In accordance with the current situation of increasing number of casing failure Wells in Liaohe oil province, study on casingpatch workover is carried out.
针对辽河油区目前套管损坏井不断增多的现状，开展了套管补贴大修技术研究。
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The casing-patch tool is lowered into the well where rubber or lead on the end of the tool is used to seal against the top of the cut casing remaining in the well.