TatNIPIneft engineers have developed the procedure to control formation caving and sloughing in horizontal wells with expandable profile liner of PBI–144/130 type, which is set in a well per one trip and consists of expandable profiled pipes with threaded ends, a retrievable shoe in the bottom pipe, and a setting head connected with the top pipe with righthand thread. The new procedure was successfully used to isolate the Kynovskian shales when sidetracking a lateral in Well No. 831 in the Romashkinskoye field. The job was done for forty-eight hours. No problems were encountered while further drilling and casing.