Evaluation of Thickening Time of Oil Field Class G Cement Slurry at High Temperature and Pressure Using Experimental Design - TI Journals

Abstract: The main objective of cementing technology is to cement casing string so as to facilitate zonal isolation necessary to drill further or control production. To achieve this objective slurries are design by adding certain additives to control density, filtration loss and pumpable/thickening time needed for slurry placement. Thickening time was evaluated at 6000psi and 400oC using Experimental Design. Four factors which include extender, accelerator, antifoam and dispersant was considered at two levels. Sixteen experiments were conducted with the response replicated twice. The analysis was done using Yates algorithms to determine the influence of different parameters on the thickening time. A regression equation was developed for pumpable time as a function of the dependent variables. The model developed has a correlation coefficient, R2 of 0.9998, coefficient of variance of 0.0000697 and standard error of 0.08838. The model is simple and easily programmable for initial estimations on the field.