METHOD AND DEVICE FOR CUMULATIVE OIL WELL PERFORATION (VARIANTS) Russian patent published in 2006 - IPC E21B43/117 

FIELD: oil industry, particularly methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells.

SUBSTANCE: device comprises instrument head, triggering mechanism, cased cumulative perforator provided with mechanical or adiabatic detonator without primers, and charges having penetration capability up to 700 mm and inlet hole diameter of 8-26 mm, one or two depression chambers with valves for chamber opening. Valves have diameters of 10-65 mm. Electrohydraulic triggering mechanism is used as the triggering mechanism. After triggering mechanism opening upper receiving valve and lower valve, namely depression chamber striker, may be opened to provide depression chamber opening and depression creation in well along with simultaneous cumulative perforator fuse initiation to create perforation channels during reduced formation pressure period and with forming repression hydroblow action to provide hydraulic fracturing of formation with following depression-repression perforated interval treatment. When two depression chambers are used the second chamber is chamber having automatic time-delay valve. Device in accordance with the second embodiment is not provided with depression chambers. Method involves installing device in design perforation interval; actuating explosion charges and creating perforation channels. In accordance with the first embodiment time-controlled and value-controlled depression is created to provide repression hydraulic formation fracturing along with single-stage or double-stage high-cycle hydroblow action by using device having one or two depression chambers. In accordance with the second embodiment device without depression chambers is used.

EFFECT: increased efficiency of secondary productive formation penetration.

5 cl, 6 dwg