EXECUTIVE OFFICERS & DIRECTORS Stephen C. Taylor  John W. Chisholm David L. Bradshaw  Kenneth V. Huseman  William F. Hughes G. Larry Lawrence James R. Hazlett Charles G. Curtis Annual Meeting of Shareholders Legal Counsel Independent Auditors Transfer Agent & Registrar Investor Relations Computershare Trust Company, Inc.,  Golden, Colorado Leann M. Conner Natural Gas Services Group Investor Relations Coordinator Telephone: (432) 262-2700 Fax: (432) 262-2701 David A. Thayer Jones & Keller, P.C. 1999 Broadway, Suite #3150 Denver, Colorado 80202 Telephone: (303) 785-1623 Fax: (303) 573-8133 June 13, 2012  8:30 A.M. CDT DoubleTree Hotel 117 West Wall Street Midland, Texas 79701 BDO USA, LLP 333 Clay St., Suite 4700 Houston, Texas 77002 Telephone: (713)-659-6551 Fax: (713)-659-3238 Vice President –Technical  Services Director, Retired, Former  President and Chief Executive  Officer of Curtis One Inc. dba Roll Stair Director , Co-Owner, The  Whole Wheatery, LLC Director, President and CEO,  Basic Energy Services Vice President and Chief  Financial Officer Chairman of the Board,  President and Chief Executive  Officer Director, Founder, Wellogix,  Inc.; President, CEO, Chairman  of the Board, Flotek Industries Director, Oil and Gas Investor,  Former Chairman and CEO, Tipperary Corporation