L2M NSERC - Fibre Optic Technology Innovation for Subsurface Fracture Characterization

L2M NSERC - 用于地下断裂表征的光纤技术创新

• 批准号: 580692-2023
• 负责人: Eaton, DavidWS
• 金额: $ 1.46万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Idea to Innovation
• 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=755089
• 关键词: L2M; NSERC; Fibre; Optic; Technology

During resource exploration, monitoring induced microseismicity and imaging the subsurface has typically been undertaken using geophones. Recently, fibre optic technology (e.g., Distributed Acoustic Sensing (DAS), Distributed Temperature Sensing (DTS)) has shown advantages over geophones, such as the ability to monitor the entire fibre (enhanced spatial resolution) and over broad frequencies. DAS/DTS therefore provides an effective solution for subsurface imaging, detecting microseismicity and slow slip using the same instrumentation. In most instances, a fibre optic cable is installed into a single horizontal well adjacent to others at a multi-well pad. A single fibre can detect microseismic events but, unlike multicomponent geophones, it cannot unambiguously determine source locations since it records only one direction of ground motion. Determination of event locations is essential for fracture mapping and characterization as well as determining operational success and for risk management. We have created novel methods that use recorded reflected waves on fibre optic cables to better determine locations of microseismic events, and to characterize fracture aperture and proppant distribution. Using the standard practice of picking the direct wave arrivals, locating microseismic events with a single fibre optic cable lacks depth resolution. Like scanning a bar code, our approach decodes event depth based on the detected pattern of reflections from horizontal layer boundaries, which are typically discarded. We also use subtle amplitude variations of reflections from vertical hydraulic fractures to determine critical characteristics such as fracture aperture and proppant, which are otherwise unknown. Integrating these calculations into a workflow focusing on the identification and location of microseismicity would be transformative, enabling industry to gain a better understanding of the extent and characteristics of fractures in the subsurface. We aim to enhance our technology to account for evolving demands, allowing integration of our technology by many different clients.

在资源勘探期间，通常使用地震检波器监测诱发的微震活动和对地下成像。最近，光纤技术（例如，分布式声学传感（DAS）、分布式温度传感（DAS）已经显示出优于地震检波器的优点，例如能够监测整个光纤（增强的空间分辨率）和宽频率。因此，DAS/DAS提供了一个有效的解决方案，地下成像，检测微震和慢滑使用相同的仪器。在大多数情况下，光纤电缆被安装到与多井场处的其它水平井相邻的单个水平井中。一个单一的纤维可以检测到微震事件，但不像多分量地震检波器，它不能明确地确定源位置，因为它只记录一个方向的地面运动。事件位置的确定对于裂缝测绘和表征以及确定操作成功和风险管理至关重要。我们已经创造了新的方法，使用记录的反射波的光纤电缆，以更好地确定位置的微震事件，并表征裂缝孔径和支撑剂分布。使用拾取直达波到达的标准实践，用单个光纤电缆定位微震事件缺乏深度分辨率。像扫描条形码一样，我们的方法基于检测到的来自水平层边界的反射图案来解码事件深度，这些反射图案通常被丢弃。我们还使用微妙的振幅变化的反射垂直水力裂缝，以确定关键的特性，如裂缝孔径和支撑剂，这是未知的。将这些计算整合到专注于识别和定位微震活动的工作流程中将是变革性的，使行业能够更好地了解地下裂缝的范围和特征。我们的目标是提高我们的技术，以满足不断变化的需求，使我们的技术集成了许多不同的客户。