测井仪外壳体强度蒙特卡罗模拟分析

Shell Intensity Analysis of Logging Tool Using Monte Carlo Simulation

随着钻井井眼直径不断减小和测井深度的不断增加,测井仪器承受的外部压强不断增大,对测井仪外壳体强度要求越来越高。以四探头高精度自然伽马测井仪外壳体设计为例,首先对外壳体初步设计,然后将设计参数诸如结构几何尺寸(长度、内径、外径)、设计压力、屈服强度、应力和外壳体材料的弹性模量、泊松比等作为输入参数,采用蒙特卡罗方法,对外壳体强度进行模拟分析,在置信度为95%时,外壳体的可靠度为100%,则外壳体的初步设计参数满足设计要求。为测井仪外壳体强度的设计提供了新的思路,具有一定的工程应用价值。

With the borehole diameter of drilling well and the increasing of logging depth,the external pressure of the well logging instrument is increasing,and the strength of the shell of the well logging tool is higher and higher.In this paper,the design of the shell of the four probe high precision natural gamma ray logging tool is an example：Firstly,the initial design of the outer shell is made,and then the design parameters：structural geometrical dimensions（length,inner diameter,outer diameter）,design pressure,yield strength,stress and shell material elastic modulus and Poisson＇s ratio are taken as input parameters.By using Monte Carlo method,the strength of external shell is simulated and analyzed.The reliability of the shell is 100% when the confidence is 95%.The preliminary design parameters of the outer shell can meet the design requirements,provides a new idea for the design of logging casing strength,it has certain engineering application value.