Abstract Geothermal formations are naturally fractured with large fracture openings and networks. This can often lead to frequent drilling fluid loss events which is a major contributor to the cost and non-productive time in geothermal drilling. Development of smarter technologies and methods to tackle problem lost circulation is vital for geothermal drilling cost reduction required for geothermal energy to be recognized as a competitive alternative energy source. Mitigation of this problem and other drilling problems such as stuck pipe can minimize overall project cost. In this paper, a thermoset shape memory polymer that can be activated by formation natural heat was assessed to seal near wellbore fractures in geothermal wells. The performance of the shape memory polymer (SMP) was evaluated using artificial fractures created in aluminum discs and cylindrical granite cores. Rheology and particle size distribution were considered. A novel testing setup was built for this work, which allows testing of sealing efficiency under dynamic conditions at high temperature. Analysis showed that the SMP has efficiently succeeded in forming a strong plug inside the fractures and stopped fluid loss at high sealing pressure. This smart loss circulation material can expand within the fractures to reduces non-drilling time and strengthen the wellbore in high-temperature drilling operations.

中文翻译：

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形状记忆聚合物在地热钻井中防堵漏

摘要 地热地层具有大的裂缝开口和网络。这通常会导致频繁的钻井液流失事件，这是造成地热钻井成本和非生产时间的主要因素。开发更智能的技术和方法来解决漏失问题对于降低地热能被公认为具有竞争力的替代能源所需的地热钻井成本至关重要。缓解这个问题和卡住管道等其他钻井问题可以最大限度地降低整体项目成本。在本文中，评估了一种可以被地层自然热量激活的热固性形状记忆聚合物，用于密封地热井中的井眼裂缝附近。形状记忆聚合物 (SMP) 的性能使用在铝盘和圆柱形花岗岩芯中产生的人工裂缝进行评估。考虑了流变学和粒度分布。为这项工作建立了一种新颖的测试装置，可以在高温动态条件下测试密封效率。分析表明，SMP 有效地成功地在裂缝内形成了一个坚固的塞并在高密封压力下阻止了流体损失。这种智能堵漏材料可以在裂缝内膨胀，以减少非钻井时间并在高温钻井作业中加强井筒。它允许在高温动态条件下测试密封效率。分析表明，SMP 有效地成功地在裂缝内形成了一个坚固的塞并在高密封压力下阻止了流体损失。这种智能堵漏材料可以在裂缝内膨胀，以减少非钻井时间并在高温钻井作业中加强井筒。它允许在高温动态条件下测试密封效率。分析表明，SMP 有效地成功地在裂缝内形成了一个坚固的塞并在高密封压力下阻止了流体损失。这种智能堵漏材料可以在裂缝内膨胀，以减少非钻井时间并在高温钻井作业中加强井筒。