METHOD FOR FIXING A LINER IN A WELL WITH SUBSEQUENT HYDRAULIC FRACTURING AND A DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2022 - IPC E21B33/14 

FIELD: wells.

SUBSTANCE: inventions group relates to methods and devices for fixing a liner in a well for subsequent hydraulic fracturing through the liner. The method includes connecting the lower part of the device body with a liner with a release device through the upper part of the device body 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, launching from the wellhead after the last portion of the cement slurry of the squeezing plug and squeezing it with the squeezing liquid until it is fixed in the seat of the conical collar block, creating excess pressure with further shearing of the screws and moving the suspended cementing plug in the assembly with a block of conical collars under the action of increased pressure down to the stop ring and receiving 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 with sealing cuffs are made. The suspended cementing plug is installed in the annular narrowing of the mounting sleeve of the upper part of the body and fixed relative to the mounting sleeve 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 of the lower part of the body in contact with the block of conical collars of the suspended cementing plug is chosen equal to the inner diameter of the liner lowered into the well. At the end of the upper part of the housing, counter slots are made, and at the end of the lower part - grooves with the possibility of their combination. At the end of the lower part of the housing, a conical groove is made from the inside. After disconnecting the transport string of pipes, the well is left to wait for the cement to harden and the liner is perforated, then a sealing assembly with a cone end, equipped with annular sealing cuffs, is lowered into the well, with the possibility of being aligned with the cone groove of the lower part of the body, hydraulic fracturing is carried out.

EFFECT: creating a reliable, low-modulus and easy-to-use design that ensures the delivery of the liner to the well, increasing the efficiency of liner clamping by improving the quality of the cement lining, combining the operations of clamping and rotating the liner, 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, as well as the creation of a tight joint between the liner and the working string for guaranteed and high-quality hydraulic fracturing through the liner.

2 cl, 6 dwg