The proppant embedment due to creep in shales is a known issue affecting the useable lifetime of wells in unconventional oil and gas recovery. One of the factors influencing creep is the presence of organics, whose properties can be very sensitive to temperature. In this work we investigated for the first time the role of temperature-induced creep increase in proppant embedment in an organics-rich Green River oil shale sample via in-situ synchrotron X-ray micro-computed tomography. We observed that temperatures as low as 75 °C already induce fast creep, with a fracture aperture closing rate of 13 μm/h and a loss of fracture conductivity rate of 8.7%/h, due only to proppant embedment, in the measured interval at the first heating stage. Local displacement data analysis provided evidence for markedly plastic deformation around the proppant-shale contacts, in contrast with the brittle proppant embedment observed on more cemented and less organics-rich shales at room temperature. The results highlight how the problem of temperature-dependent mechanical behavior might be more important than previously thought, in shales with a high content in organics, and that in-situ micro-imaging techniques can play a key role in understanding the underlying mechanisms, contributing to solve creep-related problems associated with hydraulic fracturing in complex scenarios.

页岩蠕变引起的支撑剂包埋是一个已知问题，它会影响非常规油气采收井的使用寿命。影响蠕变的因素之一是有机物的存在，其性质可能对温度非常敏感。在这项工作中，我们首次通过原位同步加速器X射线微计算机断层扫描技术，研究了温度诱导的蠕变增加在富含有机物的绿河油页岩样品中支撑剂包埋中的作用。我们观察到，在75°C的测量间隔内，低至75°C的温度已经引起快速蠕变，裂缝孔的闭合速度为13μm/ h，裂缝电导率的损失仅由于支撑剂嵌入而降低了8.7％/ h。第一加热阶段。局部位移数据分析提供了支撑剂-页岩接触周围明显塑性变形的证据，而在室温下，在水泥含量较高且有机物含量较低的页岩中观察到脆性支撑剂的嵌入。结果表明，在有机物含量高的页岩中，与温度有关的机械行为问题可能比以前认为的更为重要，并且原位微成像技术可以在理解潜在机理中起到关键作用，解决复杂场景中与水力压裂有关的蠕变相关问题。