固井水泥环对套管抗挤压性能的分析与研究

发布时间：2018-05-09 11:22

本文选题：套管 + 水泥环缺陷　；参考：《山东大学》2015年硕士论文

【摘要】：随着国家经济的不断发展,对能源的需求越来越大。作为国家经济发展的重要能源之一的石油,变得越来越重要。目前没有一种能源可以替代石油,新的油区尚未勘探出来之前,能否改进原有产区的开采技术,提高当前石油产区的采收率,将直接影响到国家未来的发展。对于老井而言,为了提高油气采收率,经常用到射孔、酸化、压裂、高压注水等增产措置,这对固井质量提出了很高的要求。如果固井质量不够好,复杂的地质条件下,油气井会产生较多不利因素,比如管外面冒油、气、水,使得井下压力泄露,油气产量下降；破坏井壁,发生井下坍塌；井眼报废,重新投资打新井。这些都将大大提高开采成本。本文在前人工作的基础上,基于弹性力学的基本原理,建立了套管-水泥环-地层模型,结合拉梅问题基本解,推导了套管-水泥环-地层系统在均匀载荷下的受力。水泥环的弹性参数为固井过程中可人工控制的因素,本文在结合前人的工作,采用有限元法,建立了套管-水泥环-地层的有限元模型,结合某油田实例,分析了非均匀地应力下水泥环的弹性模量和泊松比对套管强度和刚度的影响。水泥环缺陷经常出现,对套管也会造成应力集中等不利影响,本文还针对该问题,建立有限元模型,分析了水泥环缺陷的位置和跨度两个因素对套管强度的影响,并给出了改进的方法。
[Abstract]:With the development of national economy, the demand for energy is increasing. As one of the important energy sources of national economic development, oil has become more and more important. At present, there is no energy to replace oil. Before the new oil area is explored out, it will directly affect the future development of our country whether we can improve the production technology of the original oil producing area and enhance the oil recovery factor of the current oil producing area. For old wells, in order to improve oil and gas recovery, perforation, acidizing, fracturing and high pressure water injection are often used to increase oil production, which puts forward high requirements for cementing quality. If the cementing quality is not good enough and the geological conditions are complex, oil and gas wells will produce many unfavorable factors, such as oil, gas and water coming out of the pipe, which will cause the downhole pressure to leak, and the oil and gas production will decrease; the wellbore will be destroyed and the downhole will collapse; and the borehole will be abandoned. Reinvest in new wells. These will greatly increase the cost of mining. On the basis of previous work and based on the basic principle of elastic mechanics, a casing cement ring-stratum model is established in this paper. Combined with the basic solution of Lamey problem, the stress of casing cement ring-formation system under uniform load is deduced. The elastic parameters of cement ring are the factors that can be controlled manually in cementing process. In this paper, the finite element model of casing, cement sheath and formation is established by using finite element method in combination with the previous work, and an oil field example is given. The influence of elastic modulus and Poisson ratio on casing strength and stiffness under inhomogeneous ground stress is analyzed. Cement sheath defects often occur, which will also cause adverse effects such as stress concentration on casing. In this paper, a finite element model is established to analyze the influence of the location and span of cement sheath defects on casing strength. The improved method is also given.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE931.2

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