A COUPLED MULTIPHYSICS FE MODEL FOR THE EVOLUTION OF STRESSES AROUND A BOREHOLE IN SHALES
The evolution of borehole stresses in shale is profoundly affected by the drilling-induced intricate links between transport processes (e.g. hydraulic flow, thermo-osmosis, thermo-filtration, and diffusion of ions), physical change due to compressibility and chemical reactions, and chemical change (e.g. ion exchange, and swelling pressure). A coupled thermal-hydraulic-mechanical-chemical (THMC) model is presented to evaluate these complex intricate links and their impact on the evolution of borehole stresses in shale. ·The model incorporates non-isothermal free and forced convection of a single component fluid into a non-boiling thermoelastic medium. The four-way simultaneous coupling between the THMC quadruplet is currently linear but no restriction is placed on incorporating material nonlinearities. The coupled PDEs are solved in space and in time by using finite element method. The model is validated against analytical solutions for the coupled hydraulic-thermal-mechanical responses of a borehole in low permeability rocks under non-isothermal conditions and applied to a typical example. In this example, we account for fully coupled thermo-hydro-mechanical-chemical effects. In particular, we explore the influence of thermo-, and chemical-osmosis in driving the magnitude of thermal stresses interior to the borehole wall.
Jinchang Sheng J Liu D Elsworth WC Zhu Jian Zhao Baoyu Su
College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, P.R.China School of Oil & Gas Engineering, The University of Western Australia Department of Energy and Geo-Environmental Engineering,Pennsylvania State University
国际会议
南京
英文
683-688
2006-05-22（万方平台首次上网日期，不代表论文的发表时间）