FIELD: oil industry; oil and oil products transportation pipe lines; emptying pipe lines in case of repair, pressure tests and removal of oil products pipe lines from operation. SUBSTANCE: oil products pipe line is shut off by means of helium separating plug which consists of three parts: head part, central part and tail part. Length of plug is equal to 0.001-0.002 of length of oil products pipe line to be emptied. Volumes of head, central and tail parts are related as 20:70:10 percent. After plug has been formed in pipe, it is forced by water at simultaneous filling of pipe. Amount of water is determined on the basis of velocity of plug of about 0.5 m/s. Head and tail parts are made from known composite materials at effective viscosity no less than 10,000 poises. Central part is made from composite material which is just fluid viscoelastic gel on base of water-soluble polymer possessing considerable reversible deformation. EFFECT: enhanced efficiency. 2 cl
