1. School of Petroleum Geology, Faculty of Engineering University of Zulia Maracaibo 4002 Venezuela
2. PDVSA, Exploration and Production Activities Av. 5 de Julio Maracaibo 4002 Venezuela
3. Center for Research in Sustainable Chemistry (CIQSO) University of Huelva 21006 Huelva Spain
4. Independent Petroleum Geochemistry Consultant Madrid 28410 Spain