The patented device is used for drilling, cementing and workover of oil and gas wells and allows creating a tight connection of casing strings of multilateral wells and downhole splitters of the sixth complexity level according to the TAML classification.

A feature of this method is the performance of connections at the factory, which significantly increases their reliability and the possibility of using them in wells with casing strings of 168 and 146 mm diameters.

The technologies were of expanding pipes developed at TatNIPIneft have been applied in the implementation of the technical solution, which are widely used to iso-late zones of complications in the drilling of wells.

The authors of the invention are the professionals of the TATNEFT’s TatNIPIneft Company A.A. Mukhametshin, F.F. Akhmadishin, A. L. Nasyrov.