Dr. Julius Tollas

Management Team: Biography

Dr. Julius Tollas

Dr. Julius Tollas, is Co-Chairman (Field Application) of Green Source Holdings LLC, overseeing the company’s focus on its reagent in situ applications.

A native of Hungary, Dr. Tollas received a B.S. and M.S. in Petroleum Geological Engineering from the Petroleum and Gas Engineering University of Bucharest, Rumania (1953).

In 1954, he began working at the Lovaszi Oil Field in Hungary as a Production Geologist. His responsibilities included evaluating which secondary recovery method was the best suited for the ageing oil reservoirs in Hungary. Dr. Tollas designed the first field wide water flood project in Hungary for the Lovaszi field which was also the first commercial oil discovery (c1953) by Esso.

In November 1956, Dr. Tollas had to escape from Hungary because of his activities in the revolution against the Soviet Communism. He eventually ended up in France and then immigrated to the United States in July 1959. He began working for Sinclair Oil Company in West Texas and later in Tulsa, Oklahoma, the company’s headquarters, where his responsibilities were to follow all secondary recovery projects of the company. By redeveloping a twenty year old field in Venezuela, Dr. Tollas was responsible for oil production increasing from 28000 BOPD to 53000 BOPD in one year. While working full time, he received a Ph.D. in Petroleum Engineering from Oklahoma State University.

Dr. Tollas then joined the Exxon Production Research Center in Houston, Texas, working in the Thermal Recovery Section. Dr. Tollas initiated for Exxon the first “Fire Flood” (in situ burning) project at the Talco field in Texas. The following year he was transferred to Exxon’s Reservoir Engineering Section. Notable achievements include the following:

  • Based on a detailed study of gas composition (1972), he found the oil leg (1,100 feet structural closure) of what was originally classified as only a gas reservoir. The Tapis field became the largest oil producing field (peak rate at 150,000 BOPD when fully developed) in the offshore basin of Malaysia;
  • As the project leader, Dr. Tollas studied the optimum development plan for the Prudhoe Bay field in Alaska using the 3D numerical simulator. The State of Alaska required the field to be developed as a single unit. The engineering committee could not agree on the percentage of participation for each company. Therefore, the president of each company took over the negotiation. Dr. Tollas’ team provided Exxon’s U.S. president with three depletion programs in a compressed time frame that gave Exxon a competitive advantage during negotiations;
  • Using Exxon’s 3D thermal simulation program, Dr. Tollas designed the first steam injection pilot project for a viscous oil reservoir (Georgesdorf) in Western Germany. The pilot project was successful, and later it was extended to a large portion of the field; and
  • Dr. Tollas served as the project leader of all reservoir engineering studies, which ultimately increased the recovery of the major oil fields managed by Lagoven Company in Venezuela. The studies were performed on a contract basis between the government of Venezuela and Exxon.

Dr. Tollas was transferred in 1980 to the London office of Esso (E&P) U.K. as a technical advisor and research coordinator. There he convinced Exxon and Shell to change the last phase of the original development program of the Brent field, jointly owned by the two companies. By controlled depressurization of the field, rather than abandoning it at the end of water flooding at high pressure, the 3D numerical reservoir simulation indicated a large, additional amount of gas, condensate and oil recovery. The actual performance of the field with depressurization during the past decade fully justified the $2 billion redevelopment cost.

In 2000, Dr. Tollas returned to the U.S. and retired from Exxon. He became an independent consultant, and remains active as such. In 2007, he formed Bootstrap Holding Group LLC to pursue opportunities in his field which culminated in his co-founding Green Source Holdings the same year.

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