A Study on the Stability of the Borehole in Shale, in Extended-reach Drilling
Baohua Yu1, Chuanliang Yan1, Deli Gao1,2, Jinxiang Li3
CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.1, pp. 57-78, 2012, DOI:10.3970/cmes.2012.089.057
Abstract Shale is easy to hydrate and often causes a collapse of the borehole during drilling, especially in drilling extended-reach wells (ERW). In order to solve the problem of collapse of the shale, the changinges in the mechanical properties of shale, as affected by hydration and water absorption, are studied in this paper, through experiments. The relationships between the mechanical properties of shale and the water content are established. The borehole-stability models, which couple chemistry and mechanics are established, by considering the anisotropy of swelling, based on the experimental results. The stability of shale in the… More >