Lateral well locator and reentry apparatus and method

1. A down-hole assembly for locating a window and reentering a lateral well bore in a main well bore after removal of a whip stock, comprising:

a running tool having an upper section, a middle section and a lower section, said running tool including a window locator for locating said window, said window locator comprising a pivoting arm and a window locating head;

a guide member having an upper section, a middle section and a lower section, said guide member having a wedged-shaped outer surface for diverting a down-hole tool through said window and into said lateral well bore;

wherein said lower section of said running tool and said upper section of said guide member are each shaped to receive the other in mating relationship;

wherein said lower section of said running tool and said upper section of said guide member are capable of being detachably connected, and when detachably connected, said running tool and said guide member are in fluid communication;

wherein said window locating head has a run-in position, a retracted position, and a window locating position and wherein in said window locating position, said window locating head is biased in a direction external to said running tool and a portion of said window locating head is positioned within said window; and

wherein said running tool includes a stop means for preventing retraction of said window locating head from said window locating position to enable determination of an upper edge of said window by pulling upward on said tool and of a lower edge of said window by pushing downward on said tool.

2. The down-hole assembly according to claim 1 , wherein said running tool includes a biasing means operatively associated with said window locator, said biasing means exerting a force on said pivoting arm of said window locator to bias said window locating head in a direction external of said running tool.

3. The down-hole assembly according to claim 1 , wherein in said run-in position, said window locating head is positioned between said retracted and said window locating positions and held stationary.

4. The down-hole assembly according to claim 3 , wherein said running tool includes one or more shear pins affixed to said window locator, said shear pins maintaining said window locating head in said stationary position until sheared.

5. The down-hole assembly according to claim 1 , wherein in said retracted position, said window locating head is positioned substantially within said running tool, said window locating head being held in said retracted position by said main well bore.

6. The down-hole assembly according to claim 1 , wherein said running tool includes a block means for restricting a maximum outward pivoting angle of said window locating head.

7. The down-hole assembly according to claim 6 , wherein said block means includes a shoulder capable of receiving an outer edge surface of said window locating head.

8. The down-hole assembly according to claim 1 , wherein said stop means comprise one or more spring-loaded shear pins, said one or more spring loaded shear pins being actuated by displacement of said window locating head from said retracted position to said window locating position and deactivated by a shearing force, said deactivation resulting in said window locating head returning to said retracted position.

9. The down-hole assembly according to claim 1 , wherein said upper section of said running tool has a first internal fluid passage bore and said lower section of said running tool has a second internal fluid passage bore, said first and second internal fluid passage bores being fluidly connected by a conduit, said conduit by-passing said window locator.

10. The down-hole assembly according to claim 1 , wherein said shape of said lower section of said running tool is convex and said shape of said upper section of said guide member is concave.

11. The down-hole assembly according to claim 1 , wherein said lower section of said running tool and said upper section of said guide member are detachably connected by a shear bolt.

12. The down-hole assembly according to claim 11 , wherein said lower section of said running tool and said upper section of said guide member are further detachably connected by a dovetail joint.

13. The down-hole assembly according to claim 1 , wherein said guide member includes an internal fluid passage bore and said running tool includes a stinger pipe fluidly connected to a second internal fluid passage bore, said stinger pipe being sealingly connected to said internal fluid passage bore of said guide member when said running tool and said guide member are detachably connected.

14. The down-hole assembly according to claim 1 , wherein said guide member includes a retrieval means, said retrieval means providing a point of operative attachment for a fishing tool.

15. A down-hole assembly for locating a window and reentering a lateral well bore in a main cased well bore after removal of a whip stock, comprising:

a diverter sub having an upper end and a lower end, said upper end of said diverter sub being operatively connected to a tubular;

a running tool having an upper section, a middle section and a lower section, said upper section of said running tool being operatively connected to said lower end of said diverter sub, said running tool including a window locator for locating said window, said window locator comprises a pivoting arm and a window locating head, said upper section of said running tool including a first internal fluid passage bore, said lower section of said running tool including a second internal fluid passage bore, said running tool including a conduit fluidly connecting said first and second internal fluid passage bores;

a guide member having an upper section, a middle section and a lower section, said lower section of said running tool and said upper section of said guide member are each shaped to receive the other in mating relationship, said guide member having an internal fluid passage bore, said upper section of said guide member being detachably connected to said lower section of said running tool, said guide member having a wedged-shaped outer surface for diverting a down-hole tool through said window and into said lateral well bore;

a stinger pipe having an upper end and a lower end, said upper end of said stinger pipe being sealingly connected to said second internal fluid passage bore in said lower end of said running tool, said lower end of said stinger pipe being sealingly connected to said internal fluid passage bore of said guide member;

a debris sub having an upper end and a lower end, said upper end of said debris sub being operatively connected to said lower section of said guide member; said debris sub including an internal fluid passage bore in fluid communication with said internal fluid passage bore of said guide member;

an anchor sub having an upper end and a lower end, said upper end of said anchor sub being operatively connected to said lower end of said debris sub, said anchor sub including an internal fluid passage bore fluidly connected to said internal fluid passage bore of said debris sub, said anchor sub including anchor means for detachably affixing said anchor sub to said cased well bore;

wherein said window locating head has a run-in position, a retracted position, and a window locating position;

wherein said running tool includes a stop means for preventing retraction of said window locating head from said window locating position to enable determination of an upper edge of said window by pulling upward on said tool and of a lower edge of said window by pushing downward on said tool.

16. The down-hole assembly according to claim 15 , wherein said tubular is a work string, drill pipe or coiled tubing.

17. The down-hole assembly according to claim 16 , wherein said tubular is coiled tubing and wherein said down-hole assembly further comprises an indexing tool.

18. The down-hole assembly according to claim 15 , wherein said running tool includes a biasing means operatively associated with said window locator, said biasing means exerting a force on said pivoting arm of said window locator to bias said window locating head in a direction external of said running tool.

19. The down-hole assembly according to claim 15 , wherein in said run-in position, said window locating head is positioned between said retracted and said window locating positions and held stationary.

20. The down-hole assembly according to claim 19 , wherein in said run-in position, said window locating head is partially positioned external of said running tool for engagement with said main cased well bore.

21. The down-hole assembly according to claim 15 , wherein said shape of said lower section of said running tool is convex and said shape of said upper section of said guide member is concave.

22. The down-hole assembly according to claim 15 , wherein said lower section of said running tool and said upper section of said guide member are detachably connected by a shear bolt.

23. The down-hole assembly according to claim 22 , wherein said lower section of said running tool and said upper section of said guide member are further detachably connected by a dovetail joint.

24. The down-hole assembly according to claim 19 , wherein said running tool includes one or more shear pins affixed to said window locator, said shear pins maintaining said window locating head in said stationary position until sheared.

25. The down-hole assembly according to claim 15 , wherein in said retracted position, said window locating head is positioned substantially within said running tool, said window locating head being held in said retracted position by said main cased well bore.

26. The down-hole assembly according to claim 15 , wherein in said window locating position, said window locating head is biased in a direction external to said running tool and a portion of said window locating head is positioned within said window.

27. The down-hole assembly according to claim 26 , wherein said running tool includes a block means for restricting a maximum outward pivoting angle of said window locating head.

28. The down-hole assembly according to claim 27 , wherein said block means is L-shaped and includes a shoulder capable of receiving an outer edge surface of said window locating head.

29. The down-hole assembly according to claim 15 , wherein said stop means comprise one or more spring-loaded shear pins, said one or more spring loaded shear pins being actuated by displacement of said window locating head from said retracted position to said window locating position and deactivated by a shearing force, said deactivation resulting in said window locating head returning to said retracted position.

30. The down-hole assembly according to claim 15 , wherein said guide member includes a retrieval means, said retrieval means providing a point of operative attachment for a fishing tool.

31. A method of locating a window and reentering a lateral well bore in a main well bore from which a whip stock has been removed, comprising the steps of:

(a) deploying a tubular down said main well bore, said tubular containing a down-hole assembly, said down-hole assembly including a running tool having an upper section, a middle section and a lower section, said running tool including a window locator for locating said window, said window locator comprising a pivoting arm and a window locating head; a guide member having an upper section, a middle section and a lower section, said guide member having a wedged-shaped outer surface for diverting a down-hole tool through said window and into said lateral well bore; wherein said lower section of said running tool and said upper section of said guide member are each shaped to receive the other in mating relationship; wherein said lower section of said running tool and said upper section of said guide member are capable of being detachably connected, and when detachably connected, said running tool and said guide member are in fluid communication; wherein said window locating head has a run-in position, a retracted position, and a window locating position and wherein in said window locating position, said window locating head is biased in a direction external to said running tool and a portion of said window locating head is positioned within said window; and wherein said running tool includes a stop means for preventing retraction of said window locating head from said window locating position to enable determination of an upper edge of said window by pulling upward on said tool and of a lower edge of said window by pushing downward on said tool;

(b) activating said window locator so that said window locator is able to reposition to a window locating position external to said running tool when said running tool is placed adjacent said window;

(c) causing said window locator to reposition to said window locating position by placing said running tool adjacent said window;

(d) maintaining said window locator in said window locating position;

(e) determining the upper edge of said window and the lower edge of said window;

(f) positioning said guide member adjacent said window;

(g) anchoring said guide member in said main well bore;

(h) detaching said running tool from said guide member;

(i) pulling said running tool out of said main well bore; and

(j) deploying a second tubular containing said down-hole tool down said main well bore, through said window, and into said lateral well bore, said wedged-shaped outer surface of said guide member acting to divert said down-hole tool from said main well bore, through said window, and into said lateral well bore.

32. The method according to claim 31 , further comprising the step of:

(k) causing said down-hole tool to perform remedial work on said lateral well bore.

33. The method according to claim 32 , further comprising to steps of:

(l) removing the down-hole tool from the lateral well bore and the main well bore;

(m) deploying a third tubular containing a fishing tool down said main well bore;

(n) connecting said fishing tool to said guide member;

(o) disengaging said guide member from said main well bore; and

(p) pulling said guide member out of said main well bore.

34. The method according to claim 31 , wherein said main well bore is a cased well bore.

35. The method according to claim 31 , wherein said tubular is a work string, drill pipe or coiled tubing.

36. The method according to claim 35 , wherein said tubular is coiled tubing and wherein said down-hole assembly further comprises a indexing tool.