不同套管-井眼组合下旋转套管速度分析研究

Reasonable Casing Rotary Speed under Different Casing-Wellbore Dimensional Assembly

旋转套管可以有效提高水泥浆顶替效率,从而提高固井质量。根据旋转套管理论模型及粘性不可压缩液体的运动方程,推导出了不同套管-井眼组合条件下套管旋转产生的径向速度分布计算公式,并计算了在不同套管-井眼组合条件下旋转套管时流体径向速度分布。结果表明,环空间隙越小,其因旋转引起的速度下降沿径向衰减速度越平缓,旋转套管效果越好,证明旋转套管对提高小间隙固井质量意义更大。

Rotating casing is helpful to improve effectively mud displacement efficiency and thus improve cementing quality. According to the theoretical model of rotating casing and continuous and kinematic equations, the formula to calculate radial velocity induced from casing rotation has been developed under various casing-wellbore dimensional assemblies. Actual radial velocity distribution, that have been calculated, indicate that the narrower the annulus, the slower the decrease gradient of the velocity at radial direction caused by rotation, and thus a better rotational effectiveness. Above conclusion proves that rotating casing is significant to improve cementing quality with slim annulus.