套管阴极保护的一种新计算方法及其应用

胜利油田调查表明，腐蚀导致大量油井套管损坏，于 是在一些油井上采用了阴极保护来防止套管腐蚀，但是面临着如何原位地评价井下阴极保护 水平的问题.用美国腐蚀工程师协会标准中的Schremp等人的方法对胜利油田南8-82井进行 计算的结果大部分偏离实测结果10%以上，最大误差接近20%.在本工作中，我们将已建立的 一种原位计算油井套管井下阴极保护电位分布的新方法应用到南8-82井上，所得计算结果与 实测结果的误差均小于6%，从而证实了这种方法的可行性.

APPLICATION OF A NEW CALCULATION METHOD FOR WELL CASING CATHODIC PROTECTION

An investigation showed corrosion caused a lot of casing failures in Shengli Oilfield,so cathodic protection was applied to some oil wells to prevent external casings from corrosion.How to evaluate the downhole cathodic protection levels with no interruption of production was important.When the Schremp's method corresponding to the standard NACE RP0186-94 was used to calculate the casing cathodic protection potentials of Well S8-82 in Shengli Oilfield,the most calculated results were different from the measured ones by more than 10%,the maximum difference was near 20%.In this paper,a new calculation method was proposed and its application on Well S8-82 was reported,all the differences between the calculated and measured cathodic protection potentials were less than 6%,the results confirmed the practicability of the new calculation method.