水泥浆中气体运移的模拟试验

SIMULATION TEST OF GAS MOVEMENT IN CEMENT SLURRY

气窜是引起固井质量问题的重要因素，如何防止气窜是本文研究的重点。在建立了简易模拟试验装置的基础上，对水泥浆添加剂、水灰比、套管偏心、井筒倾角、水泥浆流变性学数等因素对气体运移速度的影响进行了研究，认为改善水泥浆胶凝强度是阻止气体运程的有效措施。试验结果表明：在水泥浆中加入适量的CMC以及降低水灰比，可有效阻止气体的运移；施工中保证套管居中及提高水泥浆顶替效率有助于降低气体运移速度，达到防止气窜的目的。

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 ofcasing position, borehole inclination and rheological parameters of cement slurry on gasmovement velocity were examined and these revealed that the improvement of gel strength ofcement slurry is a effective measure for control of gas movement. The experiment resultsshowed 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.