Understanding the coupled transport of water and ions in gas shales for interpreting hydraulic fracture flowback data

了解含气页岩中水和离子的耦合传输以解释水力压裂返排数据

• 批准号: 468101-2014
• 负责人: Dehghanpour, Hassan
• 金额: $ 3万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=618602
• 关键词: Understanding; coupled; transport; water; ions

Oil and gas production from tight hydrocarbon resources by drilling and completion of multilateral/multifractured horizontal wells is becoming a common practice in the North America. However, efficient, responsible, and sustainable development of such resources requires careful evaluation of massive hydraulic fracturing operations involved. The main concerns include 1) inefficient recovery of fracturing water, 2) high concentration of various salts in the produced water, and 3) lack of reliable models for characterizing the induced fracture network using the pressure, rate and concentration data measured during flowback operations.This research hypothesizes that a large fraction of non recovered water is imbibed into the shale matrix during the shut-in period. To test this hypothesis, extensive flow experiments will be conducted on shale samples selected from cores drilled into different shale members of the Horn River Basin, located in northeastern British Colombia. It is estimated that up to 500 TCF of natural gas is stored in this basin, making it the third largest North American natural gas accumulation. This experimental study is aimed at understanding the fundamental mechanisms controlling the imbibition of fracture water into the shale matrix and diffusion of ions from shale into fracture water. Furthermore, the experimental data will be modeled to obtain the parameters required for modelling field scale processes including 1) spontaneous water leak off and salt concentration build up in fractures during the well shut in period, and 2) transport of water and salt during flowback operations.The proposed research, that will be conducted by two PhD and two MSc students, will help the industry to understand the complex interaction between water and shale for evaluating fracturing operations and optimizing future development plans.

在北美，通过多口/多缝水平井钻完井从致密烃资源中开采油气已成为一种普遍做法。然而，高效、负责任和可持续地开发这些资源需要对所涉及的大规模水力压裂作业进行仔细的评估。主要问题包括：1)压裂水回收效率低；2)采出水中各种盐的浓度较高；3)利用反排作业中测量的压力、速率和浓度数据，缺乏可靠的模型来表征诱导裂缝网络。本研究假设，在关井期间，有很大一部分未回收的水被吸收到页岩基质中。为了验证这一假设，将对页岩样品进行广泛的流动实验，这些样品取自位于不列颠哥伦比亚东北部合恩河盆地不同页岩区的岩心。据估计，该盆地的天然气储量高达500万亿立方英尺，使其成为北美第三大天然气聚集地。本实验旨在了解控制裂缝水向页岩基质的渗吸和页岩离子向裂缝水扩散的基本机制。此外，将对实验数据进行建模，以获得模拟现场规模过程所需的参数，包括1)关井期间裂缝中自发的水泄漏和盐浓度的积累，以及2)反排作业期间水和盐的运移。这项研究将由两名博士和两名硕士研究生进行，将帮助业界了解水和页岩之间复杂的相互作用，以评估压裂作业和优化未来的开发计划。