PROCEDURE FOR RECOVERY OF TIGHTNESS IN FLOW STRINGS Russian patent published in 2014 - IPC E21B33/12 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to methods for recovery of tightness in flow strings. The procedure for recovery of tightness in flow strings includes surveys of the flow string leakage position and length, assembly of a sealing packer, running the packer to the well and activation of the packer. The packer mandrel is formed by screening sealing elements (elastomers) and the upper and lower leakproof elements (elastomers). The leakproof elements are divided from each other by limiting inserts. The packer is equipped with anchor bends. The packer mandrel length exceeds length of the flow string leakage. The packer is run-in to the well in run-in position when its outer diameter is more than the string drift diameter. When the packer reaches the planned interval it is activated with expansion of screening sealing elements under load up to inner diameter of the flow string and till the string and packer space is tightened against leak by the upper and lower leakproof elements below and above the seal failure interval. Limitation of the screening elements expansion is regulated due to inner limiting inserts.

EFFECT: method allows exclusion of addition of cuttings or hardened cement paste and reduction of accident rate during operation of wells.

2 cl, 1 dwg