The Study On The Key Technology In The Phase Of Deep-water Pipeline Installation

There is a growing tendency that the exploration of the offshore oil and gas steps to the deep ocean. The pipeline project of deep water, as the key phase of the offshore oil and gas operations, plays a vital role in transportation. Due to the irregular seabed terrain, the current scouring and the uneven soil, there often occurs free span. How to deal with and solve the deep-water pipeline span in the project has become a common problem of submarine pipeline in installation phase.This paper sums up the causes and types of the span in deep water and discusses the influence of submarine pipeline span in structural strength, stability and fatigue strength. Besides, taking the submarine pipeline free span length as key factor, this paper companies and analyses the calculation method on the maximum allowable span length from the static and dynamic angle separately.Starting from the DNV-OS-F101 submarine pipeline standard, this paper elaborates the contents about the method of load and resistance factor and pipeline buckling. Based on the proposed approximate methods in DNV-RP-F105, this paper propagates calculation software of the allowable span length of submarine pipeline in engineer.Subsea processing operation is an effective measure to solve the pipe span. The article summarizes the basic method of subsea processing operations commonly used at present. Besides, this paper combines with the specific circumstances of subsea treatment, so as to establish the index weight determination in AHP and fuzzy comprehensive evaluation model for subsea treatment.This paper put forward a set of integrated span analysis method, which considering the problem of submarine pipeline in installation phase. It has some guiding significance to the actual project.