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Cawley, Gillespie & Associates



Aaron Cawley — Founder

Aaron Cawley

Aaron Cawley, a petroleum engineer since early 1949, received his Bachelor of Science degree in Petroleum Engineering from the University of Texas at Austin. He worked with Honolulu Oil Corporation in Texas both before and after two years of service in the U.S. Navy. He joined Forest Oil Corporation in Midland as a reservoir engineer in the exploration department. His duties included detailed field studies, lease appraisals, work-over evaluations, exploration estimates and pressure maintenance studies. He worked as a petroleum consultant for the firm of Keller & Peterson in Fort Worth for more than five years.

In 1961, Aaron co-founded the firm of Cawley and Harrington, petroleum engineering consultants. In 1973, Clarke Gillespie joined them to form Cawley, Harrington & Gillespie. Then, in 1976, the name was changed to Cawley, Gillespie & Associates. Cawley is a registered professional engineer in Texas, a member of the Society of Petroleum Engineers, the Society of Professional Engineers and the Society of Petroleum Evaluation Engineers.

Clarke Gillespie — Founder

Clarke Gillespie

Clarke Gillespie attended the University of Oklahoma, where he received his Bachelor of Science degree in Petroleum Engineering in 1950 and Master of Petroleum Engineering in 1952. His experience included engineering and geological studies in the principal oil and gas producing areas of the United States. Clarke testified as an expert witness before state regulatory bodies and the Federal Power Commission. From 1951 to 1960, he was employed by Gulf Oil Corporation, becoming Senior Petroleum Engineer in the Fort Worth Production Division. He was in charge of the division’s reservoir engineering laboratory. His duties included evaluation of drilling, sale and acquisition prospects.

Gillespie founded his own petroleum consulting firm in 1960, and joined with Aaron Cawley and Jimmie Harrington in 1973 to form Cawley, Harrington & Gillespie. In 1976, the name was changed to Cawley, Gillespie & Associates. Clarke passed away in 1990.

Cawley, Gillespie and Associates began in 1960. Though our methods and tools have evolved since that time, our values have not. We still provide ethical and independent petroleum engineering services. Our extremely capable team of professionals consists of a broad range of experience and capabilities.

As a petroleum consulting firm, CG&A reviews and evaluates tens of thousands of oil and gas properties on an annual basis worth billions of dollars. Our clients include oil and gas companies, financial institutions and pipeline companies. We evaluate all types of ownership interests, including working interests, net revenue interests, net profit interests and royalties, both conventional and unconventional, in every major basin in the United States.

We have offices in Fort Worth, Houston and Austin. 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.

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.