Ecophysiology of Thermophilic Clostridia in Tight Rock Unconventional Oil Reservoirs

点击翻译按钮获取中文摘要

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.