管线腐蚀的切向投影等效面积因子描述方法

Equivalent Area Factor of Tangential Projection Method for Description of Pipeline Corrosion

以油井采出液管线、注水管线以及外输油管线腐蚀为研究对象,统计分析近百例管线腐蚀深度、长度、宽度以及腐蚀形态与腐蚀切向投影面积的关系。依据腐蚀深度、长度、宽度以及腐蚀形态特点,提出了四种腐蚀形貌类型划分方法,以及各类腐蚀切向投影面积因子的取值范围及计算方法,并结合腐蚀深度临界值3.5mm、腐蚀长度临界值40mm以及四种腐蚀形貌类型特点,给出了一种更精确的新等效面积因子的取值方法;将新等效面积因子应用于ASME B31G-1991和ASME B31G-2009的计算方法中,其结果与试验数据的残差平方和以及误差分布稳定性明显优于固定取值的面积因子。提出的管线腐蚀切向投影新等效面积因子的适应性和准确性优于ASME B31G-1991和ASME B31G-2009方法的规定值。

Taking the corrosion of production fluid pipelines,water injection pipelines and external oil pipelines in oil well as research object,the relationships between corrosion depth,length,width,corrosion morphology and corrosion tangential projection area of nearly 100 pipelines were statistically analyzed.According to the characteristics of corrosion depth,length,width and corrosion morphology,four methods for the classification of corrosion morphology as well as the range of values and calculation methods of various corrosion tangential projection area factors were proposed.Combined with the critical value of 3.5 mm of corrosion depth,40 mm of corrosion length and four types of corrosion morphology,a new and more accurate method for the value of equivalent area factor was given.The results calculated by ASMEB 31G-1991 and ASME B31G-2009 using the new equivalent area factor were superior to those using fixed area factor in terms of the sum of the residual square and the error distribution stability.It was shown that the adaptability and accuracy of the newly proposed pipeline corrosion tangential projection equivalent area factor were better than the specified values of ASME B31G-1991 and ASME B31G-2009.