Sammendrag
Ordinary Portland Cement (OPC) is the primary binder material used for primary cementing and plug and abandonment (P&A). This material has many advantages and some shortages, and it is well-studied when it comes to its properties. However, OPC consumes a large amount of raw material and energy for the calcination of limestone. It is responsible for a considerable amount of carbon dioxide (CO2) emission and other greenhouse gasses. Hence, OPC is not an environment-friendly binder; several studies and investigations have been done to find a greener and suitable alternative for OPC.
Geopolymers are inorganic polymers and have binding properties with a network structure of aluminum and silicate. Studies have shown that geopolymer is an excellent alternative for OPC, thus having properties such as stability at elevated temperatures, lower Young’s modulus, longer durability, a lower degree of chemical shrinkage, and lower permeability compared to OPC. However, controlling its pumpability is the current limitation that keeps geopolymers from being applied in the oilfields. For removing this current limitation and improving pumpability of the geopolymer slurry, retarding admixtures are added to delay the thickening of the slurry, while minimizing its setting time.
This study presents the impact of admixtures on pumpability and short-term mechanical properties of rock-based geopolymer cement (GPC). The properties that are analyzed include workability, setting time, and uniaxial compressive strength. Following additives are investigated throughout this study:
• Magnesium oxide (MgO)
• Sucrose
• Zinc & Potassium (Zn & K)
• Alumina oxide (Al2O3)