The Bowland Shale Formation is one of the most promising targets for unconventional exploration in the United Kingdom, with estimated resources large enough to supply the country's entire natural gas consumption for 50 years. However, development of the Bowland Shale has stalled due to concerns over hydraulic-fracturing-induced seismicity. Only three wells have been drilled and hydraulic-fractured to date in the Bowland Shale, and all three have produced levels of seismicity of sufficient magnitude to be felt at the surface. Susceptibility to induced seismicity will be determined by the presence of critically stressed faults. However, such faults can go undetected in conventional interpretation of 2D or 3D seismic surveys if they are shorter than the resolution retrievable from a seismic survey, or if they have low (and in some cases even zero) vertical displacement. In such cases, the faults that cause induced seismicity may only be visible via microseismic observations once they are reactivated. To better identify fault planes from 3D seismic images, and their reactivation potential due to hydraulic fracturing, a high-resolution fault-detection attribute was tested in a 3D seismic survey that was acquired over the Preston New Road site, where two shale-gas wells were hydraulic-fractured in the Bowland Shale in 2018 and 2019, obtaining fault planes with lengths between 400 and 1500 m. Fault slip potential was then estimated by integrating the obtained faults with the formation's stress and pore pressure conditions (with the Bowland shale also being significantly overpressured), and several critically stressed faults were identified near the previously hydraulic fractured wells. However, the faults that induced the largest seismic events in the Preston New Road site, of c. 200 m in length for seismic events of magnitudes below 3.0 (as imaged with a multicomponent, downhole microseismic monitoring array deployed during the hydraulic-fracturing stimulations), could not be identified in the 3D seismic survey, which only mapped fault planes larger than 400 m in length.

Bowland 页岩组是英国非常规勘探最有希望的目标之一，估计其资源量足以供应该国 50 年的全部天然气消耗量。然而，由于对水力压裂引起的地震活动的担忧，Bowland 页岩的开发已经停滞。迄今为止，在 Bowland 页岩中仅钻探了三口井并进行了水力压裂，并且所有三口井都产生了足以在地表感觉到的地震活动水平。诱发地震的敏感性将取决于临界应力断层的存在。但是，如果此类断层短于地震勘测可检索的分辨率，则在 2D 或 3D 地震勘测的常规解释中可能无法检测到此类断层，或者如果它们的垂直位移很低（在某些情况下甚至为零）。在这种情况下，导致诱发地震的断层可能只有在重新激活后才能通过微震观测才能看到。为了更好地从 3D 地震图像中识别断层及其因水力压裂而重新激活的潜力，在 Preston New Road 现场采集的 3D 地震勘测中测试了高分辨率断层检测属性，其中两口页岩气井2018 年和 2019 年在 Bowland 页岩进行水力压裂，获得长度在 400 和 1500 m 之间的断层。然后通过将获得的断层与地层的应力和孔隙压力条件（Bowland 页岩也显着超压）相结合来估计断层滑动潜力，在先前的水力压裂井附近发现了几个临界应力断层。然而，在普雷斯顿新路现场引发最大地震事件的断层，C。3.0 级以下地震事件的 200 m 长度（使用在水力压裂刺激期间部署的多分量井下微震监测阵列成像）无法在 3D 地震勘测中识别，该勘测仅绘制了大于 400 m 的断层平面长度。