The flushing fluid is a liquid pumped before cementing to flush the wellbore wall and mud cake adhesive on casing, while there is no standard evaluation method to evaluate the cementing flushing efficiency. On the basis of analyzing several evaluating methods, the paper described a new method for evaluating the flushing efficiency according to the relation between viscosimeter rotary speed and shear rate. The viscosimeter was modified based on the measuring principle, and the testing procedure was determined. Three different flushing fluids were evaluated using the proposed testing method. The results show that this method is simple with less human error, has good comparison and repeatability, and is more objective and practical which can provide useful reference for field application. However, due to viscosimeter's structure constraints, flushing efficiency cannot be measured accurately which requires further improvement.%冲洗液是在注水泥浆前预先泵入的一段流体,用以冲洗附着在井壁和套管壁上的浮泥饼.但是目前就固井冲洗液的冲洗效率评价,国内外还没有形成统一的标准、方法和手段.在分析常用几种评价方法优缺点的基础上,根据旋转黏度计测量原理中转速与壁面剪切速率之间的关系,提出了一种新的冲洗效率评价方法.根据旋转黏度计的测量原理对旋转黏度计进行了改造,并确定了评价冲洗效率的试验步骤.利用改造后的旋转黏度计,根据评价试验步骤评价了3种固井冲洗液的冲洗效率,结果表明,该评价方法操作简单、人为误差小、对比性强、可重复性好、更客观实用,可以为现场施工提供有力的参考数据.但由于旋转黏度计构造的限制,无法精确测得冲洗效率,因此,需对该方法进行进一步改进.
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