DEVICE BY AYGUNYAN FOR TAMPING OF CASING STRING Russian patent published in 2015 - IPC E21B33/14 

FIELD: oil and gas industry.

SUBSTANCE: device comprises a bearing element, a bushing rigidly connected to the bearing element and arranged under it, the first elastic locking element placed in the bushing, a cementing head placed on the wellhead on the first casing string, and the second elastic locking element placed in the cementing head. The bearing element is made in the form of a stop ring with an axial through channel. In the lower part of the bearing element there is a lower plug catching baffle, in the upper part - an upper plug catching baffle. The bushing is made with radial holes. The first elastic locking element is made as capable of regulating the tamping solution flow during tamping of the casing string and prevention of the backflow of this solution into the casing string upon completion of the casing string tamping. The cementing head is made with an axial through channel and has a stop device. The second elastic locking element has density below density of the tamping solution and is made as capable of movement from the cementing head along the entire casing string to the upper plug catching baffle of the bearing element and fixation of the "stop" moment.

EFFECT: increased reliability of operation, provision of tightness of the device, prevention of a cement sleeve in the casing string and shoe exposure, reduced labour inputs, saving of funds.

18 cl, 2 dwg