Rock damage mechanisms of hydrocarbon formations re-purposed for geothermal utilization

加拿大是世界上最大的天然气生产国之一。全球变暖和气候变化要求天然气部门和社会从化石燃料转向清洁和可再生能源。一个可行的选择是重新调整油井和气井的用途，以生产可持续的地热能。然而，高流体流速、变化的流体pH和矿化度以及高的闭合应力对地层岩石造成复杂的化学和力学恶化效应，阻碍了对地热利用至关重要的储集层的长期导流能力。拟议的研究项目将使加拿大能够在一个全球重要主题上与一位世界知名的专家合作。该项目的具体目标是(1)研究不同pH值和矿化度的地热流体对不列颠哥伦比亚省东北部克拉克湖附近气藏中遇到的岩层的地球化学影响；(2)调查由于矿物和孔隙结构变化导致的地层岩石强度和渗透率的变化。研究成果将加深我们对地热利用中烃类岩石变质机理的认识，并提供流体pH和盐度的技术建议，以减轻地热作业期间对地层的损害。这为在不列颠哥伦比亚省东北部钻探的20,000多口井和全球数百万口井提供了一个变革性的机会，最终加强了加拿大在发展可持续地热能源方面的作用，并减少了加拿大对化石燃料的依赖。

Canada is one of the largest natural gas producers in the world. Global warming and climate change require the natural gas sector and society to shift from fossil fuels to clean and renewable energy. One viable option is to re-purpose oil and gas wells to produce sustainable geothermal energy. However, high fluid flow rate, varying fluid pH and salinity, and high closure stress present complex chemical and mechanical deteriorating effects on formation rocks, which hinder the long-term conductivity of reservoirs vital to geothermal utilization. The proposed research project will enable collaboration with a world-renowned expert on a globally important subject that can benefit Canada. The specific objectives of the project are to (1) examine the geochemical effect imposed by geothermal fluids with various pH and salinity on rock formations encountered in gas reservoirs near Clarke Lake in northeastern BC, and (2) investigate the changes in the strength and permeability of formation rock due to mineral and pore structure alteration.The research outcomes will improve our understanding of the deterioration mechanisms of hydrocarbon rock formations in geothermal utilization and provide technical recommendations on fluid pH and salinity to mitigate the formation damage during geothermal operation. This provides a step-change opportunity for over 20,000 wells drilled in northeastern BC and millions of wells globally, ultimately enhancing Canada's role in developing sustainable geothermal energy and reducing Canada's reliance on fossil fuel.