Investigation Of Structural Design And Analysis Method For Umbilical Cable

Umbilical cable is one of the important equipments in underwater production system which is the popular developing model in the deep-sea oil and gas exploitation. It is the connected channel between floating platform and subsea well or manifold, and provides electrical or hydraulic power, monitoring control signal and related chemical injection for underwater production system. The structure of umbilical cable is composed of a variety of optical or electrical components with helical winding and non-adhesive form. Under functional and environmental loads, nonlinear contact, friction and slip may occur between the components, which make the structural design and analysis of umbilical cable very difficult. Because the exploiting equipment industry for offshore oil and gas started late, our country is lack of the key technologies of design, analysis and manufacture of the umbilical cable. Entirely depending on imported umbilical cables restricts seriously the exploitation of deep-sea oil and gas fields.Design and analysis method for umbilical cable are investigated in this paper. First, the research status of umbilical cable is surveyed systematically, and the loading and failure characteristic and process for structural design and analysis of umbilical cable have been investigated. Based on functional and structural characteristic of components, design methods for key components such as hydraulic tubes, fillers and armor are presented. Meanwhile, considering of the symmetrical principle for cross-sectional layout suggested in specification, a measurable indicator-arm of equivalent stiffness is presented and symmetry is described by mathematical expression, which make design of the cross-sectional layout carried out conveniently. Then, the mechanical responses for different components arrangements are discussed. On the basis of that, combining theory analysis and numerical stimulation, a method is presented out to check the structural mechanical properties of umbilical under different working conditions. Cross-section mechanical properties are analyzed and compared under different modeling method of filler, and a better method to model filler is suggested. Finally, key components and the cross section layout of umbilical cable which firstly is manufactured in our country are designed and analyzed based on the above structural design and analysis method. The structural mechanical properties are checked and design evaluation is given. The research result is of certain motivation for independent designed capacity in exploiting equipment industry for offshore oil and gas. This research of the dissertation is sponsored by Hi-Tech Research and Development Program of China (863Program,2009AA09Z301-2) and China Postdoctoral Science Foundation (20110491521)...