bakken Formation at 3.0 to 4.3 billion barrels (680,000,000 m3), with a mean of 3.65 billion.[5] The state of North Dakota also released a report that month which estimated that there are 2.1 billion barrels (330,000,000 m3) of technically recoverable oil in the Bakken.[6] Various other estimates place the total reserves, recoverable and non-recoverable with today's technology, at up to 24 billion barrels. A recent estimate places the figure at 18 billion barrels.[7] In April 2013, the US Geological Survey released a new figure for expected ultimate recovery of 7.4 billion barrels of oil.[8]

The application of hydraulic fracturing and horizontal drilling technologies have caused a boom in Bakken production since 2000. By the end of 2010 oil production rates had reached 458,000 barrels (72,800 m3) per day outstripping the pipeline capacity to ship oil out of the Bakken.[9][10] The production technology gain has led a veteran industry insider to declare that the USGS estimates are too low.[11]

Geology[edit]

Lower Bakken-3 Forks Transition

The rock formation consists of three members: lower shale, middle dolomite, and upper shale. The shales were deposited in relatively deep anoxic marine conditions, and the dolomite was deposited as a coastal carbonate bank during a time of shallower, well-oxygenated water. The middle dolomite member is the principal oil reservoir, roughly two miles (3.2 km) below the surface. Both the upper and lower shale members are organic-rich marine shale.

Oil and gas[edit]

The Bakken has emerged in recent years as one of the most important sources of oil in the United States. Most new Bakken drilling and production has been in North Dakota, although the play also extends into Montana, Saskatchewan, and Manitoba. As of 2013, the Bakken produced more than ten percent of all US oil production. In November 2013, the US Energy Information Administration projected that Bakken production in North Dakota and Montana would exceed one million barrels per day in December 2013.[12] As a result of the Bakken, North Dakota as of 2013 is the second largest oil-producing state in the US, behind only Texas in volume of oil produced.[13]

Bakken production has also increased in Canada, although to a lesser degree than in the US, since the 2004 discovery of the Viewfield Oil Field in Saskatchewan. The same techniques of horizontal drilling and multi-stage massive hydraulic fracturing are used. In December 2012, 2,357 Bakken wells in Saskatchewan produced a record high of 71,000 barrels of oil per day.[14] The Bakken Formation also produces in Manitoba, but the yield is small, averaging less than 2,000 barrels per day in 2012.[15]

Drilling and completion[edit]

Most Bakken wells are drilled and completed in the middle member. Many wells are now being drilled and completed in the basal Sanish/Pronghorn member and in the underlying Three Forks Formation, which the North Dakota Department of Mineral Resources treats as part of the Bakken for oil production statistical purposes.

Porosities in the Bakken averages about 5%, and permeabilities are very low, averaging 0.04 millidarcies—much lower than typical oil reservoirs, in today's terms a light tight oil play.[16] However, the presence of vertical to sub-vertical natural fractures makes the Bakken an excellent candidate for horizontal drilling techniques in which a well drills horizontally along bedding planes, rather than vertically through them. In this way, a borehole can contact many thousands of feet of oil reservoir rock in a unit with a maximum thickness of only about 140 feet (40 m).[17]

Production is also enhanced by artificially fracturing the rock,[18] to allow oil to seep to the oil well.

Bakken oil is "sweet," meaning that it has little or no hydrogen sulfide. The academic community commented in 2011 that increased concentration of H2S had been observed in the Bakken field and presented challenges such as "health and environmental risks, corrosion of wellbore, added expense with regard to materials handling and pipeline equipment, and additional refinement requirements".[19]

History of Bakken oil resource estimates[edit]

Oil in place[edit]

A research paper by USGS geochemist Leigh Price in 1999 estimated the total amount of oil contained in the Bakken shale ranged from 271 billion to 503 billion barrels (8.00×1010 m3), with a mean of 413 billion barrels (6.57×1010 m3).[20] While others before him had begun to realize that the oil generated by the Bakken shales had remained within the Bakken, it was Price, who had spent much of his career studying the Bakken, who particularly stressed this point. If he was right, the large amounts of oil remaining in this formation would make it a prime oil exploration target. However, Price died in 2000 before his research could be peer-reviewed and published. Nevertheless, the drilling and production successes in much of the Bakken beginning with the Elm Coulee Oil Field discovery in 2000 have proven correct his claim that the oil generated by the Bakken shale was still there.[21] In April 2008, a report issued by the state of North Dakota Department of Mineral Resources estimated that the North Dakota portion of the Bakken contained 167 billion barrels (2.66×1010 m3) of oil in place.[6]

Recoverable oil[edit]

Although the amount of oil in place is a very large oil resource, the percentage that can be extracted with current technology is another matter. Estimates of the Bakken's recovery factor have ranged from as low as 1% — because the Bakken shale has generally low porosity and low permeability, making the oil difficult to extract — to Leigh Price's estimate of 50% recoverable.[22] Reports issued by both the USGS and the state of North Dakota in April 2013 estimates up to 7.4 billion barrels of oil can be recovered from the Bakken and Three Forks formations in the Dakotas and Montana, using current technology.[23] The flurry of drilling activity in the Bakken, coupled with the wide range of estimates of in-place and recoverable oil, led North Dakota senator Byron Dorgan to ask the USGS to conduct a study of the Bakken's potentially recoverable oil. In April 2008 the USGS released this report, which estimated the amount of technically recoverable, undiscovered oil in the Bakken formation at 3.0 to 4.3 billion barrels (680,000,000 m3), with a mean of 3.65 billion.[5] Later that month, the state of North Dakota's report [6] estimated that of the 167 billion barrels (2.66×1010 m3) of oil in-place in the North Dakota portion of the Bakken, 2.1 billion barrels (330,000,000 m3) were technically recoverable with current technology.

In 2011, a senior manager at Continental Resources Inc. (CLR) declared that the "Bakken play in the Williston basin could become the world’s largest discovery in the last 30-40 years", as ultimate recovery from the overall play is now estimated at 24 billion bbls.[24] (Note: the recent discoveries off the coast of Brazil should be greater, with proven reserves of 30 billion,[25] and a potential for 50 to 80.[26]) This considerable increase has been made possible by the combined use of horizontal drilling, hydraulic fracturing, and a large number of wells drilled. While these technologies have been consistently in use since the 1980s, the Bakken trend is the place where they are being most heavily used: 150 active rigs in the play and a rate of 1,800 added wells per year.[citation needed]

An April 2013 estimate by the USGS projects that 7.4 billion barrels of undiscovered oil can be recovered from the Bakken and Three Forks formations and 6.7 trillion cubic feet of natural gas and 530 million barrels of natural gas liquids using current technology.[23][27][28]

The US Energy Information Administration estimated in 2013 that there were 1.6 billion barrels and 2.2 trillion cubic feet (tcf) of technically recoverable oil and natural gas in the Canadian portion of the Bakken formation.[29] Crescent Point Energy and other operators are implementing waterfloods in the Bakken Formation of the Viewfield Oil Field in Saskatchewan. Some believe that waterflooding can raise the recovery factor at Viewfield from 19 percent to more than 30 percent, adding 1.5 to two billion barrels of additional oil.[30]

Proved reserves[edit]

The US EIA reported that proved reserves in the Bakken/Three Forks were 2.00 billion barrels of oil as of 2011.[31]

History of Bakken Oil[edit]

Monthly oil production from the Bakken and Three Forks formations in North Dakota
Oil wells producing from the Bakken Formation, US and Canada in 2011
Natural gas production from the Bakken/Three Forks (US only)
Pulling the Bakken Core out of the core barrell
Bakken Core

The Bakken formation has produced oil since 1953, when a North Dakota well was completed in the Bakken.

The 2000 discovery of the Elm Coulee Oil Field, Richland County, Montana, where production is expected to ultimately total 270 million barrels (43,000,000 m3) drew a great deal of attention to the trend where oil was trapped along the Bakken pinchout. In 2007, production from Elm Coulee averaged 53,000 barrels per day (8,400 m3/d) — more than the entire state of Montana a few years earlier.[32] The Mondak Field to the southeast of Elm Coulee extended the productive pinchout trend into North Dakota. Elm Coulee was key to later Bakken development because it combined horizontal wells and hydraulic fracturing, and targeted the dolomitic middle Bakken member rather than the shales of the upper or lower Bakken.

New interest developed in 2006 when EOG Resources reported that a single well it had drilled into an oil-rich layer of shale near Parshall, North Dakota was anticipated to produce 700,000 barrels (110,000 m3) of oil.[33] At Parshall, the abrupt eastern limit of the field is formed by the extent of thermally mature Bakken shale; shale farther east is thermally immature.[34]

The Parshall Oil Field discovery, combined with other factors, including an oil-drilling tax break enacted by the state of North Dakota in 2007,[35] shifted attention in the Bakken from Montana to the North Dakota side.[36] The number of wells drilled in the North Dakota Bakken jumped from 300 in 2006[37] to 457 in 2007.[38]

The viability of the play in North Dakota west of the Nesson Anticline was uncertain until 2009, when Brigham Oil & Gas achieved success with larger hydraulic fracturing treatments, with 25 or more stages.[39]

According to North Dakota government statistics, daily oil production per well seems to have peaked (or at least reached a plateau) at 145 barrels in June 2010.[40] Although the number of wells doubled between June 2010 and December 2011, oil production per well remains essentially unchanged. However, total oil produced continues to increase, as more wells are brought online.

Exploration and production[edit]

North Dakota oil production

A number of publicly traded oil and gas companies have drilling rigs in the Bakken trend. These include EOG Resources Inc.,[41] Continental Resources Inc.,[42] Whiting Oil & Gas Inc.,[43] Marathon Oil Corporation,[44] QEP Resources,[45] Hess Corporation,[46] Samson Oil and Gas Ltd,[47] In Canada, operators include Lightstream Resources (formerly PetroBakken Energy),[48] Crescent Point Energy, and Tundra Oil & Gas Partnership.[49]

There are several companies whose Bakken holdings and tight oil expertise may have made them attractive takeover targets. XTO Energy was bought by ExxonMobil in 2010. The Norwegian company Statoil bought Brigham Exploration in 2011.[50][51]

Oil and gas infrastructure[edit]

The great increases in oil and gas production have exceeded the areas's pipeline capacity to transport hydrocarbons to markets. There is only one refinery in the area. The result has been that the oil and gas prices received have been much lower than the normal North American index prices of West Texas Intermediate for oil and Henry Hub for gas.[52]

The shortage of pipeline capacity has caused some producers to ship oil out of the area by more expensive methods of truck or railroad. It was Bakken crude oil carried by train that caught fire in the deadly 2013 Lac-Megantic derailment in Quebec.[53]

In March 2013, Canadian pipeline company Enbridge completed a pipeline to take North Dakota oil north into Canada, where it hooks up to Enbridge's main pipeline delivering western Canadian oil to refineries in the American Midwest. Unlike the stalled cross-border Keystone XL Pipeline, the pipeline project to carry American crude across the border was approved by the US government without controversy.[54]

Absent the infrastructure to produce and export natural gas, it is merely burned on the spot; a 2013 study estimated the cost at $100 million per month.[55]

Effects of the boom[edit]

Main article: North Dakota oil boom

The oil boom has given those who own mineral rights large incomes from lease bonuses and royalties. The boom has reduced unemployment and given the state of North Dakota a billion-dollar budget surplus. North Dakota, which ranked 38th in per capita gross domestic product (GDP) in 2001, rose steadily with the Bakken boom, and now has per capita GDP 29% above the national average.[56]

The industrialization and population boom has put a strain on water supplies, sewage systems, and government services of the small towns and ranches in the area.[57][58][59] Increasing economic prosperity has also brought increasing crime and social problems.[60]

See also[edit]

References[edit]

  1. ^ Lexicon of Canadian Geological Units. "Bakken Formation". Retrieved 2009-03-26. 
  2. ^ Nordquist, J.W., Mississippian stratigraphy of northern Montana, Billings Geological Society, 4th Annual Field Conference Guidebook, pp. 68–82, 1953
  3. ^ Bakken Formation: Will it fuel Canada's oil industry?, June 27, 2008, cbc.ca.
  4. ^ US Energy Information Administration, November 2008, Technology-based oil and natural gas plays: Shale shock! Could there be billions in the Bakken?, PDF file, retrieved 16 January 2009.
  5. ^ a b "3 to 4.3 Billion Barrels of Technically Recoverable Oil Assessed in North Dakota and Montana’s Bakken Formation—25 Times More Than 1995 Estimate". U.S. Geological Survey. April 10, 2008. Archived from the original on 11 April 2008. Retrieved 2008-04-11. 
  6. ^ a b c ND study: 167 billion barrels of oil in Bakken
  7. ^ http://www.nd.gov/ndic/ic-press/bakken-form-06.pdf
  8. ^ US Department of the Interior, USGS releases new oil and gas assessment for Bakken and Three Forks, 30 Apr. 2013.
  9. ^ "New Drilling Method Opens Vast U.S. Oil Fields". FoxNews.com. 2010-04-07. Retrieved 2011-02-23. 
  10. ^ "Producers turn to railroads for shipping Bakken crude". Tulsa World. 2011-01-28. Retrieved 2011-02-23. 
  11. ^ "The Virginia Gazette, Williamsburg Virginia > News > Update on oil". Vagazette.com. Retrieved 2011-02-23. 
  12. ^ US EIA, Bakken oil production forecast to top 1 million barrels per day next month, Energy Today, 15 Nov. 2013.
  13. ^ US EIA, Crude oil production, accessed 17 Sept. 2013.
  14. ^ Dan Kohlruss and others, Well stimulation observations in the Viewfield Bakken pool, 2013.
  15. ^ Government of Manitoba, Manitoba oil facts, accessed 17 Sept. 2013.
  16. ^ Diagenesis and Fracture Development in the Bakken formation, Williston Basin: Implications for Reservoir Quality in the Middle Member, by Janet K. Pitman, Leigh C. Price, and Julie A. LeFever, U.S. Geological Survey Professional Paper 1653, 2001.
  17. ^ Donald Barrs, Devonian System, in Geologic Atlas of the Rocky Mountain Region, Rocky Mountain Association of Geologists, Denver, CO, 1972: p. 98.
  18. ^ Yedlin, Deborah (2008-01-16). "Using horizontal drilling techniques in Canada". The Calgary Herald. Retrieved 2008-01-23. 
  19. ^ Holubnyak et al, SPE 141434-MS
  20. ^ Price, Leigh. "Origins and Characteristics of the Basin-Centered Continuous Reservoir Unconventional Oil-Resource Base of the Bakken Source System, Williston Basin" (unpublished paper). Retrieved 2013-02-11. 
  21. ^ Bakken formation Reserve Estimates, which is a July, 2006 Press Release from the North Dakota Industrial Commission which is part of the North Dakota State Government thus in the Public Domain
  22. ^ State of North Dakota Bakken Formation Reserve Estimates (PDF).
  23. ^ a b http://www.valleynewslive.com/story/22118577/north-dakota-oil-boom-getting-bigger
  24. ^ Continental statement: Bakken's giant scope underappreciated
  25. ^ "Brazil’s Oil Frontier: Sub-salt drilling could net billions of barrels". Retrieved December 4, 2011. [dead link]
  26. ^ "Subsalt". Retrieved December 4, 2011. 
  27. ^ Lenny Bernstein (April 30, 2013). "Northern plains site has twice as much oil as previously thought, Interior says". The Washington Post. Retrieved May 1, 2013. "The doubling of the estimate resulted largely because of the first look at the Three Forks Formation in North Dakota, which the Geological Survey said contains 3.73 billion barrels of oil. Its reassessment of the Bakken Formation, which lies above Three Forks, showed 3.65 billion barrels, only a little more than a 2008 USGS estimate. The agency’s conclusion that the formations contain 6.7 trillion cubic feet of natural gas and 530 million barrels of natural gas liquids represented a tripling of previous estimates." 
  28. ^ Stephanie B. Gaswirth; Kristen R. Marra, Troy A. Cook, Ronald R. Charpentier, Donald L. Gautier, Debra K. Higley, Timothy R. Klett, Michael D. Lewan, Paul G. Lillis, Christopher J. Schenk, Marilyn E. Tennyson, and Katherine J. Whidden. "National Assessment of Oil and Gas Fact Sheet Assessment of Undiscovered Oil Resources in the Bakken and Three Forks Formations, Williston Basin Province, Montana, North Dakota, and South Dakota, 2013". Fact Sheet 2013–3013. United States Geological Survey. Retrieved May 1, 2013. "Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered volumes of 7.4 billion barrels of oil, 6.7 trillion cubic feet of associated/dissolved natural gas, and 0.53 billion barrels of natural gas liquids in the Bakken and Three Forks Formations in the Williston Basin Province of Montana, North Dakota, and South Dakota." 
  29. ^ US Energy Information Administration, World shale gas, 17 May 2013.
  30. ^ Secondary recovery will drive the future of the Bakken, Oil and Gas Inquirer, 2013.
  31. ^ US EIA, Crude oil reserves, Table 2, 2013.
  32. ^ Elm Coulee Field.
  33. ^ 2009 Magnolia Petroleum Current activities (PDF).
  34. ^ Jarvie and others, Geology and geochemistry of the Parshall area, Rocky Mountain Association of Geologists, 2011.
  35. ^ Measure offers oil tax rate cut.
  36. ^ Julie Lefever, What's happening at Parshall, North Dakota, North Dakota Division of Mineral Resources, 2 Sept. 2007.
  37. ^ 2006 North Dakota Oil Production by Formation (PDF).
  38. ^ 2007 North Dakota Oil Production by Formation (PDF).
  39. ^ Bakken shale oil, National Geographic Magazine, Mar. 2013.
  40. ^ https://www.dmr.nd.gov/oilgas/stats/historicalbakkenoilstats.pdf
  41. ^ "EOG Resources Inc". Eogresources.com. Retrieved 2011-02-23. 
  42. ^ "Continental Resources Inc". Contres.com. Archived from the original on 23 February 2011. Retrieved 2011-02-23. 
  43. ^ "Whiting Oil & Gas Inc". Whiting.com. 2009-12-31. Archived from the original on 8 February 2011. Retrieved 2011-02-23. 
  44. ^ "Marathon Oil Corporation". Marathon.com. Archived from the original on 25 February 2011. Retrieved 2011-02-23. 
  45. ^ "QEP Resources Bakken.pdf". QEPres.com. Retrieved 2011-10-07. 
  46. ^ Hess Corporation
  47. ^ "Samson Oil and Gas Ltd". Samsonoilandgas.com. Retrieved 2011-02-23. 
  48. ^ Gordon Pitts, Boom lets Saskatchewan plot its own course, Globe and Mail.
  49. ^ Financial Post, Everyone into the Bakken Pool, accessed 18 Sept. 2013.
  50. ^ "Brigham Exploration". Bexp3d.com. Archived from the original on 22 February 2011. Retrieved 2011-02-23. 
  51. ^ Oil Boom Sparks River Fight: Landowners Sue as North Dakota Crude Production Reaches Missouri's Banks April 2, 2012.
  52. ^ US EIA, Takeaway capacity, Today in Energy, 17 Apr. 2012.
  53. ^ Allan Woods, Lac Megantic: train carried mislabeled oil, The Star, 11 Sept. 2013.
  54. ^ Geoffrey Morgan, While Keystone-XL gets all the attention a new Bakken pipeline crosses the border, Alberta Oil Magazine, 6 Mar. 2013.
  55. ^ Bakken shale natural gas flaring tops $100 million each month
  56. ^ US Energy Information Administration, North Dakota sees growth in real GDP, 12 July 2013.
  57. ^ "New Boom Reshapes Oil World, Rocks North Dakota". NPR. 2011-09-25. Retrieved 2011-12-02. 
  58. ^ "Oil Boom Puts Strain On North Dakota Towns". NPR. 2011-12-02. Retrieved 2011-12-02. 
  59. ^ "Affidavit: Abducted Montana Teacher Strangled in Cocaine Frenzy". Reuters. 2012-02-18. Retrieved 2012-02-18. 
  60. ^ Associated Press (2012-04-23). "Bakken oil booms _ and so does crime on the Plains". Fox News. Retrieved 2013-12-10. 

External links[edit]