METHOD FOR CEMENTING A LINER IN A WELL AND A DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2022 - IPC E21B33/14 

FIELD: oil and gas industry.

SUBSTANCE: inventions group relates to a method and device for cementing a liner in a well. Method for cementing a liner in a well includes connecting the lower part of the casing of the cementing device with a liner with a release device through the upper part of the casing of the device for cementing the liner to the lower end of the pipe string, lowering the liner into the well to a predetermined depth, pumping the calculated volume of cement slurry into the pipe string, start-up from the wellhead after the last portion of the cement slurry of the squeezing plug and squeezing it with squeezing fluid until it is fixed in the seat of the core of the conical sleeve block, creating excess pressure with further shearing of the screws and moving the suspended cementing plug in the assembly with the block of conical sleeves under the action of increased pressure down to the stop ring and receive a signal about the completion of the cementing process, flushing excess cement slurry with flushing fluid and disconnecting the transport pipe string. The uncoupling device is made in the form of at least two shear elements, above and below the shear elements at an equal distance from them, radial grooves are made, which are equipped with sealing cuffs. The upper part of the housing is connected to the lower part of the housing with the possibility of their synchronous rotation due to the interaction of the outer protrusions of the upper part of the housing with the grooves made at the end of the lower part of the housing. The suspended cementing plug is installed in the annular narrowing of the upper part of the body and fixed relative to the upper part of the body using shear screws, after they are cut, the suspended cementing plug is moved down under pressure until it fits into the stop ring installed in the lower part of the liner, for which the inner diameter of the surface the lower part of the body in contact with the suspended cementing plug is chosen equal to the inner diameter of the liner being lowered into the well.

EFFECT: increasing the efficiency of liner cementing by improving the quality of the cement lining, combining the operations of cementing and liner rotation, guaranteed disconnection of the pipe string from the liner regardless of its length and in any interval of the well with any complexity and direction of the wellbore.

2 cl, 4 dwg