Rahmatullah Idham K, Ahmed Abdulmalek, Elkatatny Salaheldin, Abd El Fattah Ahmed M
Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.
Department of Architecture, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.
Sci Rep. 2025 Jul 1;15(1):20965. doi: 10.1038/s41598-025-06865-2.
Geopolymer cement represents an innovative and environmentally friendly cement system that utilizes non-portlandite precursors to achieve cement hardening. Unlike traditional Portland cement, which accounts for approximately 5-8% of global CO₂ emissions, geopolymer cement offers a sustainable alternative. While its use has been widely adopted in construction projects, its application in wellbore cementing remains limited. Beyond reducing CO₂ emissions, geopolymer cement optimizes waste management by incorporating rock-based or industrial by-products rich in aluminosilicate content. In this study, Saudi volcanic scoria was developed as the primary binder for lightweight geopolymer wellbore cement. By varying the concentration of sodium hydroxide (NaOH) as an alkali activator from 15 to 40%, lightweight geopolymer cement was produced without the addition of external additives. The geopolymer cement sample containing the optimum concentration of NaOH was then used as a benchmark and compared to traditional Portland cement under identical conditions. Key variables such as mechanical strengths, rheological properties, free water, and sedimentation were analyzed. Experimental results demonstrated that volcanic scoria-based geopolymer cement with 20% NaOH achieved optimal performance, with the highest compressive and tensile strengths of 1798 psi and 73.9 psi, respectively. The results revealed that the geopolymer cement outperformed Portland cement in several aspects. For example, its compressive strength was 56% higher than that of Portland cement. Furthermore, the elastic properties of geopolymer cement were superior, with a 47% lower Young's modulus than Portland cement. Rheological evaluations indicated that geopolymer cement exhibited excellent pumpability and workability. Despite its plastic viscosity being higher than Portland cement, the geopolymer cement demonstrated 180%, 200%, and 336% higher yield points, 10-second gel strengths, and 10-minute gel strengths, respectively. Geopolymer cement performed exceptionally well in terms of stability, with 96% less free water and a 14% lower density variation than Portland cement. These findings highlight the potential of Saudi volcanic scoria as a primary binder in lightweight geopolymer cement. By applying the one-part method, the volcanic scoria-based geopolymer cement becomes a prospective environmentally friendly cement that can potentially be used in wellbore operations. It offers a viable solution that mitigates the carbon emissions while meeting the technical requirements for wellbore cementing applications.
地聚合物水泥是一种创新的、环保的水泥体系，它利用非波特兰石前驱体来实现水泥硬化。与占全球二氧化碳排放量约5-8%的传统波特兰水泥不同，地聚合物水泥提供了一种可持续的替代方案。虽然它已在建筑项目中广泛应用，但其在井筒固井中的应用仍然有限。除了减少二氧化碳排放外，地聚合物水泥通过掺入富含硅铝酸盐成分的岩石基或工业副产品来优化废物管理。在本研究中，沙特火山浮石被开发为轻质地聚合物井筒水泥的主要粘结剂。通过将作为碱活化剂的氢氧化钠（NaOH）浓度从15%变化到40%，在不添加外部添加剂的情况下生产出了轻质地聚合物水泥。然后将含有最佳NaOH浓度的地聚合物水泥样品作为基准，并在相同条件下与传统波特兰水泥进行比较。分析了诸如机械强度、流变性能、自由水和沉降等关键变量。实验结果表明，含20%NaOH的基于火山浮石的地聚合物水泥性能最佳，其抗压强度和抗拉强度分别最高可达1798 psi和73.9 psi。结果显示，地聚合物水泥在几个方面优于波特兰水泥。例如，其抗压强度比波特兰水泥高56%。此外，地聚合物水泥的弹性性能更优，其杨氏模量比波特兰水泥低47%。流变学评估表明，地聚合物水泥表现出优异的泵送性和可加工性。尽管其塑性粘度高于波特兰水泥，但地聚合物水泥的屈服点、10秒凝胶强度和10分钟凝胶强度分别高出180%、200%和336%。地聚合物水泥在稳定性方面表现出色，其自由水比波特兰水泥少96%，密度变化比波特兰水泥低14%。这些发现突出了沙特火山浮石作为轻质地聚合物水泥主要粘结剂的潜力。通过采用单组分方法，基于火山浮石的地聚合物水泥成为一种有前景的环保水泥，可以潜在地用于井筒作业。它提供了一个可行的解决方案，既能减少碳排放，又能满足井筒固井应用的技术要求。
