水平井中测井管柱的力分析机理

水平井测井管柱细、重量轻,能否靠管柱自重把测井仪器下放到井底是一个十分重要的技术问题。为此,本文以水平井测井管柱为研究对象,考虑管柱与井壁的初始间隙和随机接触摩擦阻力,建立了测井管柱力分析模型,采用“多向接触摩擦间隙元”理论对该模型进行了接触非线性力学分析。经大庆油田MP1井测井管柱五种工况下的力分析表明,测井管柱井口最小悬重值为15.83kN,仍处于拉伸状态,测井仪器不需注入器,靠管柱自重完全可以下放到井底。这一结论已被工程应用和验证。由此,该研究为分析水平井测井管柱的受力机理提供了一种新的理论依据,为工程中预测测井仪器是否靠管柱自重或注入器下放到井底提供了一种技术手段。

AN MECHANICS ANALYSIS OF THE PRODUCTION LOGGING STRING IN A HORIZONTAL WELL

It is an extremly important problem in horizontal well is that if the logging instrument can resch bottom hole by the string weight, thelogging string is very thin and its weight is very light.Therefore, a whole string mechanical model is established in the paper, and the multi-directional contact gap element theory is applied to analyzed the contact non-linear prodledm.In the model, the whole logging string is studied and the initial gap and the random contact frictional resistance between the logging string and the hole wall are considered. In Daqing oil field, the logging string forec of MPI well is analyzed by the theory in five working conditions, which shown that the minimum hook load is 15.83kN and the well head string is in tensile state so that the logging instrument can reach bottom hole by the string weight and no injector is needed.The analysis result is applied successfuly in engineer, hence, a new calculation method for the force analysis of logging string is presented and provides a technique for predicting the logging instrument to reach bottom hole whether by the string weight or an injector.