水平井井身结构设计之压漏校核新方法

Leakage check method of casingprogram design for horizontal wells

目前水平井已成为高效开发油气藏的一项重要技术,由于水平段地层压力剖面的特殊性,在钻井过程中随着井眼的延伸,水平段易发生井漏,直接影响了施工效率与钻井成本。基于水平井钻井过程中水平段的受力特点,结合水平段地层压力剖面特性,提出了一种压漏校核新方法,该方法将环空动态压力计算纳入水平井井身结构设计中进行考虑,逐段进行环空动态压力计算与校核,通过寻找压漏临界点确定套管下深,并根据钻井实践经验优化水平井井身结构,提高了水平井井身结构设计的科学性。该方法应用于水平井井身结构设计中,将有助于保障水平井钻井的安全性,提高施工效率,降低钻井成本。

Horizontal wells have become an important technology for effectively developing oil and gas at present. With well- bore goes forward, well leakage is likely to occur on horizontal section because of the particularity of formation fracture pressure for horizontal wells, which affects the drilling efficiency and drilling cost. Considering the characteristics of formation fracture pressure and force analysis of horizontal section during drilling, a new leakage check method was developed with consideration of the annular dynamic pressure and practical experience of drilling. This method was safer, more efficient and more cost-saving than conventional design methods.