APRIL 1, 2003 – SAN ANTONIO, TEXAS – Pioneer Drilling Company (AMEX: PDC) today announced that Chesapeake Energy Corporation has invested $20 million in the Company. Chesapeake Energy Corporation has purchased 5,333,333 newly issued Pioneer Drilling common shares at $3.75 per share, or 24.6 percent of Pioneer’s outstanding common shares.

Michael E. Little, Pioneer Drilling’s Chairman and Chief Executive Officer, stated, “We are very pleased that Chesapeake Energy shares in our vision for the continued growth of Pioneer Drilling Company and the increasing demand for land rigs and natural gas in the United States. We are extremely well served by having a partner on our team with the industry experience and the success of Chesapeake Energy. Their confidence in our future has positioned us to strengthen our balance sheet and be better capitalized for further growth.”
Pioneer Drilling will use the proceeds to retire a $6 million term loan, pay remaining balances on a National 110UE 1500 HP SCR rig being built for the Company and a Cabot 1200 land rig being purchased from an entity in Trinidad. The remaining proceeds will be used for future growth opportunities.

Pioneer Drilling Company provides contract land drilling services to independent and major oil and gas operators drilling wells in central, south and east Texas. The Company’s fleet currently consists of 24 land drilling rigs that drill in depth ranges between 10,000-18,000 feet, with an additional 1500 HP SCR land rig scheduled for delivery on May 1, 2003, and a Cabot 1200 rig expected to be delivered in the Summer of 2003.

This press release contains various forward-looking statements and information that are based on management’s belief as well as assumptions made by and information currently available to management. Forward-looking information includes statements regarding the Company’s anticipated growth, demand from the Company’s customers, capital spending by oil and gas companies and the Company’s expectations regarding its new rigs. Although the Company believes that the expectations reflected in such forward-looking statements are reasonable, it can give no assurance that such expectations will prove to have been correct. Such statements are subject to certain risks, uncertainties and assumptions, including, among other matters: general and regional economic conditions and industry trends; the continued strength or weakness of the contract land drilling industry in the geographic areas where the Company operates; decisions about onshore exploration and development projects to be made by oil and gas companies; the highly competitive nature of the contract land drilling business; the Company’s future financial performance, including availability, terms and deployment of capital; the continued availability of qualified personnel; and changes in governmental regulations, including those relating to the environment. Should one or more of these risks materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those expected. These risks, as well as others, are discussed in greater detail in the Company’s filings with the Securities and Exchange Commission, including the Company’s annual report on Form 10-K for the fiscal year ended March 31, 2002 and subsequent Form 10-Q’s.