OPEN DEVELOPMENT METHOD OF MINERAL RESOURCES DEPOSITS Russian patent published in 2012 - IPC E21C41/26 

FIELD: mining.

SUBSTANCE: first, regular hexagons with the sides equal to diameter of the main wells are marked on plane of extraction field. Then, external and central circles with diameter equal to diameter of extraction wells are marked at tops and in the centre respectively of the above hexagons. Besides, each boundary circle of one hexagon adjoins three circles of two neighbouring hexagons as per close packing scheme. After that, core of central well is drilled in the centre of hexagon by means of core method with pre-drilling of service well. System of cracks directed perpendicular to axis of wells is made out of the cavity of the above well at the depth of core drilling of external wells, or slot raise with diameter equal at least to 2.4 of the extraction well diameter is cut. After that, cores of the rest six extraction wells with the centre at tops of hexagons are drilled and lifted. Therefore, core drilling cycle of six of seven wells excludes technologically complex and time-consuming operation of core removal from rock mass.

EFFECT: improvement of drilling capacity of core of large diameter due to their preliminary cutting prior to the beginning of the well drilling.

3 cl, 6 dwg