稠油油藏热-流体-力学耦合模型研究及应用

在稠油油藏开发中，由于原油黏度高一般采用注蒸汽开采。基于连续介质力学理论，考虑了热对流的影响，建立了蒸汽注入条件下对地层压力、变形和有效应力定量评价的改进的热-流体-力学耦合数学模型；应用全隐式顺序Galerkin有限元数值解方案对注蒸汽井热-流体-力学耦合过程进行了数值模拟。计算结果表明，由于地层流体高温膨胀引起的高压力，会导致位移、变形，甚至地层结构破裂；温度对地层破裂形态的影响显著。研究表明，这个改进模型比传统模型更加准确、实用，可以用于蒸汽注入速率优化和油藏、地质、热-流动力反应、地应力水平等综合作用效应研究。

Study on a coupled thermal-hydraulic-mechanical model in heavy oil reservoir exploitation and its application

In order to solve the high viscosity problem of the crude oil,the steam stimulation technology is generally adopted in heavy oil reservoir exploitation.Based on the continuum mechanics theory,an improved thermal-hydraulic-mechanical coupling model which considers the influence of heat convection is established to quantitatively evaluate the formation pressure,deformation and effective stress under steam injection conditions.The Galerkin finite element method with the fully implicit and sequential algorithm is used to simulate the thermal-hydraulic-mechanical coupling process around the injection well.The results show that the high pressure which is caused by the higher thermal expansion of fluid may lead to displacement,deformation or even failure of structure;and the temperature has a great influence on the fracture geometry of the formation.The study indicates that this enhanced model is more exact and practical than the classic method and can be applied to optimizing the steam injection rate,investigating the combined effects of the reservoir,geology,thermal-hydraulic response,in-situ stress,etc.