SIMULATION TEST OF GAS MOVEMENT IN CEMENT SLURRY

Gas channeling is a important factor affecting cementing quality and prevention of gas channeling is the main topics of this paper. After the simulation experiment device was completed, the effect of cementing additives, cement-water ratio, eccentricity of casing position, borehole inclination and rheological parameters of cement slurry on gas movement velocity were examined and these revealed that the improvement of gel strength of cement slurry is a effective measure for control of gas movement. The experiment results showed that addition of certine amount of CMC and reduce of cement-water ratio can effectively stop gas movement; assuring casing concentric position and enhancement of displacement efficiency of cement slurry can assist reduce gas movement velocity that leads to avoiding gas channeling.