Tatneft Company widely uses its Expandable Profile Liner technology to mitigate drilling troubles. In 2008 severe lost circulationzones encountered while drilling a 124-mm. sidetrack from wells No. 207z and 5912z were shut off by 23-m and 60-m Expandable Profile Liners of P-146 type. The economic effect of application of trouble zone isolation technology using Expandable Profile Liners while drilling sidetracks amounted to RUR 392.8 thous. per well.