Questioning the Existence of Hydraulic Fracturing-Induced LPLD Events in a Barnett Shale, Texas, Microseismic Dataset
Questioning the Existence of Hydraulic Fracturing-Induced LPLD Events in a Barnett Shale, Texas, Microseismic Dataset
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质疑德克萨斯州 Barnett 页岩微震数据集中水力压裂诱发的 LPLD 事件的存在
DOI：
10.3997/2214-4609.201600004
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Dana Jurick
中科院分区：
文献类型：
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作者：
M. Zecevic;G. Daniel;Dana Jurick
最近的研究已经识别和表征了一种类型的地震事件，称为LPLD事件，其已经在水力压裂操作期间获取的微震数据集中检测到（例如，Das和Zoback，2011; 2013 a; 2013 b; Mitchell等人，2013; Kwietniak，2015）。这些事件被解释为沿沿着预先存在的裂缝缓慢滑动的表现，这些裂缝被认为与当前的主应力方向不对齐或具有高粘土含量（Das & Zoback，2013 a; 2013 b）。Caffagni等人（2015年）的一项研究建议，在分析和解释此类事件时必须谨慎，因为区域地震可能会被误解为垂直井下地震监测阵列数据集中的LPLD事件。在这里，我们表明，在时间与这种LPLD事件相关的信号可以观察到许多地球镜USAray站，即使在距离注入井350公里。USAray的空间覆盖范围使所有LPLD事件能够重新定位在北德克萨斯州-俄克拉荷马州地区，在刺激的储层体积之外。我们的结论是，这些LPLD事件没有直接关系到水力压裂增产过程或诱导的储层变形过程。
Recent studies have identified and characterized a type of seismic event, known as an LPLD event, which have been detected in microseismic data sets acquired during hydraulic fracturing operations (e.g. Das and Zoback, 2011; 2013a; 2013b; Mitchell et al., 2013; Kwietniak, 2015). These events have been interpreted to be manifestations of slow-slip along preexisting fractures which are presumed to either be misaligned with respect to the current day principal stress directions or have high clay content (Das & Zoback, 2013a; 2013b). A study by Caffagni et al. (2015) advise that care must be undertaken when analyzing and interpreting such events as regional earthquakes could be misinterpreted as LPLD events in vertical downhole seismic monitoring array data sets. We here show that signals associated in time with such LPLD events could be observed on many Earthscope USArray stations, even at distances up to 350 km from the injection well. The spatial coverage of the USArray enabled all of the LPLD events to be relocated in the North Texas-Oklahoma region, outside of the stimulated reservoir volume. We conclude that these LPLD events are not directly related to the hydraulic fracture stimulation process or the induced reservoir deformation process.