%0 Journal Article
%T Predictive Modelling of Wellhead Corrosion due to Operating Conditions: A Field Data Approach
%A Chinedu I. Ossai
%J ISRN Corrosion
%D 2012
%R 10.5402/2012/237025
%X The flow of crude oil, water, and gas from the reservoirs through the wellheads results in its deterioration. This deterioration which is due to the impact of turbulence, corrosion, and erosion significantly reduces the integrity of the wellheads. Effectively managing the wellheads, therefore, requires the knowledge of the extent to which these factors contribute to its degradation. In this paper, the contribution of some operating parameters (temperature, CO2 partial pressure, flow rate, and pH) on the corrosion rate of oil and gas wellheads was studied. Field data from onshore oil and gas fields were analysed with multiple linear regression model to determine the dependency of the corrosion rate on the operating parameters. ANOVA, value test, and multiple regression coefficients were used in the statistical analysis of the results, while in previous experimental results, de Waard-Milliams models and de Waard-Lotz model were used to validate the modelled wellhead corrosion rates. The study shows that the operating parameters contribute to about 26% of the wellhead corrosion rate. The predicted corrosion models also showed a good agreement with the field data and the de Waard-Lotz models but mixed results with the experimental results and the de Waard-Milliams models. 1. Introduction Corrosion of materials is a major challenge to maintaining the integrity of equipment in the industry. Mobile and static mechanical equipment like pipelines, vessels, tanks, compressors, turbines, and so forth have been periodically subjected to degradation and failure due to corrosion. According to reports [1], the cost of corrosion in the US will hit 6.2% of GDP in 2012, making it the most expensive single venture in the economy. The impact of corrosion in the oil and gas industry significantly contributes to the nonproductive time (NPT) of 20¨C30% lost from exploration to production [2]. Corrosion of pipeline accounts for about 35% of failures associated with pipeline leakage and bursting in Canada [3], while 50% of the loss of containment hazard in Europe between 1980 and 2006 was a result of the ageing plant mechanism [4] triggered by corrosion-related fatigue cracking and erosion. Corrosion also ranks second to the highest most frequent initiating factor leading to loss of containment in UK [4, 5]. While external corrosion, stress corrosion cracking, and microbiologically influenced corrosion have significantly resulted in pipeline failures, failure attributable to sour and sweet corrosion which results from activities of CO2 and H2S has contributed to over 50% of all
%U http://www.hindawi.com/journals/isrn.corrosion/2012/237025/