Ecophysiology of Thermophilic Clostridia in Tight Rock Unconventional Oil Reservoirs

世界上相当大比例的石油储量被困在孔隙率极低的紧密结合的富含有机物的页岩中，通常被称为致密岩石非常规（TRU）储层。加拿大的大部分TRU地层位于阿尔伯塔和不列颠哥伦比亚省的沉积盆地内，并且以高温为特征，例如高于60摄氏度。通过水平钻井结合水力压裂实现从TRU储层中有利可图的采油，水力压裂是一种新兴技术，依赖于向深层页岩储备中注入大量水。尽管在生产策略方面与传统油田有很大不同，但TRU生产设施遇到了类似的问题，例如有毒硫化氢的不必要的生产以及由不受控制的微生物活动引起的上部设施的腐蚀。在热储层中，微生物群落及其活动的影响仍然知之甚少。该项目将与加拿大雪佛龙公司合作，研究适应破裂的TRU地层内极端温度、盐度和压力的嗜热嗜盐孢子形成梭菌。主要目标是根据对深层TRU储层中这些细菌的生存及其对出油管和上部结构设施中温度降低的反应的了解，为雪佛龙提出微生物控制建议。该项目还将调查回流和采出水的再循环如何影响微生物活性和有害代谢物的相关生产。所产生的信息将有助于更好地预测雪佛龙加拿大公司的TRU运营中的潜在有害影响，从而提出具体的垃圾处理和回收建议，并为这些重要资产提供明智的风险管理和决策。在预期从这些储层中增加产量的背景下，该项目为加拿大提供了巨大的经济，社会和环境效益，保护这一新兴行业免受石油和天然气行业中众所周知的微生物陷阱和危害。

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.