发明名称 TOP DRIVE APPARATUS
摘要 A top drive system for wellbore drilling operations, the top drive system including a main shaft having an upper shaft seal system with a raised platform for supporting the seal system. The top drive may also have a shroud for covering the seal(s), and contaminants may flow down from the seals, since the seals are raised by the platform.
申请公布号 EP2118428(A1) 申请公布日期 2009.11.18
申请号 EP20080709668 申请日期 2008.03.03
申请人 NATIONAL OILWELL VARCO, L.P. 发明人 WELLS, LAWRENCE, E.;FOX, PRESTON, R.;YENZER, DARRIN, LYNN
分类号 E21B3/02;E21B19/16 主分类号 E21B3/02
代理机构 代理人
主权项
地址