硬电缆下入过程中张力数学模型的建立及分析

根据目前硬电缆在套管井大斜度段固井质量测井中的应用特点,分析了测井过程中各种受力状态,依据力学平衡原理,建立了硬电缆测井过程中缆头张力的理论数学模型,提出了下入过程中缆头张力的计算方法。在此基础上,通过VBA的编程实例,模拟计算了硬电缆下入过程中缆头张力变化,研究了电缆下放速度,硬电缆的长度、尺寸结构等对缆头张力和下入深度的影响。结果表明,井身结构的参数是影响硬电缆缆头张力分布、下入深度的决定性因素,增加硬电缆的长度及减少硬电缆的外径对下入深度的影响作用不明显。

Analysis and Establishment on Hard Cable Tension Mathematical Model of the Logging Process

According to the application characteristics of current hard cable in cementing quality logging in cased wells, a variety of stress state in the logging is analyzed. Based on the principle of mechanical balance, a mathematical model of cable head tension during hard cable logging is established,and the calculation method of cable head tension is put forward.On this basis, the changes of cable head tension are calculated simulatelythrough the VBA programming examples.The influence of cable logging speed, hard cable length, and size structure on the cable head tension and depth are researched. The results show that the parameters of the well body structure is the decisive factor determining the distribution of the cable head tension and the depth of the cable, and the effect of increasing hard cable length and reducing hard cable outer diameter of cable on logging depth is not obvious.