Brimstone and Treacle: Understanding Oil-Driven Microbial Souring In Petroleum Reservoirs

硫磺和糖浆：了解石油储层中石油驱动的微生物酸化

• 批准号: 2127659
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2127659
• 关键词: Brimstone; Treacle; Understanding; Oil; Driven

Reservoir souring is a widespread problem within the petroleum industry. It is characterised by an increase in sulfide concentrations within a reservoir, and it's produced fluids, over time. This reduces crude oil quality and consequently its market value, drives corrosion of infrastructure, and presents safety concerns for workers. Accommodating for these issues significantly inflates the cost of drilling and refining operations. Sulfate reducing microorganisms (SRM) are thought to be responsible for the majority of souring. SRM "breathe" sulfate, using it during respiration as an acceptor of electrons obtained from food (electron donors) and reducing it to sulfide. As souring is intrinsically linked to the activity of SRM, it is heavily influenced by conditions within an oil reservoir, such as temperature, salinity, pH, availability of nutrients and electron donors/acceptors. Due to the myriad of problems souring poses to the petroleum industry, there has been a concerted effort to understand its underlying mechanisms and produce accurate predictive models. This project will focus on the role of crude oil composition in determining the likelihood/extent of souring observed within a petroleum reservoir. Crude oil is the main provider of electron donors for SRM, and some oils contain hydrocarbon fractions that have displayed toxicity to microbes. As crude oils show massive variations in their composition, they may also display significant variation in their propensity to support souring. The key aim of this project is to describe the relationship between oil composition and souring, in the hopes of improving the ability to predict how souring may develop within an oil reservoir. This will be done by sourcing a wide array of crude oil samples, and analysing them using cutting edge chromatography techniques to gain a detailed picture of their composition. Using laboratory microcosms as analogues to oil reservoirs, the souring potentials of these oils will be assessed. Using these highly controlled laboratory systems will allow for a definitive assessment of composition/souring relationships, unachievable simply by in situ observations of oil reservoirs. In addition to testing the souring potential of each oil, detailed analysis of the microbial communities they support will be undertaken using metagenomics. This will hopefully allow for a deeper understanding of the interactions between oil composition and souring, as a detailed view of the microbial communities supported by an oil can be established. Initial areas of investigation will involve establishing general trends between the differences in souring potential of non-biodegraded (light) oils compared to more biodegraded (heavier) oils. Less biodegraded oils are more abundant in smaller hydrocarbon fractions that are more easily used as a source of electron donors by reservoir microbes, however they also contain the higher concentrations of toxic hydrocarbon fractions. Once a general trend is established there will be further probing into the nuances of this relationship, as in the real world two oil reservoirs containing oils with similar levels of bio-degradation can display vastly different levels of souring. Subject to this research, further study into individual oil components, or groups of oils components and their culpability in supporting/inhibiting souring may be undertaken. Microcosms present a useful tool to investigate souring under highly controlled conditions and will be used extensively during this project, however there are certainly criticisms as to how well they truly represent a complex reservoir environment. Later stages of the project will therefore involve the use of advection based systems to study souring, in the form of packed bioreactors which are more representative of the turbulent conditions within an oil reservoir during drilling activities.

油藏酸化是石油工业中普遍存在的问题。其特点是储层内硫化物浓度随着时间的推移而增加，并产生流体。这降低了原油质量，从而降低了其市场价值，加剧了基础设施的腐蚀，并给工人带来了安全隐患。解决这些问题会大大增加钻井和炼油作业的成本。硫酸盐还原微生物（SRM）被认为是造成大部分酸味的原因。 SRM“呼吸”硫酸盐，在呼吸过程中将其用作从食物（电子供体）获得的电子的受体，并将其还原为硫化物。由于酸化与 SRM 的活性有内在联系，因此它在很大程度上受到油藏内条件的影响，例如温度、盐度、pH、营养物的可用性和电子供体/受体。由于酸化给石油工业带来了无数问题，人们齐心协力了解其根本机制并建立准确的预测模型。该项目将重点研究原油成分在确定石油储层内观察到的酸化可能性/程度方面的作用。原油是 SRM 电子供体的主要提供者，一些油中含有对微生物表现出毒性的碳氢化合物馏分。由于原油的成分存在巨大差异，因此它们支持酸化的倾向也可能存在显着差异。该项目的主要目的是描述石油成分与酸化之间的关系，希望提高预测油藏内酸化如何发展的能力。这将通过采购各种原油样品并使用尖端色谱技术对其进行分析来获得其成分的详细图片来完成。使用实验室微观世界作为油藏的类似物，将评估这些油的酸化潜力。使用这些高度控制的实验室系统将能够对成分/酸化关系进行明确的评估，这是仅通过油藏现场观察无法实现的。除了测试每种油的酸化潜力外，还将使用宏基因组学对其支持的微生物群落进行详细分析。这有望使人们更深入地了解石油成分和酸化之间的相互作用，因为可以建立石油支持的微生物群落的详细视图。最初的研究领域将涉及确定非生物降解（轻质）油与更多生物降解（较重）油的酸化潜力差异之间的总体趋势。生物降解程度较低的油在较小的烃馏分中更丰富，更容易被储层微生物用作电子供体来源，但它们也含有较高浓度的有毒烃馏分。一旦确定了总体趋势，就会进一步探讨这种关系的细微差别，因为在现实世界中，两个含有生物降解水平相似的油的油藏可能会表现出截然不同的酸化程度。根据这项研究，可以对单个油成分或油成分组及其在支持/抑制酸化中的作用进行进一步研究。微观世界提供了一种在高度控制的条件下研究酸化的有用工具，并将在该项目中广泛使用，但对于它们如何真正代表复杂的油藏环境，肯定存在批评。因此，该项目的后期阶段将涉及使用基于平流的系统来研究酸化，其形式是填充生物反应器，它更能代表钻井活动期间油藏内的湍流条件。