中文摘要：

与浅水钻井相比,深水钻井井漏的处理更加困难,预防井漏尤为重要.针对南中国海深水区域井漏频繁发生的现状,调查了已钻井发生井漏的复杂情况,对漏失现状进行了分析,包括易漏失时的作业工况及漏失性质研究等;结合南中国海深水典型的漏失案列,分析了本地区井漏的主要原因：深水压力窗口小、ECD 过高等;并根据南中国海深水井漏失的原因和特点,提出了相应的的预防和处理措施,希望对后续该区域深水井井漏的预防及处理提供一定的参考.

英文摘要：

Compared with the case in shallow water drilling, the handling of lost circulation in deepwater drilling is more dififcult, making it particularly important to prevent lost circulation. To address the status of frequent lost circulation in deepwater of the South China Sea, the complex conditions of the drilled wells are investigated and the leakage status is analyzed, including the operating condi-tions for easy leakage and the nature of leakage. In combination with the typical leakage cases in the South China Sea, the main causes for lost circulation in this area are analyzed: small deepwater pressure vessel, extremely high ECD, etc. prevention and treatment measures are proposed according to the causes and characteristics of deepwater wells leakage in the South China Sea in hope of providing some reference for the prevention and treatment of future deepwater wells lost circulation in this area.