深水钴井导管喷射下入深度确定方法

Determination method of conductor setting depth using jetting drilling in deepwater

关键词:  深水钻井  导管  下人深度  承载能力  时间效应

Key words:  deepwater drilling  conductor  setting depth  bearing capacity  time effect

摘要:

通过分析深水钻井导管的受力特征,在土力学和桩基理论的基础上，重点考虑时间效应对承载力的影响,提出 一种通用的深水钻井导管喷射下人深度确定方法。利用该方法可以合理地确定导管下入深度，减少设计的盲目性 并节省钻井成本。结果表明:大直径导管的承载能力较大,所需下入深度较小;随着恢复时间的增加，导管承载力逐 渐增强，所需下人深度可以相应减小，但是过长的时间间隔将增加钻井成本,要根据实际情况权衡确定;承载力增长 系数的选取对设计结果有较大影响,应根据区域试验数据合理选取。

Abstract:

Based on the analysis of conductor mechanical characteristics, jetting technique, geotechnics and pile theory, a universal determination method of conductor setting depth considering time effect was proposed. The method can reduce conductor design blindness and drilling cost. Results show that the conductor with a large diameter has larger bearing capacity and needs less setting depth. With set-up time increasing, the bearing capacity of conductor enhances gradually, and the setting depth required could decrease. But longer set-up time could cause drilling cost increasing, the set-up time should be determined according to actual situation. The growth factor of bearing capacity has considerable influence on the result，and it should be selected on the basis of block experimental data.