Based in Houston formed in 1982, Hollo & Associates, LLC offers oil and gas consulting, acquisition and operating services to the oil industry. We employ a proven and experienced professional team. Our mission is to serve the oil and gas industry in a responsible, efficient and profitable manner.


REUVEN HOLLO, President and Owner

Mr. Hollo has 35 years of experience in the oil industry.  His expertise includes reservoir engineering, acquisition and operation of oil and gas properties.  He established the company as a reservoir engineering consulting firm in 1982. In 1997 he began to acquire and operate onshore and offshore domestic oil and gas properties. The company currently owns properties in Texas, Louisiana, Oklahoma and New Mexico. Mr. Hollo is a graduate of the University of Texas at Austin where he received a PhD in Petroleum Engineering and has completed an executive business program at Harvard University (OPM37).  He is an Adjunct professor at the graduate school at the University of Houston Petroleum Engineering Department.

MARK MULLINIX, Associate and Operations Supervisor

Mr. Mullinix has over 30 years experience in the operation and reservoir management of oil and gas properties.  His experience includes operating onshore and offshore wells in the Permian Basin, Mid Continent, South and East Texas, Williston Basin, Michigan and Offshore Gulf of Mexico.  He has conducted drilling, workover, and stimulation operations.  His experience includes working for Apache, Ranger Oil, Aries Operating, El Paso and Phoenix Exploration. He is a graduate of Texas A&I University (1975) where he received a BS in Engineering.

STACEY MOORE, Accountant

Ms. Moore holds a BBA degree in accounting from the University of Houston-Downtown. Her employment with Hollo & Associates began in 1998.  Ms. Moore maintains accounting, engineering and several other departments throughout in the company.

CARAN CROOKER, Accounting Consultant

Ms. Crooker received her degree in accounting from Texas A & M University in 1976. Ms. Crooker has worked in the oil and gas industry since graduation.  Her employment history includes Superior Oil Company, Natomas North America, Sandefer Oil & Gas and Sandefer Offshore, Gulfstar Energy, Aries Operating, and Phoenix Exploration.

CAROL SUMNER, Information Technology-Software

Ms. Sumner has over 30 years experience in scientific computing and software development, including working on a remote sensing contract for NASA/JSC and on the academic computing staff of Central Oklahoma University. She has also served on the Board of Directors of the Geoshare User’s Group, a petroleum data exchange standards organization. She is a graduate of the University of Alabama.