Abstract: Geological risk assessment of the oversea hydrocarbon exploration project plays a significant role in investment and decision-making of oversea exploration projects. In order to indicate differences of geological conditions and risk from different projects as objectively as possible, with respect to features of oversea hydrocarbon exploration projects, this paper discusses principles of geological risk assessment on oversea hydrocarbon exploration projects and puts forward a new quantitative risk assessment method combining geological characteristics with degree of prospecting. Furthermore, the parameters system and the assignment standards system for geological risk assessment are established in this paper. It provides a new and applicable method for management and decision-making of oversea hydrocarbon exploration projects

Key words: geological risk assessment, oversea exploration project, assessment parameters system, assignment standards