【摘要】 非常规油气逐渐成为开发重点，但初次压裂后储集体未完全打碎，产量衰减快，需重复压裂提高采收率。膨胀管井筒重构二次压裂可操作性好，目前已成功应用于中外油田，但存在密封件失效、无法封隔老射孔眼问题，影响剩余产量挖潜。采用室内测试与比选的方式明确了适用于膨胀管密封件的材料本构模型，考虑原射孔毛刺为橡胶损伤失效主要诱因，建立了膨胀管-橡胶-毛刺冲击碰撞损伤失效有限元分析模型，基于应变、应力分别编写了橡胶失效判定准则，明确了橡胶失效演变过程，提出了损伤量归一化处理方法，进一步明晰了不同因素下橡胶损伤失效规律，最终形成了密封件损伤特征值与主控因素关系图版，基于其分别从地面作业与井下处理限定条件两方面对膨胀管井筒重构作业提出了建议，即控制水平段管柱下入速度≥4 min/柱，毛刺高度在3.0 mm内。更多还原

【Abstract】 Unconventional oil and gas has become a major focus of development. However, after initial fracturing, the reservoir is not fully fractured, leading to rapid production decline and necessitating repeated fracturing to improve recovery. Refracturing in a new wellbore which reconstructed by solid expandable tubular is highly operable and has been successfully applied in both domestic and international oil fields. However, issues such as seal failure and the inability to seal old perforations hinder the potential for remaining production. Physical property testing and comparisons was used to determine the appropriate material constitutive model for expansion tube seals. Considering the original perforation burr as the primary cause of rubber failure, a finite element model was developed to analyze the impact of expansion tube-rubber-burr collisions on damage. Rubber failure criteria based on strain and stress were developed, the evolution of rubber failure was analyzed, and a method for normalizing damage volume was proposed. The rubber failure behavior under various factors was further analyzed. Finally, a relationship chart was established between the characteristic value of seal damage and its main controlling factors. Based on these findings, recommendations for expansion tube wellbore reconstruction operations were provided, focusing on two aspects: controlling the horizontal section string entry speed to ≥4 min/column and maintaining burr height below 3.0 mm.更多还原