METHOD OF WELL PERFORATION BY DOUBLE HYPERCUMULATIVE CHARGES Russian patent published in 2015 - IPC E21B43/117 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, in particular to methods of production deposits opening in oil wells. Method of well perforation means co-axial installation in common tight enclosure of two spaced-apart cumulative charges, initiating of the explosive charges with recesses at the charge end, located at opposite side of the charge recess, recesses lining using metal enclosures. The charge installed further or closer to the obstacle is initiated first with time delay varying from 0 to time equal to at least time of formation of the first cumulative jet in the cumulative charge. The second cumulative charge is initiates by formation of two cumulative jets moving coaxially one after another along the charge central line and ensuring in series the obstacle penetration. During throwing and compression of the cumulative enclosure it is under additional action due forced interaction of the cumulative enclosure with one or several additional bodies, their collision, and sliding of parts of the cumulative enclosure material relatively to the additional body with simultaneous rotation of parts of the cumulative enclosure material by angle of convergence to the central line of charge over 180 degrees, and does not exceeding 360 degrees, collision of parts of the cumulative enclosure material on the central line of the charge at angle over 180 degrees and not exceeding 360 degrees. The first initiated charge creates the cumulative jet with maximum speed gradient and speed gradient of the head part of the cumulative jet ensuring crater with shape close to cylindrical shape, and crater diameter in the obstacle exceeding the maximum diameter of the second created cumulative jet. The second initiated charge creates the cumulative jet moving with maximum speed of the head part not exceeding the minimum speed of tail of the first cumulative jet, and with minimum speed at least equal to critical speed for the given materials of the jet and obstacle.

EFFECT: increased efficiency of secondary opening of the production deposits.

3 dwg