定向井套管扶正器间距计算中的几个问题

SOME PROBLEMS OF COMPUTING THE INTERVALS AMONG THE CENTRALIZERS OF DIRECTIONAL WELL CASING

在定向井固井作业中，固井质量很大程度上取决于套管在井眼中的居中程度，而套管扶正器的安装间距与套管是否具有足够的居中度密切相关。很多国家都颁布了套管扶正器间距计算规范。这些规范在套管所受外载的处理上大同小异，而变形和受力的求解方法却存在相同的问题──把本属于静不定的问题作为静定问题来处理。文章重点讨论了ＡＰＩ规范和我国现行的套管扶正器间距计算方法，给出了二维计算实例，并通过分析讨论后指出，套管扶正器合理间距的确定必须在正确处理套管变形和受力模型的基础上进行。

In the course of cementing operation, the cementing quality is,to a great extent,determined by the central degree of the casing in hole. But the installation intervals of casing centralizers is closely relative to whether or not the casing has enough central degree. Many nations have issued the norms of computing centralizer intervals. The norms are very much the same in the respect of treating the case bearing capacity (the statically indeterminate problem is treated as statically deferminate one). API norms and the present methods of computing centralizer intervals in China are discussed. Two-dimensional computation example is given out, and rational determining the centralizer intervals must be done on the basis of accurately treating the casing deformation and loaded model.