August 8, 2005

Tulsa, Oklahoma . . . Unit Corporation (NYSE – UNT) announced today that its wholly owned
subsidiary, Unit Drilling Company, has signed a purchase and sale agreement to acquire seven drilling rigs from Texas Wyoming Drilling, Inc., a Texas-based privately-owned company. The purchase price of the acquisition is $32 million, $20 million to be paid in cash and $12 million to be issued in stock. The acquisition is anticipated to close on or before August 31, 2005.

Of the seven drilling rigs, five are currently operating under contract and two are in the process of refurbishment and are anticipated to be operational before the closing date. The rigs are active in the Barnett Shale area of North Texas. Six of the seven drilling rigs are mechanical, with one being a diesel electric rig, and range from 400 to 1,700 horsepower.

Mr. Larry Pinkston, Unit’s President and Chief Executive Officer, said, “This acquisition will
create a new market area for Unit, which is an area of Texas that has extensive drilling activity. We expect the acquisition to be immediately accretive to annual earnings in the range of 11 to 13 cents per share at current dayrates. We believe this area of operations will be beneficial to the growth of the company and will expand our fleet to 111 drilling rigs at the close of the acquisition.”

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Unit Corporation is a Tulsa-based, publicly held energy company engaged through its subsidiaries in oil and gas exploration, production, contract drilling and natural gas gathering and processing. Unit’s Common Stock is listed on the New York Stock Exchange under the symbol UNT. For more information about Unit Corporation, visit its website at http://www.unitcorp.com.