Exhibit 24.1 POWER OF ATTORNEY KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints J. Larry Nichols, H. Allen Turner and Marian J. Moon, and each or any one of them, his true and lawful attorney-in-fact and agent, each acting alone, with full powers of substitution and resubstitution, for him and in his name, place, and stead, in any and all capacities, to sign any or all amendments (including post-effective amendments) and supplements to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agents, each acting alone, full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, each acting alone or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof. /s/ John W. Nichols /s/ J. Larry Nichols _______________________________ _____________________________ John W. Nichols J. Larry Nichols Chairman of the Board and Director President, Chief Executive Officer and Director /s/ William T. Vaughn /s/ Danny J. Heatly ________________________________ _____________________________ William T. Vaughn Danny J. Heatly Vice President Finance Controller /s/ Luke R. Corbett /s/ Thomas F. Ferguson ________________________________ ____________________________ Luke R. Corbett Thomas F. Ferguson Director Director /s/ David M. Gavrin /s/ Michael E. Gellert ________________________________ ____________________________ David M. Gavrin Michael E. Gellert Director Director /s/ Tom J. McDaniel /s/ H.R. Sanders, Jr. ________________________________ ___________________________ Tom J. McDaniel H.R. Sanders, Jr. Director Director /s/ Lawrence H. Towell _______________________________ Lawrence H. Towell Director