Meeting future net-zero carbon energy needs: Improved borehole sealing using compacted bentonite and silica grout.

井眼退役和弃井需要长期密封潜在的流体运移通道。核废料服务公司最近在Harwell进行的现场试验表明，在密封材料放置之前，邻近的墙有塌陷到井眼中的趋势。该项目旨在通过研究井眼密封新技术来提供解决方案，以防止储存在地下深处的流体向上泄漏。研究重点是硅基注浆材料与膨润土结合的潜力，以稳定和密封薄弱和/或破碎岩柱的钻孔。通过实验，该研究旨在优化胶体硅浆液的组成，并研究膨润土和胶体硅浆液界面上的任何化学和物理相互作用。因此，产出将提供长期钻孔密封性能的数据和模型，为地质处置设施的环境安全案例提供信息。

Borehole decommissioning and abandonment requires the long-term sealing of potential fluid migration pathways. Recent field trials at Harwell by Nuclear Waste Services revealed a tendency of adjacent walls collapsing into the borehole before sealing materials are emplaced. This project seeks to provide a solution by investigating new technologies for borehole sealing to prevent upward leakage of fluids that are stored at-depth in the ground.The research focuses on the potential for silica-based grouting materials in conjunction with bentonite to stabilise and seal off boreholes in weak and/or fractured rock columns. Through experimentation, the research seeks to optimise the colloidal silica grout composition, as well as, investigate any chemical and physical interactions at the interface between the bentonite and the colloidal silica grout. The output will thus provide data and models of long-term borehole seal performance to inform the Environmental Safety Case for a Geological Disposal Facility.