Techniques to estimate fracture effectiveness when mapping low-magnitude microseismicity
Techniques to estimate fracture effectiveness when mapping low-magnitude microseismicity
复制标题
绘制低震级微震活动图时估计裂缝有效性的技术
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
R. Billingsley
中科院分区：
文献类型：
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作者：
Sherilyn Williams;R. Billingsley
通过定位与岩石压裂相关的微地震事件进行水力裂缝测绘，可用于评估低渗透油藏增产措施的有效性。事件的几何形状用于推断裂缝方向，特别是在事件沿方位角排列或在三维空间中具有平面分布的情况下。当诱发微地震事件的信噪比较低时（由于震级低或传播效应），其位置可能具有高度的不确定性。低信噪比事件在储层中无法准确定位，或者根本无法检测到，因此可能低估了裂缝改造储层的程度。在Williston盆地Bakken组中，我们将地质分析与基于过程的随机裂缝建模相结合，建立了多种可能的裂缝模型实现。可以修改模型中的特定参数，同时尊重每个参数的实际范围，以探索不确定性的范围。通过历史匹配迭代验证由裂缝模型生成的裂缝流动特性。反过来，经过验证的裂缝模型提供了一种计算岩石几何约束体积和裂缝渗透率的方法，可用于估计产量。本文提出了一种确定哪些裂缝参数（高灵敏度参数）可以改变的方法，以尽量减少在油藏模拟程序的模型调节阶段需要产生的实现数量。
Summary Hydraulic fracture mapping by locating microseismic events related to rock fracturing is used to evaluate the effectiveness of the stimulation in low-permeability reservoirs. The geometry of the events is used to infer fracture orientation, particularly in the case where events line up along an azimuth, or have a planar distribution in 3 dimensions. When the induced the microseismic events have a low signal-to-noise ratio (either due to low magnitude or propagation effects) their locations can have a high degree of uncertainty. Low signal-to-noise events are not as accurately located in the reservoir, or are not detected at all, so that the extent of fracture stimulated reservoir may be underestimated. In the Bakken Formation of the Williston Basin, we combine geological analysis with process-based and stochastic fracture modeling to build multiple possible fracture model realizations. Specific parameters in the models can be modified while honoring a realistic range for each parameter in order to explore the range of uncertainty. Fracture flow properties generated from the fracture models are validated via history matching iterations. The validated fracture models, in turn, provide a means to calculate a geometrically-constrained volume of rock and fracture permeability that can be used for estimating production. This paper presents a methodology for deciding which fracture parameters to vary (the high sensitivity parameters) in order to minimize the number of realizations that need to be generated during the model conditioning phase of a reservoir simulation program.