Patrick G. Sullivan, a long-time government official whose studies for the Treasury Department foretolr the natural gas and petroleum shortages, died May 25 at Arlington Hospital following a chest operation. He was 59.

Mr. Sullivan, an attorney and engineer, began his long career in the government after World War II when he entered the U.S. Geological Survey. He consequently worked for the Federal Power Commission, simultaneously earning a law degree at George Washington University. He also worked for the Atomic Energy Commission before joining the law firm of Hogan and Hartson, where he specialized in energy issues.

Mr. Sullivan, a native of Globe, Arizona, earned a B.S. Degree in Minning Engineering and Metallurgy at the University of Texas at El Paso. He worked for U.S. Steel in Lorain, Ohio, before entering the Navy in 1942. He rose from ensign to lt. commander at the U.S. Naval Proving Ground in Dahlgren, Va., where he worked on the design and construction of expanding facilities.

Mr. Sullivan was a member of the Federal Power Bar, the District of Columbia Bar, and the Registered Professional Engineers of Texas.

He is survived by his wife, Virginia A. of the home; a son, Patrick, G. Jr., of McLean, Va.; a sister, Mrs. Jack Niland of El Paso, Texas; and a brother, John Francis Sullivan of Santa Monica, Calif.

The family request that expressions of sympathy be in the form of contributions to the American Cancer Society.