【作者】 盛金昌； 廖秋林； 刘继山； 速宝玉；

【Author】 SHENG Jinchang, LIAO Qiulin, LIU Jishan, SU Baoyu (College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098 China, School of Oil & Gas Engineering, The University of West Australia, Perth Australia)

【机构】 河海大学水利水电工程学院； 中科院地质研究所； 西澳大利亚大学石油天然气工程系；

【摘要】 钻孔过程中的渗流-变形-温度多场耦合作用非常复杂,它对井壁稳定分析具有重要意义。目前对于这一问题的研究已有一些研究成果,但复杂条件下的数值解答成果还不是很丰富。本文将在有关文献的基础上,首先建立一组饱和多孔岩体介质瞬态的流、固、热三场全耦合方程组(其中包括固体变形、能量传输、流体流动三个相互耦合的过程,多物理场之间的交叉耦合还包括材料性质与独立变量之间的耦合关系),然后利用 FEMLAB软件(基于偏微分方程组的多物理过程模拟工具)作为平台。分析了钻孔过程的流同热耦合作用过程, 计算结果反映了耦合作用对井壁围岩应力的重要影响。本文的计算结果与解析解进行了比较,结果非常吻合, 证明了本文耦合模型及求解方法的正确性。更多还原

【Abstract】 Coupled porothermoelastic response of a wellbore is very complicate in petroleum engineering, which is one of the key problems for wellbore stability. In the paper, a coupled porothermoelastic model is presented in a saturated linear thermoelastic medium, which incorporates cross-coupled fluid flow equation, energy conservation equation and mechanical equilibrium equation with many cross-coupling terms. A series of constitutive relations and cross-coupling relations between material properties and independent variables are defined in the model. A 2-D coupled porothermoelastic problem of a wellbore with known analytical results is simulated by using a FEMLAB-based simulator, in which pore pressure, displacements and temperature can be solved simultaneously. Cooling-induced pore pressure, tangential and radial stresses distribution along the radial direction away from the wellbore for various times are discussed in this example. The results reveal that coupled processes have significant effects on the stresses and wellbore stability. The good agreement of the numerical results with the analytical solutions indicates that the coupled porothermoelastic model and the FEMLAB’s based simulator are credible.更多还原