A New Approach to Cure Losses by Nitrogen Foaming Technique in Cement Plugs

Abstract Lost circulation (LC) is a significant challenge in drilling operations, occurring when drilling fluids are absorbed by formations with high porosity, permeability, or fractures. LC ranges from partial to severe or complete losses, compromising wellbore stability by disrupting hydrostatic pressure. This can lead to formation gas or fluid migration, elevating the risk of blowouts. Additionally, LC inflates operational costs due to the loss of expensive drilling fluids and non-productive time spent regaining drilling fluids circulation, determining loss mitigation strategies, and incurring higher rig rates. A common solution for severe LC is to use cement plugs that quickly are set to isolate loss zones. Cement slurry fills voids and fractures, restoring circulation after hardening. However, conventional cement plugs may fail in severe loss zones. This research focuses on developing a nitrogen-foamed cement formulation that expands to seal large fractures. Tests include evaluating thickening time, linear and atmospheric expansion, and rheological properties for pumpability. Nitrogen foaming generates additional cement volume when decomposed, enhancing its capacity to seal large fractures and restore circulation. The study aims to showcase the formulation’s performance, ensuring effective LC mitigation and operational efficiency.