METHOD FOR ISOLATING INFLOW OF BOTTOM WATER IN OIL WELLS Russian patent published in 2017 - IPC E21B33/13 E21B43/32 E21B43/11 

FIELD: oil and gas industry.

SUBSTANCE: method includes stopping a well, in which the level of water-oil contact overlapps lower openings of a perforation interval. A downhole equipment is extracted from production column of a main shaft. A plug packer is set to 1 m below the water-oil contact. A grouting composition, for example, based on grouting portland cementportland cement - PCT-100 is injected into the lower interval of the perforation holes followed by formation of water-insulating screen. An assembly with a cutter is lowered into the well. The plug packer is drilled. The assembly with the cutter is lifted out of the well, and a guide assembly with a through channel and an outlet hole equipped with anchor-packer device is lowered on the drill pipe string. The drill pipe string is extracted leaving the guide assembly in the production column. A hydromonitor nozzle is lowered on the flexible pipe (FP) into the guide addembly to the outlet hole of the guide assembly through hole. The jets of sand-liquid mixture (SLM) cut a hole in the wall of the production column. After the hole is cut in the wall of the production column, the SLM is replaced with hydrocarbon-based solution (RBS). The RBO jets flush at high pressure the cement stone behind the production column, and the hydromonitoring nozzle subsequently moves in the radial direction to flush the water-insulating screen and rock of the productive formation to form an elongated radial branch. Upon formation of the first radial branch, the FP with a high-pressure hose and the hydromonitoring nozzle is extracted from the well. The guide assembly is turned in the same plane by 45 degrees and similar operations to form the next radial branch are carried out. Next, similar operations to form the next radial branchs are carried out after turning the guide assembly by the next 45 degrees. After drilling the radial channels in one plane of the productive formation, the radial channels are drilled below this plane, but in the thickness of the existing water-insulating screen. After formaton of all planned radial branches, a water-insulating composition (WIC) is pumped therethrough to create a water-insulating screen along the radius and provide a spatial and long-term barrier on OWC movement path and leaving a cement cup in the well cavity no higher than the water-insulating screen.

EFFECT: increase of efficiency of water-proofing works in oil wells, formation of extended and thick water-insulating screen.

7 dwg, 2 tbl