Nankong well drilling and coring technology for Songke1 well

Songke 1 well,the first cretaceous continental scientific drilling well in the world,is the key research issue of cretaceous important geological events of earth surface system and greenhouse climate change project in national basic research program and the first program of cretaceous scientific exploration and drilling accomplished by scientists out of Europe.Nankong well in Songke1 well is designed to core continuously until 945 m,which is complicated,new and with high requirements.Mao 206 well drilled in Daqing oilfield since August,2006,has taken measurements such as optimizing well structure, silicon drilling fluid system,and so on.Meanwhile,feasible technology scheme explores effective approach to improving coring efficiency,increasing scientific exploration and drilling velocity,which ensures the construction proceeding smoothly and each index achieving scientific requirements.Mao 206 well cores 104 cylinders continuously,having 946.83 m footage and 99.73% harvesting rate of coring,which accomplishes the original plan 80.5 d in advance and creates the highest efficiency in Chinese continental scientific exploration and drilling.