EFFECTIVNESS OF ADDING CELLULOSE ETHER DURING GRINDING PROCCESS OF OIL-WELL CEMENT

Abstract

The article describes studies of effectiveness adding cellulose ethers during grinding process of oil-well cement. During researches was used a number of percentage ratios to clarify the real impact of adding cellulose ethers to the oil-well cement. The ratio is 0%; 0,02%; 0,035%; 0,05%; 0,25%, 0,5%. The effectiveness of cellulose ether is affected by its dosage. When 0,02% of cellulose ether is added during cement grinding observed a significant decrease in water separation and there is no loss of spreading. When cellulose ether is added in an amount from 0,02% to 0,035% of the cement quantity, a decrease in water separation is observed along with a decrease in spreading. Cellulose ether increases the adhesive force between particles, which allows to reduce their sedimentation, and accordingly, water separation, as well as reduce the spreading of cement. When cellulose ether is added in amounts greater than 0,25% by weight, there are a significant decreasing in water separation and its absence, but such cement does not meet the flow standards, and it also does not behave characteristically during molding. During forming samples of cement mortar including cellulose ether from 0,05% to 0,5% are observed intensive air entrainment and respectively increasing in porosity and volume. With increased dosage of cellulose ether observed decreasing in strength parameters. Any dosage of cellulose ether does not reduce the thickening time of cement paste to the critical value of 90 min. This study opens up a possible way to control the sedimentation process while maintaining the necessary spreading and other physical and mechanical properties of the oil-well cement paste. It is sufficient to add cellulose ether up to 0,02%. In this case, the water separation index decreases from 8.5 ml to 5.5 ml and the plasticity of the cement mortar is maintained, which corresponds to a spreading index of 220 mm.