EXPERIENCE OF COMPLETION OFFSHORE WELLS IN THE AZERBAIJANI SECTOR OF THE CASPIAN SEA
Key words: offshore well, hydraulic dual-cone liner hanger, auto-fill float shoe, auto-fill float collar, maximum allowable liner run-in-hole speed.
The technical, technological and geological conditions for well drilling in the offshore fields of the Azerbaijani sector of the Caspian Sea have a number of features, such as high reservoir pressures, the presence of loss formations, large liner installation depths and small clearances between the liner and the borehole wall. Specialists of NewTech Services LLC, participating in well casing operations with liners, apply an individual, adaptive approach to the conditions of each offshore well, which allows achieving conditions acceptable for the Customer. The experience of well casing in the fields with complicated mining and geological conditions “Umid” and “Bulla Deniz” is presented, where, in order to avoid possible jamming of the liner in the casing during running, the standard outer diameter of the liner hanger assembly was reduced without changing the strength characteristics. The applied liner casing technology in conditions of small clearances and possible troubles during the running process ensured a surging and swabbing effect decrease, string auto-filling during running, the pressure equalizing between the tubular and annular spaces, the possibility of reverse circulation in the event of well flow, well casing performing in loss formation intervals, and, ultimately, an increase of the liner run speed.