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，估计在全球范围内造成的经济损失超过2.5万亿英镑（约占全球GDP的6%）。微生物影响腐蚀（MIC）被认为在这方面起着重要作用，但由于我们对MIC相关过程的了解有限，无法进行精确的估计。在油气领域，生物腐蚀通常与硫酸盐还原细菌（SRB）在地下储层和上层设施中产生腐蚀性硫化氢引起的“酸化”问题有关。为了对抗酸化，油藏工程师开始将硝酸盐注入作为一种绿色生物技术，通过多种硫化物氧化硝酸盐还原细菌（soNRB）催化硫化物的去除。然而，有报道称soNRB可以通过硫化物不完全氧化成腐蚀性硫中间体来增强局部腐蚀，这一有前途的技术受到了威胁。在某些情况下，soNRB可能具有腐蚀性；soNRB代谢的最终产物根据硫化物（即来自srb催化的储层酸化）和硝酸盐（即用于对抗酸化的工程“硝酸盐剂量”）的普遍水平而变化。此外，soNRB腐蚀将取决于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Epsilonproteobacteria的成员-这是中温油田16S rRNA基因组调查中最常检测到的细菌门。随着廉价、高通量核酸测序技术的出现，生物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（转录组）水平上对微生物群落进行前所未有的调查。工程生物学的目标是利用这种生物“组学”革命的力量，将这些强大的工具用于解决生物腐蚀等工业问题。该项目将结合基因组学和转录组学，soNRB代谢的过程测量和通过线性极化电阻进行的实时腐蚀监测。通过测量实验油田微观环境中的所有这些变量，并将其扩展到泛行业油田筛选，对与氮和硫生物转化相关的腐蚀的预测性理解将会出现，从而将新的诊断基因组分析方法交到石油工程师手中。石油工业需要像注入硝酸盐这样的绿色技术。这项研究将开发新的方法，通过允许提前评估硝酸盐相关的生物腐蚀潜力，来保护这一有前途的技术。这将在知情的风险评估基础上加强硝酸盐注射的成功应用。

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.