Abstract:
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 constructure double-layer casing is supplied that is fixed with a stiff spiral centralizer in the internal casing.First,the centralizer can keep the casing centralization.Second,the cement slurry flows with spiral,the displacing can be increased.Third,the collapsing strength of the combined casing can be increased by the liner.