改性钻井泥浆固化的试验研究

Study on the Solidification of Modified Drilling Fluid

用压出法测定了在模拟井下温度条件下养护的固井材料与不同组成的泥浆所浸泡的模拟岩芯之间的二界面粘结强度,同时用XRD和SEM研究了二界面上的水化产物和显微结构.试验结果表明,纯泥浆与堵剂间无法形成有效的粘结,而掺加高钙粉煤灰的泥浆内部可以发生轻微的水化硬化反应,使其与堵剂很好地固化成一体,形成一个良好的粘结层.使用掺加高钙粉煤灰的改性泥浆浸泡岩芯,其二界面粘结强度可比纯泥浆浸泡的岩芯提高2倍以上.

By using pushout method, the bonding strength between cementing plug and simulated rocks emerged in fluids with different components were measured in similar temperature condition under oilwell. The hydration products and microstructures of the interface between hardened sealant and rock were investigated by XRD and SEM. The results indicate that the pure fluid can not forming efficient bonding strength, however, slightly hydrating and hardening reactions take place inside the drilling fluids modified with high calcium fly ash. It can form a good bonding layer and solidify with cementing plug. The interface bonding strength of the rocks immersed by the modified drilling fluid mixing with high calcium fly ash can increase to be about 3 times as that immersed by pure fluids.