PLUG PACKER Russian patent published in 2010 - IPC E21B33/12 

FIELD: oil and gas production.

SUBSTANCE: plug packer comprises a trunk with an internal cylindrical sample, an end cap and an upper seat; besides it accommodates a packing element, an indexing mechanism for the packing element interacting with notches on the trunk, base and complementary cones whereto base and complementary oval sockets respectively are connected, a plug-in assembly, restraining balls mounted in the holes of the trunk and interacting with the plug-in assembly on the inside, and with a hollow insert - on the outside that is jointed with the complementary cone at the bottom, and a stop ring. The complementary cone is longitudinally divided in sectors for the complementary oval sockets; it is radially movable inside and jointed with the hollow insert which is tightly and rigidly connected at the bottom with the end cap. The base cone has a cylindrical sample on the inside at the bottom, while its seat is designed as a bulge of the trunk which interacts on the inside with the sectors of the complementary cone in the run-in position and is arranged above the complementary cone when removing the packer after constrained movement of the plug-in assembly upwards relatively to the trunk for releasing the balls.

EFFECT: design simplicity and eliminated jamming while removing.