MULTISTAGE STIMULATION DEVICE, SYSTEMS AND METHODS Russian patent published in 2020 - IPC E21B34/14 E21B43/08 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to multi-stage stimulation of wells in one round-trip operation. Multi-stage well completion system comprises completion column, having at least a first lower downhole stage and a second located up the barrel with a gap relative to the first one. Each stage has a tubular body, stimulation holes in the body fluidly connected to the completion column channel and annular space. Lower spool bush is made with the possibility of axial displacement in the body, its actuation by the first object pumped downwards along the completion column for opening of stimulating holes in the body. Upper spool bushing located higher along borehole relative to lower, made with possibility of axial displacement in housing, actuation by second object, larger by value of increment, pumped downwards on completion column to close stimulation holes. Lower spool bushing of each step comprises detachable first seat made on it, made with possibility of further detachment of first object from it. Upper spool bushing of each step comprises second seat made on it with size, suitable for receiving and interacting with object of the same size as detachable seat on lower spool bushing located above the well shaft stage. Upper spool bushing located downstream the well shaft is configured to close the stimulation openings located lower down the wellbore of the stage when the first object hits the second seat of the upper spool bushing, located downstream of the well shaft after disconnection of the first object from the lower spool bushing located higher along the well bore of the stage. Disclosed is a method for multi-stage stimulation of well.

EFFECT: technical result is providing enabling the possibility of closing the stimulation holes located lower along the well bore with the help of the object opening the holes higher along the well bore.

19 cl, 10 dwg