por IADC/SPE Asia Pacific Drilling Technology (1996 : Kuala Lumpur, Malasia) | International Association of Drilling Contractors | Society of Petroleum Engineers (Estados Unidos).
por IADC/SPE Asia Pacific Drilling Technology (1998 : Jakarta, Indonesia) | International Association of Drilling Contractors | Society of Petroleum Engineers (Estados Unidos).
por Drilling Conference (1993 : Amsterdam, Paises Bajos) | International Association of Drilling Contractors | Society of Petroleum Engineers (Estados Unidos).