Safety Evaluation Of Drilling Platform Towage In Bohai Sea Based On Extension Evaluation Model

With the development of offshore oil industry,the rig accidents increase gradually.Accident history shows that accidents of jack-up drilling platform towage often bring huge property losses and significant casualties.There are too many jack-up drilling platforms for oil exploration and exploitation in Bohai Sea,and there is a certain risk of drilling platform towage.The traditional navigation safety assessment of towage operation can’t reflect a certain safety degree of towage in quantitatively,So it is necessary to make a safety evaluation of towage.There is a safety evaluation of certain towage using the Extension Evaluation Model in this paper.First of all,there is a comprehensive analysis of towage safety factors.According to the classification of environmental factors,ship and equipment factors,personnel and management factors,24 influencing factors of towage security are analyzed one by one,and quantification method of each factor is given.Secondly,according to the expert questionnaire,by using the Integrated Recursive Method,12 indexes are selected and the evaluation index system is formed.The grade is divided and the evaluation standard is determined.Then,the Extension Evaluation Model is brought in towage safety evaluation.The towage safety evaluation matter-element is established,and the classical domain,the joint domain and the reviewing matter-element is determined.The combined weight is made up by Analytic Hierarchy Process weight and Extension weight.Dependency and grade rules are formed,and the Extension Evaluation Model is built completely.Finally,three towage instances are selected.According to calculation,vertical comparison and horizontal comparison,this evaluation model is verified.The evaluation results are the security grades,the security grade tendencies and the security grade order of the three towage instances,which are consistent with actual situation according to the vertical comparison and the horizontal comparison.In the end,this paper gets the following conclusions:this evaluation method is feasible and effective;Towage safety factors should be comprehensive analyzed,and the index system should be discarded the dross and kept the finer part;The combined weight is subjective and objective as well as dynamic and static;The core of Extension Evaluation is to determine the classical domain,the joint domain and the dependent function.