Traditional dendroclimatology research is based on the statistical correlation between tree-ring chronology and modern o......

PDC钻头是钻井工程提速增效主要手段之一。常规全面钻进PDC钻头破岩方式,对软地层刮切,对中硬地层刮切为主,剪切为辅,生成的岩屑颗......