摘要
海洋钻井中由于钻井船或作业平台升沉引起的井筒中工具轴向窜动以及由其导致的环空出砂问题尤为突出,目前也缺少对该类问题的计算分析方法。针对深水(水深>1000 m)浅层(埋深<300 m)水平井防砂充填完井管柱结构,通过建立考虑管壁动摩擦效应的管柱振动模型,利用有限差分法对波浪激励下的管柱振动过程进行分析,以揭示不同条件下井筒中充填工具轴向窜动行为规律,并提出充填工具的结构改进方案。研究结果表明:将钻井船升沉导致的管柱上下往复窜动看作是一种低频振动,考虑管柱-井壁摩擦力和井筒不同位置处的窜动特性的差异性,利用振动模型可以获得相应的位移-时间关系;动-静摩擦力的转换会使得井筒内工具的位移-时间曲线存在零位移的“平台段”;受充填密封筒和“平台段”的影响,位于井筒中部顶部封隔器处的充填工具轴向窜动量最小;通过延长顶封距离和增加中间密封筒长度,并在充填时使用2倍的密封组数,可大幅提升充填至反洗位置的距离,同时增大密封摩阻力约1.5倍,有效降低了因钻井船升沉引起的充填工具位置变化和密封筒脱开问题。测试结果证明该方案有效解决了环空出砂的问题。
The axial movement of tools in the wellbore caused by the heave of drilling vessels or operation platforms and the resultant sand production in the annulus are particularly prominent.Currently,there is also a lack of computational analysis methods specifically addressing these issues.For the sand control packing completion string structure in deepwater(water depth>1000 m)shallow(burial depth<300 m)horizontal wells,a string vibration model considering the dynamic friction effect of the pipe wall was built.Then,the finite difference method was used to analyze the string vibration process under wave excitation to reveal the axial movement behavior of the packing tool in the wellbore under different conditions.Finally,a structural improvement scheme for the packing tool was proposed.The research results show that the reciprocating movement of the pipe string caused by the heave of drilling vessels can be regarded as a low-frequency vibration.Considering the string-wall friction and the variations in movement characteristics at different wellbore locations,the corresponding displacement-time relationship can be obtained using the vibration model.The conversion of dynamic-static friction causes the displacement-time curve of the tool in the wellbore to have a“platform section”with zero displacement.Affected by the packing seal bore and the“platform section”,the axial displacement of the packing tool at the top packer in the middle section of the wellbore is the smallest.By extending the top packer distance,increasing the seal bore length and utilizing twice the number of seal stacks during the packing operation,the achievable distance for packing to the backwash position is significantly increased.Concurrently,the seal friction resistance is raised by approximately 1.5 times.This effectively mitigates issues of packing tool position variation and seal bore disengagement caused by the heave of drilling vessels.The test results show that the scheme effectively solves the problem of annular sand production.
作者
杜卫刚
董祥伟
刘延鑫
庞振力
曹智
宋国强
Du Weigang;Dong Xiangwei;Liu Yanxin;Pang Zhenli;Cao Zhi;Song Guoqiang(CNPC Offshore Engineering Company Limited;College of Mechanical and Electronic Engineering,Shandong University of Science and Technology;College of Mechanical and Electrical Engineering,China University of Petroleum(East China))
出处
《石油机械》
2025年第12期100-108,128,共10页
China Petroleum Machinery
基金
中国石油天然气集团有限公司项目“天然气水合物生产性试采技术装备研究和试验示范”(2021DJ4902)
中国石油集团海洋工程有限公司课题“适用于非均质储层泡沫树脂防砂剂及配套工具研究”(202402-0101)。
关键词
海洋钻井
深水浅层
防砂充填
管柱力学
轴向窜动
有限差分法
结构优化
offshore drilling
deepwater shallow layer
sand control pack
string mechanics
axial movement
finite difference method
structural optimization
