METHOD FOR PREVENTING CONING OF BOTTOM WATER IN SMALL-SCALE HORIZONTAL WELL Russian patent published in 2018 - IPC E21B43/32 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and enables to solve the task of preventing the inflow of bottom water in a horizontal section of a small-scale oil producing well. Method for preventing coning of bottom water in a small-scale horizontal well (up to 100 m) comprises the following consecutive stages. First, deepening the main (vertical) wellbore to a depth 1–2 m below the water-oil contact level. Then a casing string is lowered into the drilled interval, the diameter of said string being smaller than the main vertical section of the well. Casing is then cemented and the cement is left to harden. Assembly for radial drilling (radial perforation) is lowered and a radial channel is drilled with a length of no more than 100 m. Further, a waterproofing composition based on micro cement is pumped under pressure into this channel to form a waterproof screen. After that, the injected composition is cemented with cement mortar, leaving a cement cup installed in the drilled (vertical) wellbore. Further, the well is left for the waiting period for the hardening of the cement. Development and commissioning of the well is carried out through the available perforations in the horizontal section. Waterproofing composition used is a composition including R-U microdur, polyfunctional modifier PFM-ISO, superplasticiser F-10 and water with water-cement ratio 1 and with the following component ratio, wt%: microdur R-U 48.75–49.05, polyfunctional modifier PFM-ISO 1.0–1.2, superplasticiser F-10 0.9–1.3, water – the balance.

EFFECT: proposed method prolongs water-free operation of the well.

1 cl, 6 dwg