Development and Field Test of Non-Lining Inflatable Packers

In order to solve the problem of residual deformation and potential pipe sticking created by steel wire screen or steel skeleton packer after its setting with pressure-bearing,an non-lining inflatable packer was developed with springs embedded in both ends to support the rubber by designing the non-lining inflatable packer rubber to improve the re-setting reliability.The packer rubber can be fully expanded and sealed under differential pressure difference of 2.5-5.0 MPa.Indoor tests showed that the newly developed packer could be set and reset for 50 times with bi-directional pressure-bearing capacity of 85 MPa at working temperature of 150℃,and the packer rubber has residual deformation less than 1.5% after releasing.Field tests have been conducted in refracturing of old wells in the Yanchang Oilfield.The packer is very easy to set,and smoothly releases after setting in the well more than 50 hours,with OD expanded from 108 mm to 109 mm only.Research results showed that the innovative inflatable packers have outstanding sealing capacities and can be reset and released repeatedly,with less deformation of rubber than that of conventional packers,easily pulling the pipe string out of the hole.