The Submarine Pipeline Risk Assessment Research

With the increase development of the ocean oil-gas exploration and production activities during the last few years, the risk issue of submarine pipeline are increasing. The number of impact damage has increased significantly. The pipeline industrial accidents not only severely restricted the oil and gas production, but also brought the life and the property damage to some person even to the country.As pipeline risk assessment technology has strong practically and pertinence, it has been widely applied in the pipeline of mainland and has obtained certain of oceanic oil and gas pipelines that playing a more and more important role in the national economy. Conducted scientifically and rationally risk assessment on the submarine pipeline, which is not only to promote safety in production, but also to comprehensively and effectively enhance the level of safety operation management of the pipeline department. So it is particularly to carry out the risk assessment for the submarine pipeline, to ensure the normal operation of pipelines has a very important significance to the offshore petroleum development of China. The analysis of pipeline, according to actual conditions of the pipeline system and the specific environment in our country to assess and deal with the risk are the main contents of the thesis.Based on the comprehensive investigation and a lot of documents, First of all know about the pipeline engineering system and its development, and analysis the characteristics of the pipeline engineering as well as existing special problems. By the statistical analysis of the pipeline accident, Find out the main failure factors and high risk areas, and so the weak section of the system can be easily found out。 Based on the specific situation of the pipeline, with the analysis and the risk identification, the factor system of the oceanic oil and gas pipelines has been established, and then confirmed weigh by using entropy. In the risk evaluation of the submarine pipeline, many factors have the character of uncertainty, on the basis of analysis about the advantage and disadvantages of random information fuzzy information, gray information and unascertained information, after that introduce the assessment method of unascertained measure which is based on the unascertained mathematics theory, and applies unascertained measure evaluation into the risk assessment of submarine pipeline. According to the unascertained measure theory, set up a model of evaluation index system and constructed some unascertained measure function of each index. According to the sequence in dividing the evaluating space, the incredible recognition rule is established to replace the maximum subordinate recognition rule so as to reduce the misjudgment. At last, the radar chart can provide more information about risk.Finally, with all the studies above, based on the mathematical model of unascertained measure, a software to evaluate the risk grade of the submarine pipeline is established by using the VB programming language, to enhance the efficiency and the accuracy of the evaluation.