MULTIPLE HYDRAULIC FRACTURING OF FORMATION IN WELL HORIZONTAL SHAFT Russian patent published in 2014 - IPC E21B43/267 

FIELD: mining.

SUBSTANCE: proposed method comprises formation of fractures in different intervals of productive bed exposed by the well horizontal shaft by lowering the packer on pipe string. Packer is fitted in the well to feed hydraulic fracturing fluid in the filter mounted at every part of horizontal shaft corresponding to every said interval. Other parts are isolated to make fractures to be lined by forcing carrier fluid with proppant therein. Interval hydraulic fracturing is performed in direction from the face to head by pipe string lowering. Pipe string represents a string of flexible pipes with drillable packer at the end. Drillable packer seating is performed ahead of every section of the well horizontal shaft filter, fractures are produced and lined by forcing carrier fluid with proppant therein. To fix proppant in well zone, fixing solution is forced in pipe string at the rate of 0.5 m³ per 1 metre of filter length and into said zone in one and a half volume of pipe string. Thereafter, wellhead is sealed by wellhead gland. Well tubular space is lined out with hydraulic accumulator. Then, without decreasing hydraulic pressure in pipe string, it is lifted by 1 metre. Hydraulic accumulator takes up hydraulic pressure surge in well annulus while drillable packer tightly shuts off the filter section whereat hydraulic fracturing occurs. The, pipe string is withdrawn from the well to make interval hydraulic fracturing in other filter sections of the well horizontal shafts. At termination of hydraulic fracturing, pipe string at wellhead if equipped with drillable toll and jet head. Pipe string is lowered in the well to remove packers by drilling-out from wellhead to face. Then, drillable tool is cut out to force fluid in pipe string along with its rotation and displacement from face to head to jet processing of inner surface of filters via jet head.

EFFECT: higher efficiency and reliability, accelerated tripping processes.

3 dwg