Ali Allahverdi - Department of Chemical Engineering, Iran University of Science and Technology, Iran
Ebrahim Najafi Kani - Department of Chemical Engineering, Iran University of Science and Technology, Iran
Shadi Soltani - Department of Chemical Engineering, Iran University of Science and Technology, Iran

In this paper, effects of particle size distribution improvement and dense packing technique on compressive strength of class G oil well cement have been investigated. It was observed that limited improvements in particle size distribution at about industrial possibilities can not result in a significant increase in 28- and 90-day compressive strength. Microsilica and limestone powder with grain size less than 45 micrometers can not be utilized as a substitute for cement for improving the compressive strength of class G oil well cement, because any addition of these materials will simultaneously result in shortening of setting times. Utilization of quartz powder, as an inert filler, and at optimum substitution percentages, i.e. around 6 to 10% by weight, however can result in almost 7% increase in 28-day compressive strength of hardened paste of cement without any considerable effect on setting times.

Class G oil well cement, Particle size distribution, Dense packing