Improving characterization and modelling of the rock-proppant interaction in hydraulic fractures for deep-earth geo-resource extraction

改进水力压裂中岩石-支撑剂相互作用的表征和建模，以进行深地地质资源开采

• 批准号: RGPIN-2021-04215
• 负责人: Zheng, Wenbo
• 金额: $ 1.89万
• 依托单位: University of Northern British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=764699
• 关键词: Improving; characterization; modelling; rock; proppant

The Canada Energy Regulator predicts Canadian natural gas production to grow to 606 million cubic metres per day over the next two decades. The production will be mainly from the natural gas reserves trapped in tight and low-permeability rock formations 2-3 km below surface. Massive amounts of proppants, mostly frac sand, are placed into fractures created by hydraulic fracturing to increase the fracture conductivity and enhance the long-term hydrocarbon recovery from tight formations. Experiences from well stimulation operations have already demonstrated that the rock-proppant mechanical interaction under high compressive stress significantly influences fracture conductivity and, thus, gas productivity. However, there is a lack of comprehensive and quantitative characterization of how fracture conductivity evolves during well production life, due to the limitations in existing laboratory tests and predictive models where complex interaction between proppants and rock is over-simplified. Many important impact factors have not yet been fully captured in the complex rock-proppant systems, such as rock fracture topography, proppant size, and proppant creep indentation into rock faces. These shortcomings have significantly impaired our ability to correctly predict proppant behaviours in rock fractures, resulting in the inappropriate selection of proppants for hydraulic fracturing. Recent progress in my research activities has identified the need to rigorously model proppant crushing between fractures for satisfactory prediction of fracture conductivity. For this, we have developed a numerical breakage model to successfully simulate grain breakage at high compressive stress. The research program proposed for this Discovery Grant will build on our existing successes and further advance the characterization and modelling of the rock-proppant interaction in fractures for resource extraction. This goal will be achieved through training HQP in interlinked research tasks with advanced laboratory geo-materials characterization, geomechanical testing, and numerical and analytical modelling. The research outcomes will deliver and promote new knowledge and tools for improving the extraction efficiency that is crucial to the sustainable development of the Canadian natural gas industry. Characterization techniques of proppants and rock and predictive models of hydraulic-mechanical behaviours will be developed to better apply proppants in hydraulic fracturing for deep earth resource recovery while minimizing environmental impacts associated with proppant mining and transportation. Close collaboration with existing industry and academic partners will ensure rapid dissemination of research outcomes and facilitate optimization opportunities in natural gas development projects. HQP will be equipped with essential skills that are highly desirable in the Canadian natural resource sector.

加拿大能源监管机构预测，在接下来的二十年中，加拿大天然气的产量每天增长到每天6.06亿立方米。生产主要来自被困在表面下2-3公里的紧密和低渗透岩层中的天然气储量。将大量的支撑剂（主要是冰砂）放在液压压裂产生的裂缝中，以增加断裂电导率并增强从紧密地层中的长期烃回收。井刺激操作的经历已经表明，高压应力下的岩石促进机械相互作用会显着影响断裂电导率，从而影响气体生产力。但是，由于现有实验室测试的局限性和预测模型的局限性，在井生产寿命中，缺乏全面和定量的表征，这些模型的局限性过多，而Proppant和Rock之间的复杂相互作用被过度简化。在复杂的岩石螺旋桨系统中，尚未完全捕获许多重要的影响因素，例如岩石裂缝地形，支撑剂的大小和岩石面的支撑剂蠕变凹痕。这些缺点极大地损害了我们正确预测岩石裂缝中的支撑剂行为的能力，从而导致选择了用于液压压裂的支撑剂的选择。我的研究活动的最新进展已经确定需要严格模拟裂缝之间的支撑剂粉碎，以满足裂缝电导率的预测。为此，我们开发了一个数值破裂模型，以成功模拟高压应力下的晶粒破裂。为这项发现赠款提出的研究计划将基于我们现有的成功，并进一步推动裂缝中岩石偏见相互作用的表征和建模，以进行资源提取。将通过培训HQP在与先进的实验室地理材料表征，地质力学测试以及数值和分析建模的相互联系的研究任务中训练HQP实现。研究成果将为提高加拿大天然气行业至关重要的提取效率提供新的知识和工具，以提高提取效率。将开发出支撑剂和岩石的表征技术以及水力机械行为的预测模型，以更好地将支撑剂应用于液压压裂中，以进行深层的土壤资源恢复，同时最大程度地降低了与支撑剂采矿和运输相关的环境影响。与现有行业和学术合作伙伴的密切合作将确保快速传播研究成果，并促进天然气开发项目中的优化机会。 HQP将配备加拿大自然资源部门非常需要的基本技能。