【摘要】 根据提高承压能力封堵理论,分析了有效封堵天然裂缝和诱导裂缝产生楔形效应的过程,针对楔形封堵,建立了考虑温度变化的井周应力数学模型。通过某井的实例计算,分析钻井液冷却对楔形封堵效应的结果表明,裂缝壁面受到钻井液的冷却作用时,井周应力降低,同时可能产生微裂缝,导致封堵效果变差。建议使用非渗透处理剂或膨胀性、固化堵漏材料,使之形成不渗透封堵层,降低钻井液或滤液的冷却作用,提高堵漏成功率。更多还原

【Abstract】 Based on the theory regards improving compressive strength of sealing/plugging,the stress cage caused by effective sealing of natural fractures and induced cracks is analyzed,and a mathematical model for calculting circumferential stress is set up considering temperature changes. It has been used to calculate for one well,the results suggest drilling fluid cooling on the fracture or crack surfaces will cause reduction in circumferential stress,and induce micracracks,leading to poorer sealing/plugging. it is recommended to adopt impermeable additives or swellable solidifying LCM to form impermeable sealing to reduce the fluid cooling effects and improve the success ratio of lost circulation control.更多还原