DEVICE USED FOR LOWERING, SUSPENDING AND CEMENTING CASING STRING SECTIONS Russian patent published in 2009 - IPC E21B33/14 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to devices used for lowering, suspending and cementing casing string sections, and can be used when fixing oil and gas wells. Device consists of a suspension frame with stepped internal and external surfaces, a supporting pipe, a nut with left-handed thread along external surface for the purpose of communicating with the suspension frame, and splines on internal surface for the purpose of communicating with supporting pipe splines; at that, supporting pipe is equipped with washout holes, and inside supporting pipe located is a bush equipped with a seat meant for a discarded ball-bomb, and outside the pipe there located is a thrust bush meant for fixing a bearing. End of the supporting pipe is stepped, at that outer diameter of the middle step is equal to inner diameter of the suspension frame, outer diameter of top step is equal to inner diameter of the nut, and outer diameter of bottom step equals to inner diameter of the bearing. The latter is made as a support one, and bottom step of the supporting pipe is installed with the possibility of unloading with an end surface to support bearing, and is connected to the suspension plug frame with the possibility of rotating relative to each other, and disconnecting. Bottom step of the supporting pipe is made with through holes meant for pins. External surface of the suspension plug frame is made with an annular groove, which is meant for arranging ends of pins. External surface of the suspension frame is provided with longitudinal grooves which are located radially, and meant for washing fluid passage. Upper edge surface of the nut is cone-shaped.

EFFECT: improving operating reliability owing to secure disconnection from lower section of the casing string, and simplifying the design of the device intended for lowering, suspending and cementing the casing string sections.

5 cl, 8 dwg