METHOD FOR INITIATING INFLOW FROM FORMATION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2012 - IPC E21B43/25 

FIELD: mining.

SUBSTANCE: method includes descending the cylinder into the hole by string, the cylinder has radial holes covered by valve unit due to connection to string in transport position, packer and circulation valve mounted before the packer for connection to the tubular annulus, sealing of tubular annulus by packer above the formation, decreasing fluid level in tubing string and tubular annulus for creation of differential pressure drawdown, opening valve unit. Level reduction in tubing string and tubular annulus is done via pumping of gassy fluid through flexible pipe preliminary descended into string till the interaction with circulation valve that is opened in transport position for connection to tubing string and tubular annulus. Valve unit capable of fluid inflow from formation with string in transport position is opened after creating differential pressure drawdown and circulation valve is closed. After that the formation undergoes acid treatment with the following process holding. Then flexible pipe is descended into the string, gassy fluid is pumped into the string to decrease the fluid level in it and create differential pressure drawdown with carrying out the product of acid reaction with formation solid. The device includes packer connected to the string, wellhead fittings with branches hydraulically connected to the tubing string and tubular annulus of string, cylinder with radial holes mounted under the packer, the holes are covered in transport position, valve unit performed in a form of piston fixed in the cylinder in upper position and circulation valve located above the packer performed in a form of sleeve with lower end stop and side holes capable of closing by hollow bush fixed in upper position by shear elements. The device is equipped with flexible pipe descended into tubing and capable of interacting with hollow bush after creation of differential pressure drawdown for its movement till the end stop with closing the side holes open in transport position. Radial holes of the cylinder are closed in transport position by piston fixed in the upper position by decomposable elements and capable of opening the radial channels at movement downwards. The piston is additionally equipped with valve passing the fluid upwards.

EFFECT: simplification of inventions and adjustment of differential pressure drawdown value in the course of well development.

2 cl, 4 dwg