考虑剪胀性和应变软化的油砂非线性弹性模型  

A Nonlinear Elastic Model for Oil Sands Considering Shear Dilation and Strain Softening

作　　者：高彦芳 任战利 姜海龙[3] 丁帅伟 Gao Yanfang;Ren Zhanli;Jiang Hailong;Ding Shuaiwei(State Key Laboratory of Continental Dynamics,Xi􀆳an 710069,P.R.China;Department of Geology,Northwest University,Xi􀆳an 710069,P.R.China;Mechanical Engineering College,Xi􀆳an Shiyou University,Xi􀆳an 710065,P.R.China)

机构地区：[1]大陆动力学国家重点实验室,西安710069 [2]西北大学地质学系,西安710069 [3]西安石油大学机械工程学院,西安710065

出　　处：《地下空间与工程学报》2023年第1期43-50,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(52204048);陕西省高校科协青年人才托举计划项目(20210413);陕西省教育厅科研计划项目(21JK0937,20JK0843);陕西省自然科学基础研究计划项目(2021JM-407)。

摘　　要：油砂力学模型是石油工程设计与开发的基础。为了更精确地描述油砂的剪胀和应变软化特征,本文提出了一种四参数形式的轴应变偏应力、轴应变体应变模型,对比分析了四参数模型、南水模型和修正的成都科大模型对风城油砂轴应变偏应力、轴应变体应变测试数据的拟合效果,最后对剪胀扩容诱导的绝对渗透率和水的有效渗透率增量进行了预测。研究表明,四参数模型比南水模型、修正的成都科大模型更能合理描述油砂的应变软化、剪胀效应以及体应变演化。根据四参数模型能够更精确地预测剪胀诱导的绝对渗透率以及水的有效渗透率增量,其预测误差比修正的成都科大模型小50%以上。本文提出的四参数模型可以为油砂钻完井及热采数值模拟分析提供关键依据。The oil sands mechanical model is the foundation of petroleum engineering design and development.Describe more precisely the shear dilation and strain softening characteristics of oil sands,this paper proposed fourparameter models about the relations of axial strain-deviatoric stress and axial strain-volumetric strain.The fourparameter models,Nanshui Model,and the modified Chengdu Science and Technology University(CSTU)Model were compared to analyze their fitting effects on the test data of axial strain-deviatoric stress and axial strain-volumetric strain for Fengcheng oil sands.Lastly,the four-parameters models and the modified CSTU Model were used to predict the increase of shear dilation-induced absolute permeability and the effective permeability to water.The research shows that the four-parameter models can describe the strain-softening behavior,shear dilation effect,and volumetric strain evolution much better than the modified CSTU Model.The shear dilation-induced increase of the absolute permeability and the permeability to water can be predicted more accurately according to the fourparameter models,whose prediction error is even more than 50%lower than the modified CSTU Model.The fourparameter models proposed in this paper can provide an important basis for the well drilling,well completion,and the numerical simulation of thermal stimulation in oil sand reservoirs.

关 键 词：剪胀 应变软化 油砂 非线性弹性 四参数模型 

分 类 号：TE345[石油与天然气工程—油气田开发工程]