The investigation of oil-based composition for increasing the resistance of hardening cement to aggressive effects in the plugging of the bottom hole zone

In the study use of an oil-based chemical composition to protect the cement slurry used in the reinforcement of the area around the bottom hole from the aggressive effects of the medium. The reagent "Neftqaz 2016," based on polyamine compounds and by-products of plant oil production. The proposed composition was a mixture obtained by thermally processing gossypol with polyethylenepolyamine. It was determined that the reagent had a protective effect of 98.2% in a solution containing hydrogen sulfide at concentrations of 20-100 mg/L, and the degree of annihilate of sulfate-reducing bacteria was 90%. The cement slurry for the cementing process was prepared with a water-cement ratio of 0.50. The addition of 0.006-0.024% (by weight) of "Neftqaz 2016" to the cement slurry improved the physical and mechanical properties of the resulting mass. Additionally, the oil-based mixture's impact on the spreadability, setting time, and compressive strength of the cement stone under aggressive conditions, such as hydrogen sulfide gas, was investigated. It was shown that under normal conditions, as the percentage of "Neftqaz 2016" reagent increased in the dispersion medium, the parameters of both the cement slurry and the resulting cement mass improved. This increase in spreadability was explained by the partial interaction of water molecules, which were essential for the hydration of cement components, with the functional groups of the reagent via hydrogen bonding. Keywords: cement slurry: plant oil; injection; plugging; bottom hole; setting time; compressive strength.