Evolution of Oil Production in the Bakken Formation Julie A. LeFever

Evolution of Oil Production in the Bakken Formation Julie A. LeFever North Dakota Geological Survey

Plays of the Bakken Formation Conventional Bakken (pre-1987) Cycle 1 – Antelope Structure (1950s – 60s) Cycle 2 – Depositional Edge (1970s – 80s) Horizontal Drilling of the Bakken Shale (post-1987) Horizontal Drilling of the Bakken Middle Member (2001 to present)

Conventional Bakken Cycle 1 – Antelope Field Discovery Well Stanolind - #1 Woodrow Starr Initial Potential (536 BO; 0.1 BW) Antelope Field 52 wells; 12.5 million BO; 10 BCF Gas “Sanish Sand” Completion Method

Conventional Bakken Exploration between Cycles Elkhorn Ranch Shell Oil Co. - #41X-5-1 Government Nesson Anticline #1 B.E. Hove IP - 756 BOPD, 3 BWPD Completion Method

Conventional Bakken Cycle 2 – Depositional Limit Stratigraphy & Structure Thin Bakken Multiple Pays Folds, Faults or Both Completion Methods

Horizontal Drilling of the Upper Bakken Shale Meridian - #33-11 MOI Drilled vertical Cored, Logged, Drill Stem Tested Drilled Horizontally - 2603 ft 8 ft - upper Bakken Shale IP: 258 BOPD & 299 MCF gas Cost: 2 million

Learning Curve Meridian -#33-11 MOI 57 days to drill 27 days to drill vertical borehole 12 days to drill horizontal section 2 million 3 set of 10 wells 35 days to drill at a cost 1.08 million End of Play 900,000 (same as a vertical well)

Horizontal Drilling of the Upper Bakken Shale Drilling Methods General Problems Successful well high volumes of oil

Horizontal Drilling of the Bakken Middle Member Richland County, Montana North Dakota

Williston Basin AB SK MB MT ND SD . Co e zi en cK M d an hl ic R . Co MT WY ND Study Area

Richland County, MT Stratigraphy Upper Shale Member Transitional Facies – L7 Lower 2 Devonian Three Forks ies ac of th Li Upper (Productive) Transitional Facies - L1 Lower Shale Member North Mississippian Bakken Formation South Mississippian Lodgepole Formation

Balcron Oil - #44-24 Vaira SESE Sec. 24, T.24N., R.54E. GR Density Porosity upper 1000 0 Bakken Fm. Lodgepole Fm. middle Three Forks Fm. Neutron Porosity

10604.5 ft. SESW Sec. 13, T.23N.,R.56E. AHEL #1 H8 Nevins Richland County, MT Bakken/Three Forks Contact

SESW Sec. 13, T.23N.,R.56E. AHEL #1 H8 Nevins Richland County, MT Middle Member Lithofacies 2

SESW Sec. 13, T.23N.,R.56E. AHEL #1 H8 Nevins Richland County, MT Middle Member Lithofacies 2 (producing facies)

10582 ft SESW Sec. 13, T.23N.,R.56E. AHEL #1 H8 Nevins Richland County, MT Upper Shale/Middle Mbr Contact

Contour Interval BLCS Structure Map Montana North Dakota -57 00 -58 00 -59 00 -60 00 -61 00 -62 00 -63 00 -64 00 -65 00 -66 00 -67 00 -68 00 -69 00 -70 00 -71 00 -72 00 -73 00 -74 00 -75 00 ft

Formation Limits Bakken Formation Upper Middle Lower Prairie Salt Edge ? Montana North Dakota

Contour Interval Isopach of the Bakken Formation Montan a North Dakota 140f 130t 120 110 100 90 80 70 60 50 40 30 20 10 0

Isopach of the Upper Member Bakken Formation 3 2 ft Contour Interval 28 24 20 16 12 8 4 0 Montana North Dakota

Isopach of the Middle Member Bakken Formation 7 0 6 5 Contour Interval 6 0 5 5 5 0 4 5 4 0 3 5 3 0 2 5 2 0 1 5 1 0 5 0 Montana North Dakota ft

Middle Member Porosity Zone Ri ch la nd M cK en zi e Co . Co . Contour Interval 12 10 8 6 4 2 0 Contour Interval: 2 ft. %

Bakken Middle Member Prairie Salt Prairie Salt Edge 7 0 6 5 6 0 Contour Interval 5 5 5 0 4 5 4 0 3 5 3 0 2 5 2 0 1 5 1 0 5 0 Montana North Dakota ft

Bakken Middle Member Prairie Salt Prairie Salt 7 0 6 5 6 0 Contour Interval 5 5 5 0 4 5 4 0 3 5 3 0 2 5 2 0 1 5 1 0 5 0 Montana North Dakota ft

Richland County 80 Producing Fields 1. Red River Fm 2. Madison Fm 3. Bakken Fm 4. Duperow Fm 5. Interlake Fm 20 Fields produce(d) from the Bakken Formation 08/2004

Bakken Formation Richland County, MT Historically – 42 Bakken wells 8 commingled wells Currently – 127 Bakken Producers Horizontals – 92 producers, 1 PNA, 1 Dry Total production 2000 – 2,618,982 BO 2003 – 5,284,378 BO 2004 – 3,275,061 BO (thru August, 2004) 86 Producing Fields, 23 - Bakken Production 08/2004

Drilling & Completion Bakken Horizontals Two laterals to a 1280 spacing unit Well is stimulated with large fracture treatment ( 920,000#, gelled water/sand frac) Cost 2.2 million 500-700 BOPD initially Virtually no water

Horizontal Drilling of the Bakken Middle Member Richland County, Montana North Dakota

Lithofacies of the Middle Member Upper Shale Lithofacies 5 - Siltstone Lithofacies 4 – Interbedded Dark Grey Shale and Buff Silty Sandstone Lithofacies 3 - Sandstone Productive Lithofacies 2 – Interbedded Dark Grey Shale and Buff Silty Sandstone Productive in MT Lithofacies 1 - Siltstone Lower Shale (From LeFever and others, 1991)

Lithofacies 3

SENW Sec. 11, T160N, R95W Conoco, Inc. - #17 Watterud “A” GR Res Producing Zone Upper L2 Facies

Joilette Oil (USA), LLC. #1-17R Robert Heuer Sadler Field Re-entry of a Madison Test (02/13/1981) Bakken Completion 03/05/2004 IP – 87 BOPD, 150 MCF, 142 BWPD Fracture Stimulated Producing Zone – Lithofacies 3

What Do We Know? Rocks Types (Montana North Dakota) Additional Productive Section Lithofacies 3, “Sanish”, lower Lodgepole Limestone Salt Collapse Completion Methods High Production Rates

Conclusions Horizontal Drilling Middle Member Success