... hand, improper handling of the pressure may cause the stuck drill and the screw to fail in advance. 2. Formation mineral components (1) Upper stratum: Above the Guantao Formation, the clay minerals are mostly imonian (I/S), I/S is 70%˜58%, the Yimeng interlayer is disordered...

... adheres to the clay mineral surface and prevents ion exchange, therefore providing pore throat protection and deterring damage to the formation matrix. The treatment was used during underbalanced drilling projects where each well/project had two to three laterals of low permeability. It was successfully...

... to the large amount of clay minerals, while one outcrop sample exhibits the strong shear wave anisotropy only and the other one is almost isotropic. Subsurface samples have lower values of Young's modulus, peak stress, Mohr-Coulomb failure parameters and unconfined compressive strength than outcrop samples...

... Abstract The use of water-based drilling fluids to drill shale formations causes wellbore stability problems as a result of the reaction of water with clay minerals. When it comes in contact with water, clay starts to react, swell and/or disperse leading to shale disintegration and sloughing...