“…The rheological properties, filtration properties and lubrication properties of drilling fluid with inhibitor, tackifier, filtrating agent or lubricant such as AV (apparent viscosity), PV (plastic viscosity), YP (yield point), FL (API filtration) and TG (friction coefficient), were evaluated using a viscometer (ZNN-D6S, Hetongda Co. Ltd, Qingdao), medium-pressure filtration instrument (GJSS-B12K, Haitongda Co. Ltd, Qingdao) and viscosity coefficientin strument (Qingdao Hetongda Co. Ltd, Qingdao) according to the formulas in Chinese National Standard GB/T 16783.1-2006, followed by the thermogravimetry, mud ball experiment and SEM were carried out after the formula of solid-state drilling fluid was determined. [11][12][13][14][15][16][17][18][19][20][21][22][23]…”