Development of new geopolymer material as alternative plug for cement in CO₂ sequestration

Maintaining CO₂ in gas and oil wells is a challenge in CO₂ sequestration. The downhole forces on the pumped cement between the casing and the drilled formation lead to failure of cement, and hence the well integrity can be affected. Furthermore, the prolong interaction between the stored CO₂ and the casted cement can lead to corrosion of embedded well tubulars. This deterioration of the casted well is a major cause of cracking and channeling of the cement matrix resulted in early gas migration. Such problems can lead to early workover jobs or shutting-down some wells that resulted in losing its productivity. This work aims at developing a new material from clay that has a high resistance to CO₂ in upstream for plugging CO₂ storage wells. The synthesis conditions as well as the adsorption-desorption characteristics at simulated well condition will be presented. Then a model that simulates the adsorption isotherms and the thermodynamic properties for the interaction between the developed material and the CO₂ will be investigated. The developed material demonstrated lower porosity and permeability, and higher compressive strength than the conventional cement plug. Thermogravimetric and thermal stability of the developed geopolymer sample showed a minimal variation in weight loss with incremental heating up to 420°C. Adsorption-desorption of CO₂ at various modeled temperature showed an endothermic and spontaneous process with maximum adsorption capacity of 800 mg/g obtained at 660 psi. Higher pressure lead to more storage capacity with physisorption hysteresis curves. The novelty of this work is the development of new geopolymer material that can substitute the conventional cement plug for upstream carbon capture and sequestration.