Safe sealing technological research on bayonet-tube string

Aiming at problems encountered in using plug sealing technological string K344 such as “flag erecting sausage stuffing” serious accidents, plugging agent being easy flow back, and existed bayonet-tube packer being poor pressure resistant and difficult drilling and removing, a research on safe sealing technological string with bayonet-tube has carried out. The newly safe plugging string is composed of novel bayonet-tube drillable bridge plug, setting tool, bayonet tube and centralizer. After ash injection, the bayonet tube could be rapidly pulled out and then the injection channel could be shut down to prevent the plugging agent flow back, which could avoid most of the accidents. The special sealing method of bayonet-tube tools and specific design of drilling and grinding tools with drillable bridge plugs greatly enhance the pressure resistant index and drillability of packers. Field application of this technological string has showed good effect and obviously increased the safety of sealing construction.