有扶正衬管的双层组合套管的研究

STUDY ABOUT THE DOUBLE-LAYER COMBINED CASING WITH STABILIZED LINER

一般情况下，双层组合套管的抗外挤压力大于内、外层套管的抗外挤压力之和，其充要条件是环形空间完全被水泥封固，因此固井时必须提高顶替效率。套管偏心是影响顶替效率的关键因素。为此，提出在内层套管上用衬管来固定刚性旋流扶正器的双层组合套管的新结构，一是扶正器可保证套管同心；二是水泥浆成旋流状，可进一步提高顶替效率；三是衬管也有助于提高组合套管的抗挤毁能力。

In general,the compression resistance of double-layer casing can be summed,the annulus space must be adequately cemented. So while cemented, the displacement efficiency must be increased. The casing offcenter is a key factor to effect the displacing efficiency. So,a new constructuredouble-layer casing is supplied that is fixed with a stiff spiral centralizer in the internal casing. First,thecentralizer can keep the casing centralization. Second,the cement slurry flows with spiral,the displacingcan be increased. Third,the collapsing strength of the combined casing can be increased by the liner.