Development of One-Part Rock-Based Geopolymers for Downhole Cementing Applications

The use of geopolymers as a full replacement for cement in oil well cementing applications requires the development of not only environmentally friendly but also user-friendly cementitious materials. This study aims to investigate the early-age mechanical and chemical properties of synthesized one-part geopolymers, which are heat-cured rock-based products. These geopolymers were synthesized from granite-based precursors and were activated by solid powders of potassium silicate, with a small portion of potassium hydroxide (KOH) as an accelerator to enhance the setting time and early strength. The mechanical and chemical properties of the one-part geopolymers were characterized, and the mineralogy of the solidified samples was analyzed through crystallography to better understand their microstructure. The study found that the investigated one-part geopolymer mixes, which were activated by a solid activator with a modulus ratio of 2.4, developed acceptable compressive strength of around 7 to 13 MPa within 24 hours and up to 7 days. The use of one-part geopolymers has the potential to provide environmentally- and user-friendly slurries that can facilitate their utilization for large-scale in-situ applications in the petroleum and civil engineering sectors.