深水钻井井口吸力桩稳定性计算和校核方法  

Stability calculation and verification method for conductor suction piles in deepwater drilling

作　　者：李舒展 杨进[1] 朱国倞 黄熠 王宁[3] 万宏宇 马会珍 LI Shuzhan;YANG Jin;ZHU Guojing;HUANG Yi;WANG Ning;WAN Hongyu;MA Huizhen(College of Safety and Ocean Engineering,China University of Petroleum(Beijing),Beijing 102249,China;Zhanjiang Company,CNOOC,Zhanjiang 524057,Guangdong,China;Offshore Oil Engineering Co.,Ltd.,Tianjin 300450,China;Shandong Qilong Offshore Petroleum Steel Pipe Co.,Ltd.,Dongying 257092,Shandong,China)

机构地区：[1]中国石油大学(北京)安全与海洋工程学院,北京102249 [2]中海石油(中国)有限公司湛江分公司,广东湛江524057 [3]海洋石油工程股份有限公司,天津300450 [4]山东祺龙海洋石油钢管股份有限公司,山东东营257092

出　　处：《石油钻采工艺》2024年第1期13-24,共12页Oil Drilling & Production Technology

基　　金：国家自然科学基金企业创新发展联合基金重点支持项目“深水含水合物海洋土与水下桩基耦合作用及失稳机理研究”(编号:U22B20126);国家重点研发计划项目“深水生产系统泄漏检测及应急处置技术与装备”(编号:2022YFC2806100);国家工业和信息化部高技术船舶科研项目“水下油气生产系统全生命周期可靠性保障技术体系研究”子课题(编号:2018GXB-01-03-005);海南省重大科技计划项目“深海高效环保膨胀型表层导管研发”(编号:ZDKJ2020021)。

摘　　要：深水松软土质下,传统喷射法安装的表层导管在钻井阶段存在下沉和倾斜的风险。为了提升深水钻井水下井口的稳定性,提出了井口吸力桩表层建井的方法,开展了吸力桩下入深度和稳定性分析。基于桩基承载理论和广义Winkler地基梁模型,建立了井口吸力桩稳定性理论模型,并通过有限元方法和有限差分法研究了井口吸力桩稳定性特征及影响因素。以南中国海某井工程参数为依据,对井口吸力桩稳定性开展理论计算,与有限元计算结果进行对比,竖向极限承载力误差为4.23%,最大水平位移误差为6.0%,最大弯矩误差为2.96%,印证了计算结果的准确性。在钻井工况极限载荷作用下,相比于传统表层导管,井口吸力桩竖向承载力提升了43.91%,水平位移减少了63.21%,抗弯安全系数是前者的24.5倍。分别对井口吸力桩施加不同水平位移和弯矩,结果表明水平载荷对横向稳定性影响较为显著。井口吸力桩具有很高的竖向承载力和横向承载力,显著提高了水下井口的稳定性,研究结果为其在深水松软土质中表层建井提供了理论依据。In soft soil conditions of deepwater,there exist risks of sinking and tilting of surface conductors traditionally installed by jetting during the drilling process.To enhance the stability of subsea wellheads in deepwater drilling,a method of surface casing installation using conductor suction piles was proposed,and the insertion depth and stability were analyzed.Based on the pile foundation bearing theory and the generalized Winkler foundation beam model,a theoretical model for the stability of subsea suction piles at the wellhead was established.The stability characteristics and influencing factors of subsea suction piles were studied using finite element methods and finite difference methods.Based on engineering parameters of a well project in the South China Sea,theoretical calculations on the stability of the subsea suction piles were carried out,which were then compared with finite element calculations.The comparison show that the vertical ultimate bearing capacity error was 4.23%,the maximum horizontal displacement error was 6.0%and the maximum bending moment error was 2.96%,confirming the accuracy of the calculation results.Under extreme loading conditions during drilling operations,compared to traditional surface conductors,the vertical bearing capacity of subsea suction piles was increased by 43.91%,horizontal displacement was reduced by 63.21%,and the bending safety factor was 24.5 times higher.Different horizontal displacements and bending moments were applied to the subsea suction piles,showing that horizontal loads had a significant impact on lateral stability.Subsea suction piles have high vertical and lateral bearing capacities,significantly improving the stability of subsea wellheads,providing a theoretical basis for surface casing installation in soft soil conditions of deepwater.ions of deepwater.

关 键 词：深水钻井 井口吸力桩 竖向极限承载力 横向极限承载力 稳定性校核 有限元分析 

分 类 号：TE52[石油与天然气工程—油气田开发工程]