The Thickening Time of Ferrous Cement Slurry System in High-Pressure and High-Temperature Environment

Abstract

Experimentally, the aim of this research paper is to investigate the thickening time (TT) of different ferrous cement slurry systems in high-pressure and high-temperature (HPHT) environment. Objectively, the study collected eight (8) samples of groundwater from 8 different boreholes, as mix-water, from the study area, Kolo Creek. These mix-water samples were subjected to water chemistry analysis, based on the American Public Health Association (APHA) drinking water test methods; the results obtained from these tests were benchmarked with the standard values of World Health Organisation (WHO), and Nigeria Standard Drinking Water Quality (NSDWQ) standards. These results reveal that, in each of the tested mix-water samples, ferrous ion (Fe2+) concentration was higher (0.52 to 6.82mg/L); which is greater than 0.3mg/L, and this was the only chemical parameter that was in strong disagreement with the WHO’s and NSDWQ’s Drinking Water Quality standards. Subsequently, each of these ferrous mix-waters were used in the formulation of cement slurries at the water-to-cement ratio of 0.44 in batches; each of these formulated slurries were used, to test for the effects of ferrous ion concentration in mix-water on the TT performances of the slurries. These TT tests were performed using the Chandler model 7322 HPHT Consistometer. These tests were conducted based on the API Specification 10A methods of 1995. Generally, the results obtained reveal that, as the concentration of Fe2+increases in the mix-water, the TT of the cement slurry accelerated in the HPHT environment. This means that the cement slurry set faster. Also, this set-fast behaviour of high ferrous ion concentration towards slurry suggested that, high concentration of ferrous ion induced the exothermic reaction of tricalcium aluminate (C3A) during the hydration of the ferrous cement slurry. Therefore, ferrous neat cement slurry is only suitable for cementing shallow oil-well, except retarding additives are added into the slurry.

Improving the sustainability of oil well cementing operations: blending Portland cement with pozzolana

“…According toAbbas et al (2014),Igbani et al (2020) andZahid et al (2018), the plastic viscosity of slurry must be less than 100 cP, which is desirable to keep cement slurry flowing and pumpable at 65 °C. It was identified inFig.…”