扩张式随钻扩孔器扩孔机构流场分析与优化  

Flow field analysis and optimization for the reaming mechanism of the expandable underreamer

作　　者：崔淑英 宋刚[2] 田英英[2] 牛庆磊 韩泽龙 赵明[2] CUI Shuying;SONG Gang;TIAN Yingying;NIU Qinglei;HAN Zelong;ZHAO Ming(Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou Guangdong 511458,China;Institute of Exploration Techniques,CAGS,Langfang Hebei 065000,China)

机构地区：[1]南方海洋科学与工程广东省实验室(广州),广东广州511458 [2]中国地质科学院勘探技术研究所,河北廊坊065000

出　　处：《钻探工程》2022年第1期25-33,共9页Drilling Engineering

基　　金：南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项“天然气水合物钻采船单筒双井及大洋钻探技术研究”(编号:GML2019ZD0504);中国地质调查局地质调查项目“深海钻探技术与工程支撑(中国地质科学院勘探技术研究所)”(编号:DD20190585);“XXX先导试验区资源评价与试采(中国地质科学院勘探技术研究所)”(编号:DD20211349);“XXX先导试验区试采实施(中国地质科学院勘探技术研究所)”(编号:DD20190227);中国地质科学院勘探技术研究所项目“深海复杂地层护壁膨胀波纹管现场自动焊接系统与工艺研究”(编号:ZD202002)。

摘　　要：随钻扩孔是大洋钻探跟管钻进工艺的关键技术环节,扩张式随钻扩孔器通过压差控制刀翼的张开和闭拢,扩孔率大,可有效实现套管跟管钻进。设计了悬臂式扩孔器,采用偏置式喷射孔布置对刀翼进行冲刷,运用计算流体力学理论,采用标准k-ε湍流模型,对喷射孔在不同角度和直径下的流场进行模拟分析。模拟结果表明:作用于扩孔刀翼切削齿的流体速度和动压力受喷射孔角度、直径和环空钻井液综合影响;随着喷射孔角度α从40°递增至90°,作用于切削齿的流体速度呈类余弦曲线变化;随着喷射孔直径d从4 mm增大到10 mm,作用于切削齿的流体速度和动压力呈抛物线型变化;综合考虑冲刷效果、加工性能和喷射流体与环空钻井液的相互作用,优选α=70°、d=8 mm。陆地试验和浅海试验证明,扩张式随钻扩孔器结构功能可行,扩孔尺寸满足套管正常跟管钻进需求,优选的喷射孔角度和直径可对刀翼形成良好冲刷,有效防止泥包产生。研究成果可为大洋钻探不同规格的随钻扩孔器设计提供参考依据。Reaming while drilling is a key step of the casing while drilling process in ocean drilling,while the expandable underreamer can effectively realize casing drilling through control of opening and closing of the reaming arms by pressure difference with large reaming size.The cantilever reamer with locking function in place was designed with the offset jet port arrangement for cleaning the arms.The computational fluid dynamics technology and the standard k-εturbulence model were used to simulate and analyze the flow field of the jet ports at different angles and diameters.The simulation results showed that the fluid velocity and the dynamic pressure acting on the cutting teeth of the reaming arms were comprehensively affected by the jet port angle and diameter,and annulus drilling fluid.With the jet port angleαincreasing from 40°to 90°,the fluid velocity acting on the cutting teeth changes in a cosine like curve.With the jet port diameter d increasing from 4mm to 10mm,the fluid velocity and the dynamic pressure acting on the cutting teeth change in a parabola shape.Considering the cleaning effect,machining properties and the interaction between the jet fluid and the annulus drilling fluid,optimization was carried out to determineα=70°and d=8mm.The test over land and at shallow sea showed that the structure and the function of the expandable underreamer were feasible,with the reaming size meeting the requirements of normal drilling with casing,and the optimized jet port angle and diameter achieving good cleaning of the arms to effectively prevent bit balling.The research results can provide a reference for the design of underreamers with different specifications in ocean drilling.

关 键 词：大洋钻探 跟管钻进 扩张式随钻扩孔器 喷射孔 计算流体力学 流场模拟 

分 类 号：P634[天文地球—地质矿产勘探]