2012 Williston Basin Petroleum Conference

1. 2012 Williston Basin Petroleum Conference Number of Completion Stages – Does it Matter Bismarck, ND May 22 - 24, 2012 Jim Thompson Bakken D&C Manager Marathon Oil Corporation

2. Topics of Discussion • Bakken completion stages • Effect on IP and cumulative production • Optimum number of stages • Other considerations • Proppant types and selection criteria • Function • Selection • Transport • Messenger word of thanks • Drilling & Completion Team • SS Team • Ahmad Salman • UT Team • Steve Baumgartner • Marathon Oil Corporation

3. 16” 9-5/8” 7” 9000+’ 6” Hole Bakken Completion Stages • Marathon Oil Corporation • Single Stage Completions • OH • Uncementedpreperforatedliner • Crosslinked polymer , linear gel, and/or slickwaterfracs • Diverter slugs or balls UBS MBS LBS

4. Bakken Completion Stages • Marathon Oil Corporation

5. 16” 9-5/8” 7” 9000+’ 6” Hole Bakken Completion Stages • Marathon Oil Corporation • Multi Stage Completions • Plug and Perf • Frac Sleeves • Rapid adoption of 10 stage Sleeve Technology • ¼” graduated ball seats • Linear Gel and Crosslinked polymer fracs UBS MBS LBS

6. Bakken Completion Stages • Marathon Oil Corporation

7. Bakken Completion Stages • Evolved to 20 stage sleeve technology with 1/8” graduated ball seats • Decreased spacing between stages • Increased amount of stimulated rock volume (SRV) • Versus 10 stage • Progression to 40 stages continued with move to 1/16” graduated ball seats • Number can be tweaked to operators preference with mixing of sleeves and plug and perf typically referred to as hybrid completion • Marathon Oil Corporation UBS MBS LBS

8. Bakken Completion Stages • Marathon Oil Corporation

9. Bakken Completion Stages • Marathon Oil Corporation

10. Bakken Completion Stages • Marathon Oil Corporation

11. Bakken Completion Stages • Marathon Oil Corporation

12. Bakken Completion Stages • Marathon Oil Corporation

13. Bakken Completion Stages • Marathon Oil Corporation

14. Bakken Completion Stages • Marathon Oil Corporation

15. 2006 – 2011 Dunn County Middle Bakken Wells 2006 – 2007 Open Hole Wells 2006 – 2007 Open Hole Completion Wells Average Proppant Density (lb/ft): 71 • Marathon Oil Corporation 2008 Staged Wells 2008 Stage Completion Wells Average # of Stages: 6 Average Proppant Density (lb/ft): 144 2009 Staged Wells 2009 Stage Completion Wells Average # of Stages: 9 Average Proppant Density (lb/ft): 171 2010 Staged Wells 2010 Stage Completion Wells Average # of Stages: 19 Average Proppant Density (lb/ft): 268 2011 Staged Wells 2011 Stage Completion Wells Average # of Stages: 20 Average Proppant Density (lb/ft): 228 2011 staged wells cumulative oil production based on extrapolation Data obtained from NDIC public information.

16. Bakken Completion Stages • Marathon Oil Corporation • Conclusions • Number of completion stages does have an effect on IP and cumulative production during first year • Increases stimulated rock volume • Other considerations which may effect optimum number of stages • Geology or rock quality • Understand natural fractures to determine vertical vs horizontal growth dominance • Flowbackpractices • Conservative or Aggressive choke management • Be consistant to evaluate proper number of stages • Frac design per stage • Fluid volumes • Proppant volumes • Proppant type • Consistency is key to determine effect of varying the number of stages • Change one variable at a time keeping others the same • Understand cost implications of each variable for well economic considerations

17. Proppants and Selection Criteria 2012 Williston Basin Petroleum Conference Bismarck, ND May 22 - 24, 2012 Jim Thompson Bakken D&C Manager Marathon Oil Corporation

18. Proppant Types and Selection Criteria • Marathon Oil Corporation %Fines per API/ISO procedure

19. Proppant Types and Selection Criteria • Marathon Oil Corporation

20. Proppant Types and Selection Criteria • Marathon Oil Corporation • ProppantFunction • Keep the created fracture (length and height) open • Provide conductivity contrast to accelerate flow to the wellbore • Proppant Selection • Cost • Proppant pack conductivity – minimum 500 md-ft • Size – as large as you can place with frac design • Effective Closure Stress on Proppant= Minimum Horizontal Stress – Fracture Face Flowing Pressure (Pressure in the Producing Propped Fracture) • Fracturing fluid damage – slick water, linear gel, cross link fluids • Crush test • Less than 10% fines generated at maximum closure stress • Predict-K • Tool to predict proppant pack conductivity of planned fracture treatments • Evaluate conductivity of what can be placed, 2 lb/ft2 of 20/40 versus 2.5 lb/ft2 of 30/50, etc.

21. Proppant Types and Selection Criteria • Marathon Oil Corporation • ProppantSelection (cont’d) • Proppantpack conductivity over the life of well • Production damage (scale, salt, fines, etc.) • Proppant degradation from stress cycling • Embedment into formation face • ProppantTransport • Larger proppant provides higher conductivity but may be more difficult to place • Settling rate increases in proportion to the diameter squared • Bridging • Perforation diameter should be six times larger than proppant diameter • Pumping hydraulic fracture width should be three times larger than proppant diameter

22. Questions Thank You