基于双层管双梯度深海油气及水合物开发技术研究

Research on Marine Petroleum and Hydrate Development Technology Based on Dual Gradient Drilling of Double-Layer Pipe

为安全高效的开发深水油气和水合物资源,亟需解决深水钻井的窄密度窗口和浅层水合物开采面临的地层漏失严重和开采效率低难题。国内外文献研究表明,国外同心钻杆、海底泵举升和隔水管充气双梯度钻井技术是解决上述难题的有效手段,但其钻井费用昂贵、且对国内技术封锁和垄断。基于此,该研究创新性提出一种基于双层管的双梯度钻井新方法;建立了基于双层管井下泵举升的双梯度钻井井筒压力调控理论及策略;发明了一套双层管双梯度钻井的陆地井实验测试技术。在此基础上,又创新性提出了一种基于双层管双梯度的深水水合物固态流化开发的新工艺,研发了一套天然气水合物射流破碎回收、原位分离回填和泵输一体化开采的工具管串系统,有望突破深水油气和水合物开采的技术和装备瓶颈,为深水油气和水合物的安全高效开采提供具有完全自主知识产权的双梯度钻井技术和装备。

For the safe and efficient exploitation of deep water oil-gas and hydrate resources,it is urgent to solve the problem of serious formation leakage and low mining efficiency of shallow hydrate mining and narrow density window of deep water drilling.Domestic and foreign literature research shows that foreign concentric drill pipe,subsea pump lift and riser inflatable double gradient drilling technology is an effective means to solve the above problems,but its drilling costs are expensive,and technology blockade and monopoly for the domestic.Based on this,a new method of double-gradient drilling based on double-layer pipe is proposed,the theory and strategy of double-gradient wellbore pressure control based on pump lift of double-layer pipe is established,and a set of experimental test technology of double-gradient drilling of double-layer pipe is developed.On this basis,a new technology for solid fluidization development of deep-water hydrates based on double-gradient of double-layer pipe is proposed,and a set of tool string system for gas hydrate jet breakage recovery,in-situ separation backfill and pump transportation is developed,which is expected to break through the bottleneck of deep-water oil and gas and hydrate mining technology and equipment,and provide double-gradient drilling technology and equipment with full independent intellectual property rights for safe and efficient development of deep-water oil and gas and hydrate.