Current development of process equipment targets to find the best solutions to reduce duration of well intervention operations relative to the number of well workovers from 91 to 80 hours per job by 2030. Analysis of well servicing costs saving potential has revealed several disadvantages of the existing flanged connections including complexity, labor intensity and long duration of assembling. Another drawback is poor reliability by reason of failure to provide uniform tightening of the nuts on studs to produce pressure-tight flanged connections without using special tools to ensure specified tightening force of connections. In light of the above, improved flange bolting designs have been developed.
TatNIPIneft’s engineers have developed flange bolting for producing wells differing in the number of fasteners and grade of the manufacturing material. These flange boltings are suitable for various types of wellhead assemblies used in TATNEFT’s producing wells. The new flange bolting reduces labor intensity of assembly operations and improves flange bolting reliability to eliminate loss of their function, particularly the necessity to regularly tighten the nuts due to segmented elements on the stud bolts, which being in contact, prevent their spinning. The apparent benefits of the flange bolting under consideration include reduced duration of assembly and disassembly, as well as reliability and versatility. The new flange bolting has been successfully tested in six producing wells. It is recommended to be added to TATNEFT’s best practices.
References
1. Сборник унифицированных норм времени на текущий ремонт скважин: НМД 293-06-553-2016, ЕРБ 01-893-1.0-2016 (Collection of unified norms of time for current workover of wells: NMD 293-06-553-2016, ERB 01-893-1.0-2016), Альметьевск: Publ. of PJSC TATNEFT, 2016, pp. 37–40.
2. Patent RU 2753224 C1, Flange connection of wellhead equipment (Options), Inventors: Зиятдинов Р.З., Насрыев Р.И.
3. Patent RU 2760446 C1, Method for fastening a flange connection with studs with segment elements and a device for its implementation, Inventor: Зиятдинов Р.З.
4. Birger I.A., Iosilevich G.B., Rez’bovye i flantsevye soedineniya (Threaded and flanged connections), Moscow: Mashinostroenie Publ., 1990, 388 p.
