METHOD OF SECURING A HIDDEN CASING STRING OF A BOREHOLE WITH ROTATION AND CEMENTING OF THE ZONE ABOVE THE PRODUCTIVE FORMATION Russian patent published in 2021 - IPC E21B33/14 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to the field of well construction in the oil and gas industry, in particular to methods for the construction of oil, gas and steam injection wells, namely to methods of securing a secret casing. In particular, a method is proposed for securing a hidden casing of a borehole with rotation and cementing of a zone above the productive formation using cementing and setting devices, which includes the following steps: assembly of a hidden casing; attaching a setting device capable of rotating the wellhead; fixing the secret casing to the installation device nozzle that is not retrievable from the well; running a secret casing into the well until the planned depth is reached on a transportation string connected to the setting tool through a sub; cementing with rotation by pumping cement slurry into the pipe space of the secret casing and then one or more types of pushing fluid using a system of release plugs in the process of forcing, with filling the cementing interval behind the pipe space of the secret casing with cement slurry by means of a cementing device; regular disconnection of the transportation column after pushing the system of plugs to the stop-pipe and a sharp increase in pressure; activating the unit for disconnecting the setting device with the subsequent resumption of the circulation of the liquid and flushing out the excess grouting solution; retrieving the transportation string from the well.

EFFECT: ensuring the improvement of the quality and durability of the cement stone.

2 cl, 7 dwg