Design And Analysis Of TLP Platform Rise Direct Acting Tensioners

With the further development of the oil and gas drilling technology towards the deep ocean filed, the higher requirements are proposed for the deep-water oil exploration equipment due to the complex environment. However,compared to the marine countries, the research of the deep-water exploration equipment in China is still in its infancy stage and far behind marine countries, which is becoming a import restriction factor of building marine country. This project roots in the ministry of industry and information technology of marine engineering equipment scientific research project-the key connection structure technology research of Tension leg platform—the research of key technology and application of top tensioner. The project seeks to narrow the technology gap between our country and marine countries and provide the technological reserve for the TLP equipment design.In this paper, the development status both at home and abroad and the characteristics and operation ability of different forms of tensioners were summarized.And a brief overview about the characteristics of tension leg platform and the riser system was given in this paper.The global designing scheme of the TLP platform rise direct acting tensioners was studied in this paper. Based on the operating features of the direct acting tensioners, the key factors during designing the tensioner system were pointed out, the structure design, the tensioning principle of hydraulic or pneumatic system and the structural layout scheme were determined according to the functional requirements of direct acting tensioners.The working principle was also analyzed detailedly in this paper.In this paper, based on the string mechanics and elastic mechanics theory, with considering the force situation of the risers caused by the internal and external pressure of the water,the calculation method of TLP platform riser top tension was obtained.The tensioning cylinder was designed individually by considering the top tension and the structural characteristics of the tensioner. According to the features of moving type tensioner,the tension ring, the centering device, fittings and recoil control device were designed.The Kinematics and dynamics of direct acting rise tensioners were analysised in this paper.Firstly, the motion response of the TLP platform in the actual area environment was obtained after completion of the modeling and simulation of TLP platform by using the SESAM software. Then the Kinematics and dynamics of tensioner were analysised according to the motion response to get inverse displacement, inverse velocity and inverse accelerated velocity.The lengths of the six hydraulic cylinders,the expansion rate ,the expansion accelerated rate and the relation between the tensioning force changing with time were also obtained by using the ADAMS software.The expression of direct acting tensioners tension and stiffness was obtained after founding the hydraulic system math model. The simulation of hydraulic system was completed by using the appropriate submodel chosen through the AMESim software. The simulation results showed a good agreement with the mathematical analytical results.Furthermore,the overall tensioner is similar to a gas spring,the stability of the tensioner would be improved by changing the system parameters appropriately. After all, the analysis of tensioner could provides references for the optimization design and the hydraulic control system design of the direct acting tensioners.