A new combination of ether and ester as FLC with a liquid dispersant for decreasing the transition time and optimization of fluid loss and rheological properties of fresh cement slurry

Abstract

Fluid loss causes the rheological properties and mechanical properties of the slurry to change completely. Therefore, fluid loss proves that the slurry cannot have proper properties. In this study, the effect of several types of FLC (Fluid loss control) and a liquid dispersant on the fresh cement slurries are considered. the change in rheological properties, compressive strength, Fluid loss control, free water, settling, mixing time, and thickening time were investigated. Also, a challenging issue during well cementing in the oil well is fluid migration from the pumped cement into the permeable formation. Excessive fluid loss can create space for gas entry into the cement slurry, hence fluid loss control additives are also utilized to reduce gas migration. The cement slurry weight was 118 pcf used in 13 3/8” casing and 7” liners. An FLC composed of two substances (including ester-ether) was selected after examining materials with amide, ester, ether, alcoholic, and carboxylic acid functional groups. The ultimate recommendation introduced a combination of three substances (FLC1+FLC2+Liquid Dispersant) as proposed materials for controlling the mentioned properties in the slurry of fresh cement at 180℉ and 210℉ for compressive strength and 150 ℉ and 180 ℉ for BHCT slurry characteristics. The designed formulation using these additives leads to a reduction in transition time. The reduction in transition time plays a significant role in decreasing gas migration into the cement slurry.