Failure typical cases of interpolation cementing tools and preventive measures

Interpolation cementing technique is specifically used for large-size casing or surface casing. This technique can save time and have a little displacement, so it is extensively used in cementing ?339.7 mm casing in a salt cavern gas storage. With the increase of operation activities, the auxiliary tools for interpolation cementing job often fail due to various reasons, but the subsequence is very severe, affecting the next drilling procedure. Examples were taken to analyze the cases of failure of auxiliary tools for cementing ?339.7 mm casing in a salt-cavern gas storage using interpolation cementing technique, and the causes for the failure were analyzed in terms of tool structure and working principles. Also, the relevant preventive measures were presented, all of which were of some reference value to field cementing jobs.