Well tool device for opening and closing a fluid bore in a well

1. A well tool device comprising:

a housing having an axial through bore;

a sleeve section releasably connected to the housing in the axial through bore, wherein the sleeve section comprises an axial bore;

a frangible disc provided in the axial bore of the sleeve section in sealing engagement with the sleeve section; and

a first supporting sleeve fixed to the housing in the axial through bore and a second supporting sleeve provided radially inside of, and releasably connected to, the first supporting sleeve,

wherein the sleeve section is axially displaceable within the axial through bore between a first position and a second position;

wherein the housing comprises an axial bypass fluid passage provided axially between a first location above the sleeve section and a second location below the sleeve section when the sleeve section is in the first position, wherein the axial bypass fluid passage is provided radially between the sleeve section and the housing when the sleeve section is in the first position;

wherein the well tool device comprises a sealing device provided radially between the sleeve section and the housing when the sleeve section is in the second position; and

wherein the first supporting sleeve comprises an upwardly facing surface configured to support a lower end of the sleeve section when the sleeve section is in the second position.

2. The well tool device according to claim 1 , wherein the axial bypass fluid passage is provided as a widened section in a radial direction of the axial through bore, wherein a height of the widened section of the axial through bore is higher than a height of the sleeve section.

3. The well tool device according to claim 2 , wherein the axial bypass fluid passage is provided as a plurality of axial bypass fluid passages separated by axial sleeve guides.

4. The well tool device according to claim 2 , wherein the well tool device comprises a pre-compressed locking ring provided in a recess in an outer surface of the sleeve section, and wherein the locking ring is configured to be engaged in a recess in the axial through bore in the second position.

5. The well tool device according to claim 1 , wherein the axial bypass fluid passage is provided as a plurality of axial bypass fluid passages separated by axial sleeve guides.

6. The well tool device according to claim 5 , wherein the well tool device comprises a pre-compressed locking ring provided in a recess in an outer surface of the sleeve section, and wherein the locking ring is configured to be engaged in a recess in the axial through bore in the second position.

7. The well tool device according to claim 1 , wherein the well tool device comprises a pre-compressed locking ring provided in a recess in an outer surface of the sleeve section, and wherein the locking ring is configured to be engaged in a recess in the axial through bore in the second position.

8. The well tool device according to claim 1 , wherein the second supporting sleeve comprises an upwardly facing surface configured to support the frangible disc when the sleeve section is in the second position.

9. The well tool device according to claim 8 , where the well tool device comprises a disintegration device fixed to the housing; wherein the frangible disc is configured to be displaced downwardly into contact with the disintegration device when the second supporting sleeve is released from the first supporting sleeve.

10. The well tool device according to claim 1 , where the well tool device comprises a disintegration device fixed to the housing; wherein the frangible disc is configured to be displaced downwardly into contact with the disintegration device when the second supporting sleeve is released from the first supporting sleeve.