Comparative analysis of the geopolymer and Portland cement application as plugging material under conditions of incomplete displacement of drilling mud from the annulus

Abstract

Portland cement is traditionally used in cementing of oil and gas wells. However, Portland cement has a number of shortcomings. The most important of these are the formation of microannuli between the cement plug and the rock or casing, as well as the formation of cracks and permeable channels in the cement matrix. Recent research shows that geopolymer can be a perspective alternate to portlandcement by overcoming beforementioned issues. The article comparatively analyzes the changes in the parameters of plugging materials containing geopolymer and Portland cement while contamination with water-based drilling mud. The results show that geopolymerbased solutions are more resistant to contamination with water-based drilling mud than Portland cement-based solutions. Thus, mixing Portland cement slurry with water-based drilling mud increases its viscosity and fluid loss, and sharply reduces its compressive strength. However, when a geopolymer solution is mixed with a water-based drilling fluid, its viscosity is almost unchanged, its fluid loss is reduced, and reduction in its compressive strength is less than in Portlandcement based material. Keywords: portland cement; geopolymer; fly ash; cementing; water based mud; mud contamination.