Whiting Petroleum Corporation Optimizing Growth by the Bit in the Sanish Drilling Program Bank Presentation August 11, 2010

Forward-Looking Statement Disclosure, Reserve Information and Non-GAAP Measures This presentation includes forward-looking statements that the Company believes to be forward-looking statements within the meaning of the Private Securities Litigation Reform Act of All statements other than statements of historical fact included in this presentation are forward-looking statements. These forward- looking statements are subject to risks, uncertainties, assumptions and other factors, many of which are beyond the control of the Company. Important factors that could cause actual results to differ materially from those expressed or implied by the forward-looking statements include the Company’s business strategy, financial strategy, oil and natural gas prices, production, reserves, impacts from the global recession and tight credit markets, the impacts of hedging on our results of operations, level of success in exploitation, exploration, development and production activities, uncertainty regarding the Company’s future operating results and plans, objectives, expectations and intentions and other factors described in the Company’s Form 10-Q for the three months ended June 30, For additional information, please refer to the Company’s Form 10-Q for the three months ended September 30, The SEC permits oil and gas companies to disclose in their filings with the SEC only proved reserves, which are reserve estimates that geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Whiting uses in this presentation the terms “probable” and “possible” reserves, which SEC guidelines prohibit in filings of U.S. registrants. Probable reserves are unproved reserves that are more likely than not to be recoverable. Possible reserves are unproved reserves that are less likely to be recoverable than probable reserves. Estimates of probable and possible reserves which may potentially be recoverable through additional drilling or recovery techniques are by nature more uncertain than estimates of proved reserves and accordingly are subject to substantially greater risk of not actually being realized by the Company. In addition, Whiting’s production forecasts and expectations for future periods are dependent upon many assumptions, including estimates of production decline rates from existing wells and the undertaking and outcome of future drilling activity, which may be affected by significant commodity price declines or drilling cost increases. In this presentation, we refer to Discretionary Cash Flow, which is a non-GAAP measure that the Company believes is helpful in evaluating the performance of its business. A reconciliation of Discretionary Cash Flow to relevant GAAP measure can be found at the end of the presentation.

Typical 1280 Acre Sanish Well Design 16” Conductor set at 110’ 9-5/8”36 ppf J-55 Casing set at +/-2,100’ 13-1/2” hole (8.8 ppg WBM) 8-3/4” hole (9.7 ppg OBM) Liner Top and KOP at +/-9,500’, 11 0 /100 ft Build Rate 7” 29 ppf L-80 and 32 ppf HCL-80 Casing set at +/-10,400’ 6” hole (up to 9.9 ppg Brine or ppg OBM) 4-1/2” Liner with tools for between 22 to 30 frac stages set at +/-20,000’ TD +/-20,000’

Sanish Field Drilling Days to TD Spud to TD (Days) Pre DWOP/TL 39.2 days Post DWOP/TL 27.2 days thru EOY at 22.3 days

DWOP/TL Meeting StepOnline OperationsOffline Prep Work Logistics/Equip & People Potential Incidents Incident AvoidanceTD DWOP Hrs Act Hrs Delta Hrs 400 Drill 8 3/4" Hole to KOP Install Wear Bushing, PU 8 3/4" BHA and RIH 8 3/4" Bit, Mud Motor w/1.5 ˚ bend, xover, (24) DC, A2Z MWD, 5" DP Prep shakers w/screens Tag cement and test casing to 1000 psi Drill out cement and displace to Invert OBM Line up on full pill tank for displacing w/invert # 2 pump Clean pipes, install wash down gun & diesel bucket at shakers, RU mud bucket & wiper rubbers on floor, change centrifugal pump packingOBM Proper PPE, Provide absorbent material for stairs, walkways, and rig floor Conduct FIT to 10.5 ppg EMW Drill 8 3/4" hole to KOP (9556' appx) Max deviation is 4 deg/RU mud loggers prior to 8500'. H2S equipment on location Sticking Salts Treat stuck pipe w/ FW pills/ BOP drills Circulate hole clean Prep floor for trip out / stage new down hole toolsFloor equipment POOH (wiper trip if logging?) Clean as you go to avoid hazards Stay focused LD BHALD line rigged up & ready Stay aware 1.5 Total

Sanish Wells - Drilling Cost History