Attributable to Certain
Leasehold and Royalty Interests
December 31, 2009
RYDER SCOTT COMPANY, L.P.
TBPE Firm Registration No. F-1580
/s/ Fred P. Richoux
Fred P. Richoux, P.E.
Executive Vice President
September 17, 2010
1000 Kensington Tower
7130 South Lewis
Tulsa, Oklahoma 74170-2500
At the request of Unit Corporation (Unit), Ryder Scott Company (Ryder Scott) has conducted a
reserves audit of the estimates of the proved reserves as prepared by Unit’s engineering and geological staff
based on the definitions and disclosure guidelines contained in the United States Securities and Exchange
Commission Title 17, Code of Federal Regulations, Modernization of Oil and Gas Reporting, Final Rule released
January 14, 2009 in the Federal Register (SEC regulations).
The reserves audit conducted by Ryder Scott was completed on January 15, 2010. This third party
letter report presents the results of our reserves audit based on the guidelines set forth under Section 229.1202(a)
(7) and (8) of the SEC regulations. The estimated reserves shown herein represent Unit’s estimated net reserves
attributable to the leasehold and royalty interests in certain properties owned by Unit and the portion of those
reserves reviewed by Ryder Scott, as of December 31, 2009.
The properties reviewed by Ryder Scott incorporate 622 reserve determinations and are located in the
states of Arkansas, Colorado, Kansas, Louisiana, Mississippi, Montana, North Dakota, New Mexico,
Oklahoma, Texas, and Wyoming.
The proved net reserves attributable to the properties that we reviewed account for 81 percent of the
total proved net liquid hydrocarbon reserves and 65 percent of the total proved net gas reserves based on
estimates prepared by Unit as of December 31, 2009. The properties that we r