Ecophysiology of Thermophilic Clostridia in Tight Rock Unconventional Oil Reservoirs

世界上相当大一部分石油储量被圈闭在紧密结合的富含有机物质的页岩中，孔隙度极低，通常被称为致密岩非常规(TRU)储层。加拿大的绝大多数TRU地层位于艾伯塔省和不列颠哥伦比亚省的沉积盆地内，具有高温的特点，例如60摄氏度以上。从TRU油层进行有利可图的采油是通过水平钻井和水力压裂相结合实现的，水力压裂是一项新兴技术，依赖于向深层页岩储量注入极大量的水。尽管在生产策略上与传统油田有很大的不同，但TRU生产设施遇到了类似的问题，如有害的有毒硫化氢产生，以及由于微生物活动不受控制而导致上部设施的腐蚀。在高温的TRU水库中，微生物群落及其活动的影响仍然知之甚少。该项目将与雪佛龙加拿大公司合作，研究适应TRU裂缝地层中极端温度、盐度和压力的高温嗜盐芽胞形成梭菌。主要目标是在了解这些细菌在深层TRU储油层中的生存以及它们对输油管和上部设施中温度下降的反应的基础上，为雪佛龙提出微生物控制建议。该项目还将调查回流水和产出水的回收如何影响微生物活动和有害代谢物的相关生产。生成的信息将使我们能够更好地预测雪佛龙加拿大TRU运营中的潜在有害影响，从而为这些重要资产提供针对特定水库的处理和回收建议，以及知情的风险管理和决策。在这样的TRU储集层预期产量增加的背景下，该项目通过保护这一新兴行业免受石油和天然气行业众所周知的微生物陷阱和危害，为加拿大带来了巨大的经济、社会和环境效益。

A considerable proportion of the world's petroleum reserves are trapped within tightly bound organic-rich shale rocks with extremely low porosity, commonly referred to as tight rock unconventional (TRU) reservoirs. A large majority of the TRU formations in Canada are situated within the sedimentary basins of Alberta and British Columbia, and are characterized by high temperatures e.g. above 60 degrees Celsius. Profitable oil recovery from TRU reservoirs is achieved by horizontal drilling combined with hydraulic fracturing, an emerging technology that relies on injection of extremely large volumes of water into the deep shale reserves. Although very different from conventional oil fields in terms of production strategies, TRU production facilities encounter similar problems such as unwanted production of toxic hydrogen sulfide and corrosion of topsides facilities stemming from uncontrolled microbial activity. In hot TRU reservoirs, the impact of microbial communities and their activities remain poorly understood. In collaboration with Chevron Canada, this project will investigate thermohalophilic spore-forming Clostridia adapted to the extreme temperature, salinity and pressure within fractured TRU formations. The primary goal is to advance microbial control recommendations for Chevron based on understanding the survival of these bacteria in deep TRU reservoirs and their response to decreasing temperatures in flowlines and topsides facilities. The project will also investigate how recycling of flowback and produced water impacts microbial activity and associated production of deleterious metabolites. Information generated will enable better prediction of potential deleterious effects in Chevron Canada's TRU operations, leading to reservoir-specific treatment and recycling recommendations, and informed risk management and decision-making for these important assets. In the context of increasing production anticipated from TRU reservoirs such as these, the project offers great economic, social and environmental benefits to Canada by safeguarding this nascent industry from the pitfalls and harms that microorganisms are well known for in the oil and gas sector.