Mechanical Properties Research On Spanning Submarine Pipeline Of Chengdao Oil Field

As the lifeline of marine oil and gas,the environment of submarine pipeline is very complex.The spanning pipelines have huge influence on the development and production of marine oil an gas.The spanning pipelines are very general in Chengdao oil field,which brings significant source of hidden danger.It is very necessary to research the mechanical characteristics of the spanning pipelines and calculate the maximum allowable span length.In this paper,the research object is level straight spanning pipeline of Chengdao oil field and mechanical characteristics.The spanning pipeline boundary conditions are simplified as simply support and fixed support on both ends.Suspended pipeline is simulated.The modal analysis and the mechanical characteristics of various kinds of pipe diameter in different wave flow state and different span length are carried through.And the suspended length is the most sensitive factor.The analysis of pipe and soil interaction is carried out.The results is compared with the criterion.Considering with the nonlinear soil stiffness,Mechanical characteristics of spanning pipe is analyzed,which the wave and current have been put on,also with the seismic load and inside fluid.The analysis of two dimensional flow around cylinder is carried out by ANSYS Fluent.Base on it,a three-dimensional numerical modal of pipe-soil-fluid is established.The mechanical characteristics of spanning pipeline is analyzed considering fluid-structure interaction.The analysis of the effect of different parameters on the maximum allowable span length is carried out.It is more accurate to consider the soil property and provide the reference to the engineering practice.