As a petroleum consulting firm, CG&A reviews and evaluates hundreds of thousands of oil and gas properties on an annual basis worth billions of dollars. Our clients include oil and gas companies, financial institutions, midstream/pipeline companies and individual investors. With diversified experience in oil and gas producing properties throughout North America and around the globe, CG&A’s proficient team of reservoir engineers and geologists integrate geological, geophysical, engineering and economic data to produce high-quality reserve estimates and economic forecasts.

  • Putting our clients first, since 1960
  • Office locations in Fort Worth, Houston, and Austin, Texas, USA
  • 30+ Engineers, Geologists and Technical Analysts
  • Worldwide producing basin experience, unconventional and conventional
  • Approved by all major banks, key regional banks, and private equity firms
  • Deep experience with SEC, SPE-PRMS and COGEH guidelines and reporting


  • Todd Brooker
  • Zane Meekins
    Executive Vice President
  • Tom Hardman
    Chief Technical Officer
  • Mary Ann Giordano
    Chief Financial Officer
  • Ken Mueller
    Vice President
  • Gus Presas
    Vice President
  • Matt Regan
    Vice President
  • Kellie Jordan
    Senior Engineer
  • Jonathan Schmit
    Senior Engineer
  • Josh Passman
    Senior Engineer


The birth of our firm goes back to 1960, when Clarke B. Gillespie started his own petroleum engineering consulting firm (1960) and Aaron Cawley and Jimmie D. Harrington also started their own firm (1961). The merger of Clarke B. Gillespie, Inc. and Cawley & Harrington, Inc. in February 1973 led to the formation of Cawley, Harrington and Gillespie, Inc. The name was later changed to Cawley, Gillespie & Associates, Inc. in February 1976 when Harrington left the firm, and A. W. Augustson and Walter J. Evans joined the firm. The roots of the organization go back much further.

In the late 1930’s or early 1940’s, a Fort Worth based geological consulting firm Cummins, Berger, Pishney and Brinkerhoff was providing services to the petroleum industry. Mr. Brinkerhoff lived in Houston and ran their offices there. In the late 1940’s or early 1950’s, this firm separated and Ralph Cummins continued to have an office in Fort Worth. Walter Berger became an independent consultant. Charles Pishney became associated with Burton Atkinson in the early 1950’s, and they later separated in the early 1960’s. Clarke Gillespie and Rush Vann shared offices with Atkinson and worked on joint projects together, and Gillespie later started his own firm in 1960.

In 1951, Wally Keller and L. F. Peterson left Stanolind Oil & Gas to form the engineering firm of Keller and Peterson in Midland. Jimmie D. Harrington and A. W. Augustson were employed by this firm in 1953 and shortly thereafter, their offices were moved to Fort Worth. Additional major hires by Keller and Peterson were Henry F. Calloway in 1954, Aaron Cawley in 1956 and Walter J. Evans in 1958. In 1972, Peterson left the firm of Keller and Peterson which became Keller and Augustson. Cawley and Harrington left Keller and Peterson in 1961 and formed Cawley & Harrington in Fort Worth which was merged with Gillespie in 1973. Harrington left the firm in 1976, and Keller and Augustson was dissolved when Augustson and Evans became owners in Cawley, Gillespie & Associates, Inc.

Cawley Gillespie & Associates, Inc. has continued business uninterrupted through the decades and today still delivers professional, ethical and reliable engineering and geological services to the petroleum industry.