Whiting Petroleum Corporation (NYSE: WLL) announced today that it has commenced a public offering of $1.8 billion aggregate principal amount of senior notes due 2019 and senior notes due 2021, subject to market and other conditions. Whiting expects to use the net proceeds from this offering to repay all of the debt outstanding under Whiting Oil and Gas Corporation’s credit agreement, to fund its $260.0 million acquisition of Williston Basin assets, to retire its $250.0 million of outstanding 7.0% Senior Subordinated Notes due 2014 on or prior to their maturity on February 1, 2014 and for general corporate purposes including capital expenditures. Wells Fargo Securities, LLC, J.P. Morgan Securities LLC and BofA Merrill Lynch are the joint book-running managers for the offering. The offering is being made only by means of a prospectus supplement and accompanying prospectus, which are part of an effective shelf registration statement Whiting filed with the Securities and Exchange Commission, copies of which may be obtained from Wells Fargo Securities, LLC by calling (800) 326-5897, J.P. Morgan Securities LLC by calling (866) 803-9204 or BofA Merrill Lynch at 222 Broadway, 11 th Floor, New York, NY 10038, Attention: Prospectus Department, or at firstname.lastname@example.org. An electronic copy of the prospectus supplement and accompanying prospectus are available from the Securities and Exchange Commission’s website at www.sec.gov. This press release does not constitute an offer to sell or the solicitation of an offer to buy these securities, nor will there be any sale of these securities, in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such jurisdiction. About Whiting Petroleum Corporation Whiting Petroleum Corporation, a Delaware corporation, is an independent oil and gas company that explores for, develops, acquires and produces crude oil, natural gas and natural gas liquids primarily in the Rocky Mountain, Permian Basin, Mid-Continent, Michigan and Gulf Coast regions of the United States. The Company’s largest projects are in the Bakken and Three Forks plays in North Dakota and its Enhanced Oil Recovery field in Texas. The Company trades publicly under the symbol WLL on the New York Stock Exchange.