RUPTURING COUPLING AND POSITIVE INDICATION OF COUPLING OPENING FOR HYDRAULIC FRACTURING Russian patent published in 2017 - IPC E21B34/06 E21B43/26 

FIELD: mining.

SUBSTANCE: group of inventions relates to multi-staged hydraulic fracturing of multiple zone formation, which must be successively isolated for treatment. For this purpose there is downhole tool and method of its opening. Downhole tool includes housing with inner hole and at least one outlet hole, communicating inner hole with housing external part. There is insert, placed in inner hole and made with possibility to move under action of first pressure level, applied to insert opening plug dropped to well. Insert is made with possibility to displace at least from closed position into open position relative to said at least one outlet hole and obtaining first reaction to pressure, indicating insert opening. There is rupturing belt, arranged with seal on housing external part at location of said at least one outlet hole. Rupturing belt is provided with possibility of fracturing under action of applied pressure second level, transmitted through said at least one outlet hole to rupturing belt, when insert is in open position. There is possibility of obtaining second response to pressure, indicating reliable opening of at least one outlet hole.

EFFECT: technical result is increase in downhole tool operation reliability and method higher efficiency.

20 cl, 20 dwg