Zion Oil & Gas Inc., Dallas, has appointed Victor G. Carrillo as president and chief operating officer.

Carrillo, for 8 years a Texas Railroad Commissioner, is a geologist and geophysicist. He succeeds Bill Ottaviani, who departed Zion Oct. 14, 2011, by mutual agreement.

Liat Roter has joined Zion as a geophysicist in the Israel exploration department. Roter recently completed a master of science in geosciences at the University of Haifa.