WELL CONSTRUCTION FINISHING METHOD Russian patent published in 2014 - IPC E21B43/10 

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of a well shaft in a productive formation and a sump at its bottom; reaming of the shaft at the productive formation interval without well flushing with removal of drilled rock slurry to the sump; partial filling of the shaft with filtering mass after it is reamed; lowering to the well of the tubing string of the liner with slot perforation channels; performance of hydraulic fracturing of the productive formation and stimulation of the formation fluid flow to the well. According to the invention, well shaft and sump drilling is performed from under the shoe of the casing string. Prior to lowering to the well, a mechanical anchor and a plug are connected to the lower end of the liner, and an elastic self-sealing cuff with a removable casing arranged on its outer side is connected to the upper end. Lower part of the tubing string is equipped with a packer and a delivery branch pipe, the lower end of which is plugged. The delivery branch pipe is connected to the removable casing. Before hydraulic fracturing of the productive formation is performed, the mechanical anchor is fixed in the sump, and the packer is installed in the casing string. Partial filling of the shaft with filtering mass is performed when fracturing fluid with proppant material is being pumped to the productive formation. After the pumping process is finished, there subsequently performed is breakdown of the packer in the casing string, axial movement of the tubing string in the upward direction to release the elastic self-sealing cuff from the removable casing and further removal to surface.

EFFECT: simpler and improved effectiveness of the well construction finishing method.

5 cl, 8 dwg