The Effect of Gas Migration on Cement Sheath Integrity

ABSTRACT
An Important phenomenon that can have a major impact on wellbore integrity and overall operating safety in oil and gas wells is gas migration within cement sheaths. Gas migration refers to the movement of gas within the subsurface layers of the earth, particularly in the oil and gas wells. Most sources identify the main reason that gas migration occurs is due to the reduction in hydrostatic head as the cement slurry begins to hydrate, where the formation gas pressure exceeds the hydrostatic pressure in the cement slurry pores This research work investigated the impact of gas migration on cement sheath integrity over varying transition times. This project reviewed how transition periods influence the mechanical and structural properties of the cement barrier, analyzing the dynamic relationship between gas movement and cement slurry properties which is crucial for understanding long term wellbore stability. Through experimental simulation and data analysis, insight into dynamic nature of gas cement interactions, providing valuable insight for designing and maintaining effective well bore sealing against gas penetration through gas check additive (Halad 344) was achieved. The result obtained showed that through an increase in gas check additive on the cement slurry, the transition time was reduced which in turn enable the slurry to be able to resist gas penetration.