INJEKTIONSVORRICHTUNG UND -VERFAHREN

An injection apparatus for injecting a chemical additive into a fluid mixture flowing into an annulus AN of a well-bore WB comprises a body 1 defining an internal chamber 20 receiving a valve arrangement 30. The body 1 comprises at least one port 14, 18 for coupling to a reservoir RS containing the chemical additive, and at least one injection nozzle 11 for injecting the chemical additive into the fluid mixture flowing into the annulus AN. The valve arrangement 30 has a closed position and an open position defined as a function of the fluid flow-rate of the fluid mixture flowing through the valve arrangement 30. In a closed position, the valve arrangement 30 closes the communication between the reservoir RS and the injection nozzle 11, the injection apparatus delivering a non-activated fluid mixture. In an open position, the valve arrangement 30 puts in communication the reservoir RS with the injection nozzle 11, the injection apparatus injecting the chemical additive into the fluid mixture flowing into the annulus AN.