METHOD FOR ADJUSTABLE LIQUID INJECTION IN PRODUCTION FORMATION Russian patent published in 2017 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: method includes exploring formation properties, constructing an injection well that opens up different horizons with different properties, equipping well tubing with a packer separating the open horizons, and adjusting the pumping equipment when injecting liquid into the required horizon. Investigation of the formation is carried out to determine watered sections of the formation or cuts of aquifers and the level of water-oil contact if they are present in the oil-bearing part of the formation. Additionally, the studies are carried out to determine presence of oil-bearing areas or oil-bearing cuts, as well as to define the difference of permeability of the formations. A branched well with horizontal sections is used as an injection well, among which an aquifier area or formation cut is opened first, and then above the bottom of the formation oil-bearing area or directly above the water-oil contact if present. The distance between the watered area or the watered cut to the oil-bearing area or the oil-bearing cut is allowed 700 m at most. The packer with the well tubing cuts off the first horizontal section above the aquifer or the formation cut, from where the water is pumped to the well above the hydrodynamic level of the formation oil-bearing area for natural overflow and to maintain the formation pressure in this area. The amount of pumped liquid is adjusted by the pumping equipment capacity.

EFFECT: increasing method efficiency by using watered areas or formation cuts for pumping large volumes of liquid, creating a uniform front of displacement by small-capacity pumps.

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