中文摘要：

针对复杂地质条件下套管外载荷多变的特点,建立了基于遗传算法的套管柱优化设计方法。应用遗传算法理论,确定染色体编码方式、初始种群的产生方法、染色体评估函数及遗传操作,建立基于遗传算法的套管柱优化设计模型,从而克服了传统套管柱设计方法在复杂地质条件下套管柱强度设计中运算过程复杂,无法兼顾套管成本与风险因素的缺点。对普光气田某井套管柱进行的设计验证情况表明,该方法设计结果准确可靠,既提高了套管柱可靠性,又有利于降低成本。该项研究为复杂地质条件下优化套管柱设计提供了新的方法。

英文摘要：

In light of changeable external load of casing in complex geologic conditions, the optimized method to design casing string on the basis of genetic algorithm was established. The genetic algorithm theory was applied to determine the coding mode of chromosome, production method of initial population, and evaluation function of chromosome and genetic operation. Thus, the optimized design model for casing string on the basis of genetic algo- rithm was established to overcome the defects of complex calculation process and neglect of casing costs and risk factor in the traditional design method of casing string strength concerning complex geologic conditions. The design verification of some casing string in Puguang Gasfield shows that the design method is accurate and reliable. It improves the reliability of casing string and helps to reduce the costs. The present study offers the method to optimize the design of casing string in complex geologic conditions.