METHOD FOR SHUT OFF OF WATERED INTERVALS OF PRODUCTIVE FORMATIONS IN HORIZONTAL WELLS AT FIELDS WITH LOW-PERMEABLE RESERVOIRS Russian patent published in 2018 - IPC E21B33/138 E21B43/22 E21B43/32 E21B47/10 C09K8/504 E21B28/00 E21B43/25 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and can be used to shut off watered intervals in a productive formation in horizontal wells at fields with low-permeability reservoirs. This method includes treating the watered formation interval with physical action by means of an apparatus for generating elastic pulses in the hydrosphere of a horizontal well and subsequent injection into the formation of the gelling waterproofing composition containing 1.0–5.0 % by weight of sodium silicate and 0.5–1.5 % by weight of chromium acetate, 0.1–0.5 non-ionic surfactant and the rest is water. Said composition is extruded into the formation and a technological pause. At the same time, this device is equipped with an apparent resistance module to detect watered intervals in the horizontal open wellbore and a light absorption coefficient module to detect watered intervals in the horizontal wellbore. Water entry intervals are allocated. Then, injection of a temporarily blocking composition that does not filter into the formation is carried out. Wherein when the device is lifted, each interval is processed by physical action, taking into account the filtration-capacitive properties. In this case, before pumping the waterproofing composition, a fresh water rim is poured into the wells, containing 0.01–0.05 % by weight of the tetrasodium salt of ethylenediaminotetraacetic acid. Further, the induction period of the waterproofing composition at the formation temperature is set to 4–8 hours, and the technological pause is 20–30 hours, after which the well is put into operation.

EFFECT: increasing the efficiency of oil displacement from the reservoir and reducing the production of associated produced water by cutting off high-watered intervals in the horizontal part of production wells.

1 cl, 1 tbl, 1 ex