摩擦系数与摩阻系数及其控制方法探讨  

Discussion on Friction/Drag Coefficient Control Methods

作　　者：梁奇敏[1,2] 杨永刚 何俊才[4] 张翼[5] LIANG Qimin;YANG Yonggang;HE Juncai;ZHANG Yi(CNPC Research Institute of Petroleum Exploration and Development,Beijing 100083,China;China University of Geosciences(Beijing);No.3 Oil Production Plant of Petrochina Changqing Oilfield Company,Yinchuan,Gansu 750006,China;The 2nd Drilling Company of Daqing Drilling Engineering Company,Daqing,Heilongjiang 163413,China;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580,China)

机构地区：[1]中国石油勘探开发研究院 [2]中国地质大学.北京 [3]长庆油田分公司第三采油厂 [4]大庆钻探工程公司钻井二公司 [5]中国石油大学(华东)石油工程学院

出　　处：《钻采工艺》2019年第1期11-13,I0001,I0002,共5页Drilling & Production Technology

摘　　要：大位移井井下管柱的摩阻和扭矩一直是限制大位移井延伸的主要因素。"摩擦系数"和"摩阻系数"是两个不同的概念,这两个概念对大位移井钻进和下套管时的摩阻计算至关重要。摩擦系数,在大位移井中,是指管柱下入过程中与井下已有套管的内壁或者与裸眼地层之间接触,钻井液作为界面产生的一个系数,分为动摩擦系数和静摩擦系数两种;摩阻系数则是一个综合性系数,它包含摩擦系数以及所有如"键槽"、"缩径"等附加阻力引起的等效摩擦系数。在计算摩阻时应该采用摩阻系数而非摩擦系数,而摩阻系数受井眼状况等因素的影响在管柱不同位置都不同,难以准确确定。阐述了目前大位移井摩阻系数的确定方法,以及钻进和下套管过程中常用的降摩手段。文章的探讨结果对大位移井的设计和施工有一定的指导意义。Extended reach well technology represents the most advanced drilling technology in the world nowadays,and the down-hole drag and torque are always being the two key factors which restrict the extension.It is stated herein that the friction coefficient and drag coefficient are two different concepts,those two concepts are very important to do torque and drag calculation for extended reach well drilling and casing running.In the extended reach wells,friction coefficient is caused by tubing or string contacts with down-hole casings or open hole during the running process and the drilling fluid being the interface.It includes two kinds,sliding friction coefficient and static friction coefficient.Drag coefficient is a comprehensive coefficient,which includes the friction coefficient and the equivalent friction coefficients caused by all additional resistances caused by dogleg or undergauging.It is the drag coefficient rather than the friction coefficient been used for drag calculation during the drilling and casing running process,and drag coefficient is influenced by many factors such as borehole conditions,which is varied along the drill string and hard to be determined.The classic formula for drag calculating is illustrated,and the commonly used measures to reduce drag of extended reach wells during the drilling and casing running process are expounded.The results in this paper can offer certain guiding significance for the design and construction of extended reach wells.

关 键 词：钻井 大位移井 钻具 摩擦系数 摩阻 

分 类 号：TE52[石油与天然气工程—油气田开发工程]