Biocorrosion: Predicting and responding to new types of microbially-influenced corrosion in the oil and gas industry

金属腐蚀影响到多个行业，对环境和人类安全构成重大风险，估计在全球造成超过2.5万亿GB的经济损失(约占全球GDP的6%)。微生物影响的腐蚀(MIC)被认为在其中起主要作用，但由于我们对MIC相关过程的有限了解，无法进行准确的估计。在石油和天然气行业，生物腐蚀通常与硫酸盐还原菌(SRB)引起的“酸化”问题有关，SRB在地下储集层和上部设施中产生腐蚀性硫化氢。为了解决酸化问题，油藏工程师已经开始将硝酸盐注入作为一种绿色生物技术，利用这种生物技术，各种硫化物氧化硝酸盐还原细菌(SoNRB)可以催化去除硫化物。然而，这项前景看好的技术受到了威胁，因为有报道称，soNRB可能通过将硫化物不完全氧化成腐蚀性硫中间体来增强局部腐蚀。在某些情况下，soNRB可能具有腐蚀性；soNRB代谢的最终产物因硫化物(即SRB催化的水库酸化)和硝酸盐(即为防止酸化而引入的工程“硝酸盐剂量”)的普遍水平而不同。此外，SoNRB腐蚀将取决于存在的特定菌株的特定生理特征，这些特征因油田而异，但通常包括变形杆菌--中温油田16S rRNA基因组调查中最常见的细菌门。随着廉价、高通量的核酸测序技术的出现，生物学知识的新时代正在到来，这些技术现在可以应用于微生物基因组学。新的高通量测序平台允许在DNA(基因组)和RNA(转录)水平上对微生物群落进行前所未有的水平的询问。工程生物学旨在通过将这些强大的工具应用于生物腐蚀等工业问题来利用这场生物“组学”革命的力量。该项目将把基因组学和转录组学与soNRB新陈代谢的过程测量和通过线性极化电阻进行实时腐蚀监测相结合。通过在试验性油田微观世界中测量所有这些变量，并扩大到泛行业油田筛选，将出现对与氮和硫生物转化相关的腐蚀的预测性理解，将新的诊断基因组分析交到石油工程师手中。石油行业需要硝酸盐注射等绿色技术。这项研究将开发新的方法，通过允许提前评估与硝酸盐相关的生物腐蚀潜力来保护这项前景光明的技术。这将加强硝酸盐注射的持续成功应用，使其基于知情的风险评估。

Corrosion of metals affects multiple industries and poses major risks to the environment and human safety, and is estimated to cause economic losses in excess of £2.5 trillion worldwide (around 6% of global GDP). Microbiologically-influenced corrosion (MIC) is believed to play a major role in this, but precise estimates are prevented by our limited understanding of MIC-related processes.In the oil and gas sector biocorrosion is usually linked to the problem of "souring" caused by sulfate-reducing bacteria (SRB) that produce corrosive hydrogen sulfide in subsurface reservoirs and topsides facilities. To combat souring, reservoir engineers have begun turning to nitrate injection as a green biotechnology whereby sulfide removal can be catalysed by diverse sulfide-oxidising nitrate-reducing bacteria (soNRB). However, this promising technology is threatened by reports that soNRB could enhance localized corrosion through incomplete oxidation of sulfide to corrosive sulfur intermediates. It is likely that soNRB are corrosive under certain circumstances; end products of soNRB metabolism vary depending prevailing levels of sulfide (i.e., from the SRB-catalyzed reservoir souring) and nitrate (i.e., the engineering "nitrate dose" introduced to combat souring). Furthermore soNRB corrosion will depend on the specific physiological features of the particular strains present, which vary from field to field, but usually include members of the Epsilonproteobacteria - the most frequently detected bacterial phylum in 16S rRNA genomic surveys of medium temperature oil fields. A new era of biological knowledge is dawning with the advent of inexpensive, high throughput nucleic acid sequencing technologies that can now be applied to microbial genomics. New high throughput sequencing platforms are allowing unprecedented levels of interrogation of microbial communities at the DNA (genomic) and RNA (transcriptomic) levels. Engineering biology aims to harness the power of this biological "-omics" revolution by bringing these powerful tools to bear on industrial problems like biocorrosion.This project will combine genomics and transcriptomics with process measurements of soNRB metabolism and real time corrosion monitoring via linear polarization resistance. By measuring all of these variables in experimental oil field microcosms, and scaling-up to pan-industry oil field screening, a predictive understanding of corrosion linked to nitrogen and sulfur biotransformations will emerge, putting new diagnostic genomics assays in the hands of petroleum engineers.The oil industry needs green technologies like nitrate injection. This research will develop new approaches that will safeguard this promising technology by allowing nitrate-associated biocorrosion potential to be assessed in advance. This will enhance nitrate injection's ongoing successful application to be based on informed risk assessments.