In January and February 2015, NewTech specialists successfully completed the running and installation of expandable systems to isolate casing string leakages in the Vatyegan field, Khanty-Mansi Autonomous District – Yugra, Russia. The system comprises the following components: expanding tool, expandable casing, and expandable casing with seal. The number of expandable casing is contingent on the length of the casing leak interval. The casing with seal is installed above and below the pipes. Once it is run to a given depth (on the tubing or drill pipe), the system is activated by pumping a dart. The reaming is performed by an expandable cone mounted on the reaming tool by a combined method (using pressure applied by pumping the drilling mud and tension applied by lifting the tubing or drill pipe). The reaming will be directed from bottom to top. In the reaming process the lower and upper casing with seal gets engaged with the casing string and isolate the problem zone from the string inner space. Benefits of the Expandable Systems: The system components have threaded connections, which allows for leak isolation in a casing string of any length; The system can operate under higher loads than a casing strings and has a higher burst and crash strength; The system installation successfully addresses the issue with minimum loss of the casing inner diameter; The service life of the system installed is comparable to that of the well. The directional well “A” was suspended in 2002 because of casing leaks. The logging data identified the leak area before the installation of the expandable system in the 2096.6 – 2097.6 m interval and the wellbore leakage area, in the 2097.6 – 2118.6 m interval. A 94.19 m-long expandable system was installed in the 2072 – 2160 m interval in order to isolate the above leakage intervals. The operation effectively stopped leakages from the problem intervals. The directional well «Б» was idle since the early 2014. The logging data indicated leakages in the 1881.3 – 1884.0 m interval and the area of flawed casing in the 1874.1 – 1895.0 m interval. A decision was made to isolate the said intervals by installing an expandable system. For that purpose, a 62.95 m-long expandable system was run and installed in the 1856 – 1915 m interval. The installation was completed in a normal mode. The operation effectively stopped leakages from the problem intervals.