Patent ID: 9683425
Date: 2017-06-20
CPC Classifications: E21B

Claim:
1. A downhole injection tool for injecting an injection fluid into an annular space surrounding the downhole injection tool, enclosed by an inside wall of a borehole or a well tubular structure, the downhole injection tool comprising: an injection unit comprising a first expandable cup adapted to provide a first seal against the inside wall, a second expandable cup adapted to provide a second seal against the inside wall, the two cups, in an expanded state, together defining an isolated zone of the annular space, at least one pipe element extending in a longitudinal direction between the two cups, the pipe element providing a fluid passage between an inlet arranged in one end of the pipe element and an outlet arranged in the pipe element between the cups, the second expandable cup being slidably connected with the pipe element and displaced in the longitudinal direction from an initial axial position to a displaced axial position away from the first expandable cup under the influence of the injection fluid injected into the isolated zone, whereby a distance d between the two cups is increased, wherein the injection unit further comprises a retainer sleeve being slidably arranged around the expandable cups to prevent unintentional expansion of the expandable cups during insertion of the downhole injection tool, and wherein the retainer sleeve is slidable in the longitudinal direction and the expandable cups are released by movement of the retainer sleeve in the longitudinal direction, wherein the first and second expandable cups are maintained in a radially compressed position within the retainer sleeve during insertion of the downhole injection tool and the cups are deployed to expand to radially expanded positions in sealing contact with the inside wall when the retainer sleeve is moved, and wherein the second expandable cup is configured to maintain sealing contact with the inside wall as the second expandable cup slides from the initial axial position to the displaced axial position.