The Application of Eccentric Mechanical Vibration Cementing Technique in Changqing

An eccentric mechanical vibration cementing technique was used in Changqing oilfield in an effort to improve the cementing job quality of the injector wells. Cementing slurry was evaluated after vibration on a ZD-34 model electric vibrator as to its compressive strength, bond strength, thickening time, initial setting transition time, final setting transition time, and permeability. The evaluated cement slurry was then used in filed operations. The laboratory study showed that the thickening time of the cement slurry after vibration was reduced by 25%-30%, the initial and the final setting transition time reduced by 30%-50%, the 24 h strength of the set cement increased by 10%-14%, the bond strength increased by 11%-16%, and the permeability reduced by 33.3%-43.9%. This technique has been used in 5 wells in the block Wupu in Changqing oilfield, and the oil zones and water zones in these wells are well separated, with the rate of excellent well cement jobs increased by more than 20%. The laboratory experiments and the field applications all demonstrate that the eccentric mechanical vibration cementing technique can effectively enhance the quality of well cementing, and is prospective in future cementing operations.