油层段套管损坏机理研究

【作者】 唐波；

【导师】 练章华；

【作者基本信息】 西南石油学院 ， 油气井工程， 2003， 硕士

【摘要】 本文是在国家自然科学基金项目“基于数值模拟的复杂套管破坏机理研究”(项目批准号：50074025)资助下完成的，本文属该项目的部分内容。 本文主要研究“油层段套管损坏机理”，这也是本文的主题。文中收集了大量的相关文献资料，通过研究分析这些资料，掌握了该领域的研究方法和思路。并在前人研究基础上，本文以弹性理论为基础推导出了油层段套管射孔孔眼对套管抗挤强度的理论公式，同时推导出了在非均匀载荷作用下地层、水泥环及套管组合体应力和位移的理论解析式。通过与有限元法的模拟结果比较以及实验数据证明，文中的理论公式是正确的，为套管柱优化设计提供了简便的方法。 本文的主要创新： 1)推导出了射孔套管抗挤强度的解析式，为分析射孔与套管强度的变化关系提供了简便的方法； 2)推导出了非均匀地层载荷作用下套管、水泥环和地层组合体的应力和位移解析式，并非均匀作用下套管柱优化设计提供了理论依据； 3)研究整个油田区块构造应力场与套管损坏关系，为预测套管损坏提供了可行方案； 本文的研究过程如下： 1)为模拟构造应力场与油层段套管损坏关系，做了大量的岩石单轴抗拉、单轴抗压、三轴试验以及岩石遇水膨胀试验，获得了研究区块岩石的弹性模量、泊松比、内聚力、内摩擦角以及岩石的线膨胀系数，这此数据为本文研究油层段套管损坏机理研究的理论分析和有限元法提供了实验数据。 2)理论分析射孔套管抗挤强度变化及非均匀载荷作用下套管抗挤强度变化； 3)用有限元方法对理论分析结果进行比较分析； 4)用有限元法分析青海东高点跃进二号油田构造应力场对套管损坏分布的影响。更多还原

【Abstract】 This paper was supported by National Natural Science Foundation of China (NSFC) "Study of Mechanism of Casing Failure on the Formation of Complex Mechanics System Based on numerical simulation" (Project No. :50074025).This paper mainly dealt with the Mechanism of Casing Failure on the Oil-deformation. Many of related references were studied in the paper, some methods and ideas are to help our study. The formulas on the perforated casing collapse strength were derived while the casing was perforated. And the stress and displacement formulas on the system of deformation, cement and casing with the non-uniform load were derived. Compared the calculating results by FEM (Finite Element Method), those formulas were true. Those formulas give simple methods to design optimally casing string.New ideas and methods in the paper:1) The formulas on perforated casing collapse strength were deducted, which offereda convenient method to analyze the relationship between casing collapse strength and perforation;2) The stress and displacement formulas on the system of casing, cement anddeformation under the non-uniform load were deducted, which offered the theoretical found for designing optimally casing string;3) The relationship between structure in-situ field of whole oil field and casing failurewere studied, which offered the scheme for the prediction of casing failure. The process of study in the paper:1) For simulating the relationship between the structure in-situ field and the casingfailure in the oil-deformation, the tests of the uniaxial tensile, compress, tnaxial compress and dilatability were made on the samples of the drill cores from deformation of casing failure position in Yuejing II oil field. The elasticity modulus, Poisson’s ratio, cohesion, inner friction angle and linear dilatation coefficient of rock were obtained from those tests, which offered the material data for the theoretical analysis and FEM on the mechanism of casing failure of oil-deformation;2) The varieties of casing collapse strength under the conditions of perforated ornon-uniform load were theoretically analyzed;3) The calculated results by theoretical analysis were compared with those by FEM;4) The casing failure caused by structure in-situ stress field of Yuejing II oil field wasanalyzed with FEM.更多还原