Effect of naphthalene dispersant on the hydration kinetics of cement slurry: Nuclear magnetic resonance-based investigation

Cementing technology can effectively extend the life of coalbed methane surface drilling. The fluidity cement slurry during cementing is critical to quality. It an effective way improve quality by increasing and pumping efficiency paste adding dispersants. In this paper, effect naphthalene dispersant on hydration kinetics G-grade was investigated nuclear magnetic resonance. results show that increase mass fraction slow down cement. first relaxation peak correlated with its mobility, calculation index, area size, share combined action factor be used evaluate retarding dispersing more accurately. main effects are: causes in ξ potential particles, which makes barrier overcome particle coalescence rise; sulfonic acid group form a stable complex Ca2+, resulting reduced rate. Naphthalene decompose into anions adsorbed forming solvation film producing lubricating dragging effect. obtained research provide theoretical support for preparation on-site from three aspects: modified slurry, how choose period.