title: Effect of DGPS failures on dynamic positioning of mobile drilling units in the North Sea.
abstract: Basic features of differential global positioning system (DGPS), and its operational configuration on dynamically positioned (DP) mobile offshore drilling units in the North Sea are described. Generic failure modes of DGPS are discussed, and a critical DGPS failure which has the potential to cause drive-off for mobile drilling units is identified. It is the simultaneous erroneous position data from two DGPS's. Barrier method is used to analyze this critical DGPS failure. Barrier elements to prevent this failure are identified. Deficiencies of each barrier element are revealed based on the incidents and operational experiences in the North Sea. Recommendations to strengthen these barrier elements, i.e. to prevent erroneous position data from DGPS, are proposed. These recommendations contribute to the safety of DP operations of mobile offshore drilling units.
authors.affiliation: Scandpower Risk Management China Inc., Towercrest Int. Plaza, Chao Yang District, Beijing, China. haibo.chen@scandpower.com.cn
authors.forename: Haibo
authors.initials: H
authors.lastname: Chen
authors.forename: Torgeir
authors.initials: T
authors.lastname: Moan
authors.forename: Harry
authors.initials: H
authors.lastname: Verhoeven
mesh_terms: D000062:Accidents, Occupational; D019544:Equipment Failure Analysis; D019652:Extraction and Processing Industry; D040362:Geographic Information Systems; D006801:Humans; D009659:North Sea; D010578:Petroleum; D017751:Safety Management
chemical_list: D010578:Petroleum