Device for a long well tool

1. A device for a tool string for insertion in a well, comprising:

a brake nose arranged at a leading tip of the tool string; and

a tool nose connected to the brake nose axially in a one-way releasable manner,

wherein a landing sleeve configured to receive the brake nose is connected in a locking manner to a well tubing.

2. A device according to claim 1 , wherein the landing sleeve is positioned immediately above a safety valve of the well.

3. A device according to claim 2 , wherein the landing sleeve includes a brake tubing.

4. A device according to claim 3 , wherein a through-going pipe opening of the landing sleeve and/or the brake tubing comprises an upper bore and a lower bore, and wherein the diameter of the lower bore differs from the diameter of the upper bore.

5. A device according to claim 4 , wherein the brake nose is provided with a brake spindle configured to be moved into the upper and lower bores.

6. A device according to claim 5 , wherein the brake spindle is externally provided with a first labyrinth and a second labyrinth, and wherein the labyrinths together with the corresponding bores constitute labyrinth seals for a confined annular space between the brake spindle and the brake tubing.

7. A device according to claim 4 , wherein the diameter of the lower bore is smaller than the diameter of the upper bore.

8. A device according to claim 3 , wherein the brake nose is configured to be locked to the brake tubing by means of a releasable bayonet connector.

9. A device according to claim 1 , wherein the tool nose is secured in the brake nose by a tool lock.

10. A device according to claim 9 , wherein release of the tool lock is blocked by means of an axially movable locking slide.

11. A device according to claim 9 , wherein the tool lock is connected to a piston in a one-way moveable manner.

12. A device according to claim 1 , wherein the brake nose and the leading tip are arranged along a common axis.

13. A braking device for limiting a velocity of a tool string, comprising:

a cylindrical housing connected to the tool string; and

a brake spindle comprising first and second braking sections,

wherein the first braking section comprises a first labyrinth, and the second braking section comprises a second labyrinth, and

wherein the second labyrinth has a larger diameter than the first labyrinth.

14. A braking device according to claim 13 , wherein:

the second labyrinth is closer to the tool string than the first labyrinth.

15. A braking device according to claim 13 , wherein:

the brake spindle is surrounded by a latch ring; and

the latch ring protrudes into an annulus at a leading end of the cylindrical housing.

16. A braking device according to claim 15 , wherein:

the latch ring is provided with a protruding flange; and

first and second spiral-shaped springs extend from the flange.

17. A braking device according to claim 13 , wherein the first and second braking sections are separated by a non-braking section.

18. A braking device for use with a tool string, comprising:

a cylindrical housing connected to the tool string; and

a brake spindle comprising a plurality of labyrinths configured to reduce a velocity of the tool string,

wherein diameters of the labyrinths are different.

19. A braking device according to claim 18 , wherein:

the labyrinths define at least one annular space where fluid at an increased pressure can be confined.

20. A braking device according to claim 18 , wherein:

the cylindrical housing comprises a choke ring configured to form a turbulent flow upon falling of the tool string.