METHOD FOR ISOLATION OF WATERED INTERVALS IN HORIZONTAL SECTION OF WELLBORE Russian patent published in 2017 - IPC E21B33/13 E21B33/12 E21B43/10 E21B47/00 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil industry, particularly to methods of separation of water-bearing and oil-bearing intervals of the horizontal wellbore. The method implementation includes lowering with washing into the drilled uncased by production string the horizontal part of the wellbore at least one well screen comprising a tail-pipe equipped with shearable plugs. Then the well space between the tail-pipe and the well walls are sealed with a packer or packers. Then the plugs inside the tail-pipe are crushed by a special tool, the tail-pipe is detached from the transport string which is recovered to the surface. The well is explored, the subsurface equipment is lowered and the well is put into operation. The packer to be used is water swellable or oil swellable or water and oil swellable. Before lowering the tail-pipe the filters are additionally equipped with a lower packer, the open wellbore is surveyed for presence and identification of water inflow intervals, open hole calibration with gauging and the section of open hole without cavities in the well walls are identified from both sides of the water inflow intervals. In view of these surveys the tail-pipe is assembled and tripped. Filters are arranged out of water inflow intervals. The packers are arranged in certain sections of the open hole, namely, from both sides of water inflows intervals. Upper packer is arranged in the cased part of the wellbore. Then the well fluid replacement is performed in the wellbore by the fluid which provides the most rapid swelling of the packers. After the process holding, sufficient for swelling of packers, the space between the production and transport strings is compressed by fluid injection, providing the most rapid swelling of packers. In case of leaks the drilling fluid in the borehole is replaced by the fluid providing the fastest swelling of packers, process holding and pressure test until making sure in complete absence of circulation in the wellbore or injectivity in the annulus. If there is a water inflow from the downhole the tail-pipe bottom is equipped with the valve, fluid permeable in the direction from the tail-pipe to the hole.

EFFECT: invention is featured by improved efficiency of insulation of watered intervals of openhole of horizontal wells due to objective monitoring of installation and activation (sitting) of packers.

2 cl, 8 dwg