【作者】 郭建平；

【导师】 樊太亮；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2009， 博士

【摘要】 我国稠油资源分布广泛,在稠油热力开采过程中,套管大量损坏造成国家每年不得不投入大量资金用于打新井和修复套管损坏井,热采井套管损坏防治技术一直是制约国内陆上稠油油藏开发的技术难题之一。在热采环境下,影响套损的因素更加复杂,研究热采环境下的套损机理并提出合理而有效的防损措施对于减少损失、提高稠油开采经济效益意义重大。目前对单场作用下的套损机理研究已经比较成熟,石油领域对多场耦合的研究也已经有了一定的进展,但是还没有人真正提出合适的根据多场协同耦合作用研究套管损坏的方法。本文基于ANSYS有限元分析软件,以管柱力学、岩石力学、传热学、数值分析和有限元等理论为指导,通过建模和求解,提出了井筒附近多场耦合下的热有限元分析方法,对热采井筒周围多场协同作用规律进行了有益的探索,取得了如下主要成果:(1)在建立模型时对一些复杂的套损影响因素进行简化处理,重点突出研究协同作用效应的目的,建立了井筒周围地应力作用模型、井筒隔热传热模型及由套管、水泥环和地层组成的井筒周围多场耦合协同作用的套损模型。(2)以研究协同效应为目标进行多场的序惯耦合分析,研究了多场耦合模型的求解问题,主要用APDL工具进行了二次程序开发,提高了计算效率。(3)对套管和油管之间的环空仅在温度场模型中考虑其传热性,在力学处理上把其舍去减少了一个非常复杂的非线性力学问题,而且没有影响蒸汽温度边界对套管应力的影响。(4)以具体的算例进行了计算,分析了各种因素对套损的影响,根据计算结果,对套管设计和防护提出了有价值的建议。更多还原

【Abstract】 Thick oil resources are widely distributed in China. During thermal recovery processes, a large number of casing damages occur, and as a result, massive funds have to be invested in drilling new wells or repairing the damaged ones. Prevention technology for thermal recovery wells is always one of the problems that get in the way of thick oil development onshore in China. In the environment of thermal recovery, influencing factors for casing damage are more and more complex, the study on mechanism of casing damage is very important for improving economic benefit of thick oil recovery.At present, study on casing damage mechanisms under the action of single field is already more mature. Study on multi field coupling in the field of petroleum development has also made new progresses. But, proper method for studying casing damages according to multi-field coupling effects has been put forward.In this thesis, using the finite element analysis software of ANSYS and under the guidance of pipe-string mechanics, rock mechanics, heat transfer, numerical analysis and theory of finite element analysis, and by models building and solving, multi-field coupling finite element analysis method is put forward to analyze the mechanical behaviors of the system near the well bore underground. Useful exploration for the cooperative effects law of multi-field coupling is also made in this thesis. Several results of the thesis are summarized as follows:1. Some complex influencing factors of casing damages are simplified in the models building, and cooperative effects are studied mainly. Ground stress interaction model near the well bore under ground, heat insulation and transfer model for well bore and cooperative multi-field coupling model for system made up of casing, cement sheath and formation near the well bore are built.2. In order to study the cooperative effects, sequential multi-field coupling analysis is made in this thesis. The solution methods of the model are also studied. Through the second order programming using APDL (ANSYS Parametric Design Language), the calculation efficiency is greatly improved.3. Mediums in the annulus are not definite, and its diathermancy is only considered in the thermal insulation and transfer model. There is no necessary considering it in solving the complex mechanical problems in the total model. By this practice, the calculating is simplified and the effect of boundary temperature on the thermal stress is not influenced.4. Specific examples were calculated through the methods above, the influence of all sorts of factors on casing damages is analyzed. And valuable suggestions for casing design and protection are also put forward.更多还原