[1]CNPC Engineering Technology R & D Company Limited;
Beijing 102206;
China;
[2]School of Petroleum Engineering;
China University of Petroleum;
Qingdao 266580;
China;
[2]School of Petroleum Engineering;
China University of Petroleum;
Qingdao 266580;
China;
[3]School of Petroleum Engineering;
China University of Petroleum (Beijing);
Beijing 102249;
China;
[2]School of Petroleum Engineering;
China University of Petroleum;
Qingdao 266580;
China;
[2]School of Petroleum Engineering;
China University of Petroleum;
Qingdao 266580;
China;
[2]School of Petroleum Engineering;
China University of Petroleum;
Qingdao 266580;
China;
organoclay-free; oil-based drilling mud; rheology modifier; emulsifier; fluid loss reducer; weak gel; reservoir protection;