Research On Large Displacement Jack-up System Of Large Deep-water Production Structures

Along with the energy demand of economy development is growing, our countryhas paid more and more attention to the exploitation of marine oil and gas. After about20years’ development, the exploitation of marine oil and gas is increasing andrunning towards to deepwater continuously. The development direction of deep-waterproduction structure is large-scale, comprehensive, and the weight of a singledeep-water production structure has reached tens of thousands of tons. Traditionaloffshore platform installation methods cannot meet these structures’ installationrequirements. Float-over installation is proposed at the historic moment. Float-overinstallation need to jack the structure up to ten to dozens of meters, which cannot bemet by the domestic jack-up technology. Therefore, taking large displacement jack-upsystem of deep-water production structures as the research object, with the purpose offinishing a set of large-scale structure large displacement jack-up technology fordomestic demand, this paper studies mechanical system design technology, hydrauliccontrol technology and electrical control technology, etc. In order to verify thefeasibility of this technology, a large displacement jack-up system model is developedin this paper. The main contend of this paper includes these as follows:(1) All aspects of the system are studied, and put forward the plate-type supportstructure and modular lifting scheme;(2) Build hydraulic synchronizing lifting system mathematical model and thesystem transfer function, and analyse the flow input’s conclusive effect and loadchange’s interference effect to hydraulic synchronism. After the hydraulic systemstability analysis, this paper comes up with a series of measures to improve the systemstability and feedback accuracy.(3) Synchronous control is ascertained to be key technology of hydraulic control.The concept of modular design is introduced creatively during the hydraulic systemdesign. With hydraulic and PLC control technology, the closed-loop control system ofdeep-water production structure large jack-up system is established.(4) Across the analysis of influence factors of hydraulic synchronous accuracy,and eliminating or inhibiting these factors’ methods, the synchronization error controltechnology of deep-water production structure large jack-up system is formed. (5) The large displacement jack-up system model of deep-water productionstructure is developed. The synchronous accuracy of large displacement jackingprocess is verified across model prototype experiment. Draw a conclusion that the lowspeed can improve synchronous accuracy.In conclusion, the large jack-up system for deep-water production structure’sfloat-over installation has great economic and engineering practice significance.