Prototype Research And Development Of The Subsea Mud Suction Module

In theory, the dual-gradient drilling(DGD) technology can solve the problems associated with deepwater drilling. It has been researched and developed at abroad in 1960s. Among all the implementation methods, only riserless mud recovery(RMR) system obtains a wide range of commercial applications at abroad, and access to significant economic and environmental benefits. The paper presents the research on the subsea mud suction module of RMR, which is supported by the project of"Research on Subsea Mud-lift Drilling Technology (2008ZX0526- 001-12)"sponsored by National Science and Technology Major Special Project. Based on drilling engineering, mechanical engineering and ocean engineering theory, subsea mud-lift drilling technology and structure design and performance analysis of the subsea mud suction module was studied. The main work is summarized as follows:1. Prototype design for mud suction moduleBased on the study of the deep-water drilling in China. According to technical characteristic of subsea mud suction module, working out its design parameters, technical requirements, and design proposal which apply to deepwater drilling in China. Research on the structural design of equipment prototype and draw prototype technical drawings of suction module in 500m and 1500m water depth.2. Research on key technologies of mud suction moduleAccording to Deep-water drilling operation environment in China and technical requirements of subsea mud-lift drilling technology, key technical problems of subsea mud suction module was solved, which including scheme design for rubber, structure design for rotating dynamic seal and it's cooling system, treatment technology for coupling surface in rotating axis, control system for drilling fluid pressure and level in mud suction module, discharge device and locking mechanism for inner rotating assembly. It could provide technical support for realize subsea mud suction module prototype in China.3. Digital prototype development and simulation research of mud suction moduleBy using advanced CAD/CAM engineering software—Pro/E, digital prototype of mud suction module was developmented, In order to meet ensure normal assembly for mud suction module prototype, virtual prototype was assembled and coreected. Based on the design result of mud suction module prototype, simulation research by use of ABAQUS finite element analysis software was conducted. Based on the theory of nonlinear finite element analysis, the feasibility of seal rubber in riserless mud recovery drilling system was verified. Rubber design parameters' influence on the sealing performance and life was researched. Finite element analysis of main components of mud suction module was conducted, and prototype was optimized. It provide technical supports for design and application of subsea mud-lift drilling system and its key equipments.4. Design and Experimental Research of Mud Suction ModuleAccording to final design results of the subsea mud suction module, mud suction module prototype processing technical drawings was drawed, mud suction module prototype was manufactured. Based on the technical characteristics of riserless mud recovery drilling system, laboratory experiment plan was formulated. Working performance of mud suction module prototype was tested, and structural design and design parameters were optimized. It could provide technical support and design basis.