PRESERVATIVE SUB Russian patent published in 2010 - IPC E21B7/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil-and-gas industry and it is provided for prevention of streamlined long-measuring pipe of caltubing installations from action of maximal rotating moment at operation with helical downhole motor. Preservative sub contains casing and trunk, connected through adapter connector with downhole motor. Additionally casing and bore are connected to each other by torque rods. On external surface of casing and bore are implemented, correspondingly, teeth and fashioned grooving, interacting to each other after cutting of mentioned rods at axial shift of bore.

EFFECT: effectiveness increase of operation ensured by providing of ability of secondary connection at keeping of connection airtightness and providing of enough durability to different loads.

2 dwg