METHOD FOR SECONDARY PENETRATION OF A LAYER Russian patent published in 2021 - IPC E21B43/117 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, namely, to methods for secondary penetration of a borehole. The method includes preliminary creation of perforations in the borehole wall and the annulus cement ring and subsequent deepening of the perforation channels in the layer. Prior to preliminary penetration, an anchor equipped with a guiding head on top is installed in the borehole below the layer penetration interval. Preliminary creation of perforations is executed with a cumulative perforator, prior to lowering equipped with an orientation coupling configured to interact and be guided, when being lowered into the borehole, with the guiding head of the anchor, and preliminary shaped charges providing large holes and installed in pairs along the height of the perforator. The paired shaped charges are spaced by 180±5° along the perimeter of the perforator. After preliminary creation of holes in the borehole wall, the perforator is removed and the preliminary spent charges are replaced with deepening shaped charges ensuring deep penetration into the layer. The perforator is lowered until interaction of the guiding anchor head and perforator coupling in order to guide the perforator along the height and perimeter of the borehole and align the preliminary perforations with the deepening shaped charges.

EFFECT: time for penetration of the borehole walls is reduced.

1 cl, 1 dwg