Absrract
It is standard practice to use a coating system as the primary defense in preventing external corrosion on pipelines. Additionally, pipelines installed by Horizontal Directional Drilling (HDD), also require special coatings which have high abrasion resistance to minimize damage during pull through. However, given the aggressive nature of the installation method, some degree of compromised coating is inevitable. It is speculated that corrosion at the coating holidays will be suppressed through application of cathodic protection (CP). Considering the uncertainty of effective CP at HDDs, it is important to be proactive and consider additional measures to prevent any detrimental effects that the HDD drilling fluid may have on the pipeline. Being proactive supports the development of leading practices and reinforces a focus on safe operation and improved safety performance. This paper presents a case study on the evaluation of the effectiveness of environmentally benign and biodegradable enzymes in drilling fluid associated with HDD against Microbiologically Influenced Corrosion (MIC) associated biofilms. Corrosive biofilm formation on pipeline surfaces can have serious impacts on the safety and reliability of energy infrastructure. Once initiated, biofilms are extremely difficult to remove. It is also well known that the application of biocides alone does not completely remove the protective slime layer of biofilms.1 To enhance the effectiveness of biocides, research into using enzymes to target the protective extracellular polymeric substances (EPS) of biofilms has been studied.2 This case study will discuss the methodology to decrease the amount of biocides needed to mitigate corrosive biofilms by increasing its effectiveness, ultimately reducing the threat of corrosion to HDD pipelines from potential MIC.
