水平井下套管摩阻分析研究

Analysis of casing friction in horizontal well

套管下入过程中大钩载荷的预测是成功的关键因素之一,水平井由于其特殊的井眼轨迹,在下套管的过程中摩阻比常规井大。因此,准确地预测套管下入摩阻对水平井固井的设计和施工具有重要的指导作用。目前业界开发出了许多摩阻预测分析模型,并开展了相关理论研究及案例分析,常用的分析方法有软杆模型、刚杆模型和有限元法。后续学者使用各种理论方法在这3种方法的基础上建立了考虑套管多种受力情况下的摩阻分析模型,但是目前还没有相关研究针对现有模型算法进行汇总及优缺点分析,无法在具体应用时进行模型优选。因此,本文根据基础理论的不同,对目前下套管摩阻模型进行了归类分析,并探讨了下套管摩阻研究与预测存在的技术“瓶颈”与下步发展方向,以期为后续固井三维下套管摩阻分析深度融合发展提供指导和帮助。

The prediction of the hook load during casing insertion is one of the key factors for success.Due to its special wellbore trajectory,the frictional resistance during casing insertion in horizontal wells is higher than that in conventional wells.Therefore,accurately predicting the frictional resistance of casing insertion plays an important guiding role in the design and construction of horizontal well cementing.At present,many friction prediction analysis models have been developed in the industry,and relevant theoretical research and case analysis have been carried out.The commonly used analysis methods include Soft⁃String Model,Stiff⁃String Model and finite element method.Subsequent scholars used various theoretical methods to consider the friction analysis model of casing under various stress conditions on the basis of the three methods,but there is currently no relevant research that summarizes and analyzes the advantages and disadvantages of existing model algorithms,making it impossible to conduct model optimization in specific applications.Therefore,according to different basic theories,this paper classifieds and analyzes the current casing friction models,and discusses the existing technical bottlenecks in casing friction research and prediction as well as the next development direction,in order to provide guidance and help for the in⁃depth integration development of casing friction analysis in the future.