METHOD FOR INTEGRITY CHECK OF INTERVALS OF CASING STRING FOR INSTALLATION OF CEMENT BRIDGE IN WELLS FOR LIQUIDATION Russian patent published in 2019 - IPC E21B47/10 

FIELD: physics.

SUBSTANCE: invention relates to method of determination of tightness of main and secondary barriers in interval of installation of cement bridge in well designated for elimination. Method of diagnosing tightness of a well interval below a production packer, which includes an internal casing and an external string, tubing string and a working packer located inside the casing string, a cement ring and adjacent rocks, includes the following stages: determination of target zone of well for installation of cement bridge; temporary cement bridge installation below target zone of well; pressure testing and determining tightness of tubing and under-packer space of the wellbore based on data on constant pressure or its variation in time; creation of perforation interval in casing string and cement ring below production packer in target zone of well; performing logging during repeated pressure testing with registration of noise logging data, thermometry, flaw detection and flow metering in target zone of well; issuing conclusion on integrity of intervals of columns and cement stone for further installation of cement bridge during abandonment of well including drilling rig or repair works in certain points of non-tightness of well based on logging data.

EFFECT: technical result is high accuracy of determining tightness of barriers in well.

25 cl, 5 dwg