Geologist, Esso Exploration UK Inc., UK. 1966-8.

Geologist, Esso East Atlantic Study Group, Morocco, Senegal and Guinea Bissau, 1968-1971.

Senior Geologist, Area Manager and Chief Geologist (Berkine Basin), Sonatrach, Algeria, 1971-1976.

Staff Geologist, British Gas Corporation, London, 1976-1977.

Senior Staff Geologist, Area Manager and Chief Geologist of British National Oil Corporation/Britoil, Glasgow and Aberdeen, 1977-1986.

Coordinator Subsurface Geology, Geological Laboratory and Regional Studies, and (Acting) Geology Superintendent, Sirte Oil Company (ex-Esso Libya), Marsa al Brayqah, Libya, 1987-1997.

Consultant and Chief Geologist, Exploration Geosciences Ltd, UK, 1997-2000.

Independent consultant and author, 2000-present.