APPLICATION OF A NEW CALCULATION METHOD FOR WELL CASING CATHODIC PROTECTION
套管阴极保护的一种新计算方法及其应用

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.