EXPERIMENTAL STUDY ON ULTRALOW DENSITY BLAST-FURNACE SLAG MTC CEMENTING SLURRY

The problems of insufficient cement flowback and poor cementing quality still exist, even though the low density of 1.30-1.50 g/cm3 cementing slurry is used in the low pressure formation and thief zone of Jing’an, Hauchi and Zhengyuan areas, Changqing Oilfield. Based on advantages of MTC cementing technique, the ultra-low density of 1.20-1.40 g/cm3 blast-furnace slag MTC cementing slurry system is developed with blast-furnace slag, light weight material of floating balls and alkaline activating agent, to solve the problem of cementing quality in the low pressure formation and thief zone. The developed ultra low density blast-furnace slag MTC cementing slurry possesses good rhelogical properties and stable system. It’s thickening time may meet the requirement of cementing operation. It has high pressure strength both at low temperature and high temperature. The blast-furnace slag activating agents of BES-1 and BES-2 possess good performance, and can activate slag and floating balls both at low temperature and high temperature to increase the pressure strength of ultra-low density slag MTC cementing slurry.