Systems and conveyance structures for high power long distance laser transmission

• US 10,036,232 B2
• Filed: 10/21/2013
• Issued: 07/31/2018
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: Foro Energy, Inc.
• Original Assignee: Foro Energy, Inc.
• Inventors: DeWitt, Ronald A., Zediker, Mark S., Faircloth, Brian O., Grubb, Daryl L., McKay, Ryan P., Gray, William C., Moxley, Joel F., Rinzler, Charles C., Underwood, Lance D., Deutch, Paul D.
• Primary Examiner(s): GAY, JENNIFER HAWKINS
• Application Number:
  US14/058,681
• Publication Number:
  US 20160222763A1
• Time in Patent Office: 1,744 Days
• Field of Search: 166 657, 166 771, 175 11, 175 15, 175 16, 175 57, 175162, 2191217, 21912172, 385100, 372 4
• CPC Class Codes: E21B 10/60 characterised by conduits or nozzles for drilling fluids for roller bits E21B10/18; for percussion drill bits E21B10/38
• CPC Class Codes: E21B 29/00 Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
• CPC Class Codes: E21B 37/00 Methods or apparatus for cleaning boreholes or wells E21B21/00 takes precedence
• CPC Class Codes: E21B 41/00 Equipment or details not covered by groups E21B15/00 - E21B40/00
• CPC Class Codes: E21B 7/14 Drilling by use of heat, e.g. flame drilling
• CPC Class Codes: E21B 7/15 of electrically generated heat
• CPC Class Codes: G02B 6/44 Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables cables incorporating electric conductors and optical fibres where features relating to the optical fibres are not of interest H01B11/22
• CPC Class Codes: H01S 3/04 Arrangements for thermal management

Abstract

There is provided a mobile high power laser system and conveyance structure for delivering high power laser energy to and for performing high power laser operations in remote and difficult to access locations. There is further provide such systems with high power laser, handling equipment and conveyance equipment that are configured to avoid exceeding the maximum bending radius of high power optical fibers used with the conveyance structures. There are also provided embodiments of the conveyance structures having channels, lines and passages for delivering materials such as fluids.

Claims

1. A mobile high power laser system configured for and capable of performing oil or gas field laser operations, the system comprising:

a laser cabin, the laser cabin housing a high power laser system having the capability to generate a laser beam having about 10 kW of power and a wavelength in the range of about 800 nm to about 2100 nm;

a conveyance structure having a length of 3,000 feet;

the conveyance structure comprising;

a high power optical transmission fiber, for transmitting the laser beam from the laser, having a core having a diameter of 500 μ

m and having a length of 3,000 ft, a first support structure having a length of 3,000 feet, a second support structure having a length of about 3,000 feet, a data or control line having a length of about 3,000 feet, and a passage defined by both the first and second support structures, the passage having a length of about 3,000 feet; and

a means for handling the conveyance structure; and

,

whereby the system is capable of delivering the high power laser beam 3,000 feet down a borehole.

2. The mobile high power laser system of claim 1, wherein the means for handling comprises an injector.

3. The mobile high power laser system of claim 2, comprising a second passage and wherein the line provides electric power.

4. The mobile high power laser system of claim 1, wherein the means for handling comprises a spool and an optical slip ring.

5. The mobile high power laser system of claim 1, comprising an optical block.

6. A mobile high power laser system comprising:

a laser cabin, the laser cabin housing a high power laser having the capability to generate a laser beam having about 10 kW of power;

a conveyance structure having a length of about 4,000 feet;

the conveyance structure comprising;

a high power optical transmission fiber, for transmitting the laser beam from the laser, having a core having a diameter of about 300 μ

m and having a length of about 4,000 feet, an outer support structure having a length of about 4,000 feet, an inner support structure having a length of about 4,000 feet, a data or control line having a length of about 4,000 feet, and a passage defined by the inner and the outer support structure, the passage having a length of about 4,000 feet; and

a means for handling the conveyance structure; and

,

whereby the system is capable of delivering the high power laser beam 4,000 feet down a borehole.

7. The mobile laser system of claim 6, wherein the lengths of the optical fiber, the outer support structure, the inner support structure, the line, and the passage are 5,000 feet.

8. The mobile laser system of claim 6, wherein the lengths of the optical fiber, the outer support structure, the inner support structure, the line, and the passage are about 10,000 feet.

9. The mobile high power laser system of claim 6, wherein the means for handling comprises an injector.

10. The mobile high power laser system of claim 6, wherein the means for handling comprises a spool and an optical slip ring.

11. The mobile high power laser system of claim 6, comprising a second passage and wherein the line provides electric power.

12. The mobile high power laser system of claim 6, comprising an optical block.

13. A mobile high power laser system comprising:

a. a base;

b. a means for providing a high power laser beam having 5 kW of power;

c. a handling apparatus having a radius of curvature and a means for containing the handling apparatus;

d. an operator station; and

,

e. a means for providing electrical power;

f. an optical fiber having a minimum bend radius and a core diameter of between about 500 μ

m and 1.5 mm; and

,

g. the handling apparatus radius of curvature configured to maintain the optical fiber within 1% of the optical fiber minimum bend radius, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

14. The mobile high power system of claim 13, wherein the base comprises a truck chassis;

wherein the means for providing the high power laser beam comprises a mobile laser room and wherein the mobile laser room is mounted to the truck chassis;

wherein the means for containing the handling apparatus comprises a handling apparatus cabin or a handling apparatus bay and comprises a handling apparatus comprising a high power conveyance structure, the conveyance structure having a length of about 4000 feet; and

wherein the operator station is controllably associated with the mobile laser room and the handling apparatus; and

,

whereby the system is capable of delivering the high power laser beam 4,000 feet down a borehole.

15. The mobile high power system of claim 13, wherein the base comprises a trailer;

wherein the means for providing the high power laser beam comprises a mobile laser room;

wherein the means for containing the handling apparatus comprises a handling apparatus cabin or a handling apparatus bay, and comprises a handling apparatus comprising a high power conveyance structure, the conveyance structure having a length of about 4000 feet, and is mounted to the trailer; and

wherein the operator booth is controllably associated with the mobile laser room and the handling apparatus; and

,

whereby the system is capable of delivering the high power laser beam 4,000 feet down a borehole.

16. A mobile high power laser system comprising:

a. a laser housing;

b. a handling apparatus;

c. a high power laser capable of generating a laser beam having a power of 10 kW within the laser housing;

d. a conveyance structure comprising a high power optical transmission fiber for transmitting the laser beam from the laser, a passage, a line and a support structure, wherein the high power optical fiber has a core, the core having a diameter of about 300 μ

m and a minimum bend radius; and

,

e. an optical block having a radius of curvature, wherein the optical block radius of curvature is within 5% of the minimum bend radius of the high power optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

17. The mobile high power laser system of claim 16, comprising 5,000 feet of conveyance structure and wherein the core has a diameter of 450 μ

m.

18. The mobile high power laser system of claim 17, wherein the high power laser is capable of generating a laser beam having a power of 20 kW.

19. The mobile high power laser system of claim 16, wherein the laser housing and the handling apparatus are associated with a platform.

20. The mobile high power laser system of claim 16, wherein the laser housing is associated with a first mobile base and the handling apparatus is associated with a second mobile base.

21. A mobile high power laser system configured for and capable of delivering a laser beam in a borehole, the system comprising:

a. a base;

b. the base having a laser housing, an operator housing and a handling apparatus;

c. a chiller, a storage tank, and a laser capable of generating a laser beam, the laser beam having a power of 10 kW, being associated with the laser housing;

d. a conveyance structure comprising a high power optical transmission fiber, for transmitting the laser beam from the laser, having a core diameter of between about 500 μ

m and 1.5 mm, a passage, a line and a support structure, wherein the high power optical fiber has a minimum bend radius; and

,

e. an optical block having a radius of curvature, wherein the optical block radius of curvature is equal to the minimum bend radius of the high power optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

22. The mobile high power laser system of claim 21,

wherein the conveyance structure has a length of 5,000 feet;

and,

whereby the system is capable of delivering the high power laser beam 5,000 feet down a borehole.

23. The mobile high power laser system of claim 22, wherein the support structure of the conveyance structure defines an outer surface for the conveyance structure.

24. The mobile high power laser system of claim 23, wherein the high power optical fiber is partially contained within the support structure.

25. The mobile high power laser system of claim 24, wherein the high power optical fiber forms a portion of the outer surface for the conveyance structure.

26. The mobile high power laser system of claim 23, wherein the wavelength of the laser beam is from about 800 nm to about 2100 nm.

27. The mobile high power laser system of claim 23, wherein the wavelength of the laser beam is from about 1060 nm to about 1800 nm.

28. The mobile high power laser system of claim 23, wherein the wavelength of the laser beam is from about 1800 nm to about 2100 nm.

29. The mobile high power laser system of claim 22, wherein the high power optical fiber and the line are inside of the support structure.

30. The mobile high power laser system of claim 21, comprising a second high power optical fiber and a passage.

31. The mobile high power laser system of claim 21, comprising a plurality of lines, a plurality of high power optical fibers, and a plurality of support structures.

32. The mobile high power laser system of claim 21, wherein the optical block is associated with the base.

33. The mobile high power laser system of claim 21, wherein the base is a trailer.

34. The mobile high power laser system of claim 21, wherein the base is a truck chassis.

35. The mobile high power laser system of claim 21, wherein the base is a skid.

36. The mobile high power laser system of claim 21, wherein a shipping container defines at least the laser housing.

37. The mobile high power laser system of claim 21, wherein the chiller is located within the laser housing and comprising:

air intake and exhaust means are associated with the chiller and provided in the laser housing; and

at least one storage tank comprises a heating element.

38. The mobile high power laser system of claim 21, wherein the high power optical fiber forms a portion of the outer surface for the conveyance structure and wherein the conveyance structure has a length of 3,000 feet and the optical fiber comprises a core having a core having a diameter of about 500 μ

m; and

, whereby the system is capable of delivering the high power laser beam 3,000 feet down a borehole.

39. A high power laser system comprising:

a. a mobile platform;

b. a laser housing associated with the mobile platform;

c. a chiller, and a laser capable of generating a laser beam having a power of 10 kW;

d. a conveyance structure having a length of 1,000 feet and comprising a high power optical transmission fiber and a protective structure, wherein the high power optical fiber has a core having a diameter of about 300 μ

m and a minimum bend radius; and

,

e. an optical block having a radius of curvature, wherein the optical block radius of curvature is within about 3% less than the radius of the minimum bend radius of the high power optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided; and

, whereby the system is capable of delivering the high power laser beam 1,000 feet down a borehole.

40. The high power laser system of claim 39, wherein the laser is capable of generating a laser beam having a power of 20 kW.

41. The high power laser system of claim 40, wherein the laser comprises a first laser capable of providing a laser beam having a power of 10 kW and a second laser capable of providing a laser beam having a power of 10 kW.

42. The high power laser system of claim 40, wherein the laser comprises a plurality of lasers each capable of generating a laser beam having a power, wherein the combined power of the plurality of laser beams has a power of 20 kW.

43. The high power laser system of claim 39, wherein the laser is capable of generating a laser beam having a power of 30 kW.

44. The high power laser system of claim 39, wherein the laser is capable of generating a laser beam having a power of 50 kW.

45. The high power laser system of claim 44, wherein the laser comprises a first laser capable of providing a laser beam having a power of 20 kW, a second laser capable of providing a laser beam having a power of 20 kW and a third laser capable of providing a laser beam having a power of 20 kW.

46. The high power laser system of claim 44, wherein the laser comprises a plurality of lasers each capable of generating a laser beam having a power, wherein the combined power of the plurality of laser beams has a power of 50 kW.

47. The high power laser system of claim 39, wherein the laser comprises a first laser capable of providing a laser beam having a power of 5 kW and a second laser capable of providing a laser beam having a power of 5 kW.

48. The high power laser system of claim 39, wherein the laser comprises a plurality of lasers each capable of generating a laser beam having a power, wherein the combined power of the plurality of laser beams has a power 10 kW.

49. The mobile high power laser system of claim 39, wherein the high power optical fiber forms at least a portion of the outer surface for the conveyance structure and wherein the conveyance structure has a length of 3,000 feet and the optical fiber comprises a core having a core diameter of 500 μ

m.

50. The mobile high power laser system of claim 39, wherein the conveyance structure comprises a passage.

51. The mobile high power laser system of claim 39, wherein the conveyance structure comprises a plurality of lines, a plurality of high power optical fibers, and a plurality of support structures.

52. A high power laser system comprising:

a. a mobile platform;

b. a laser housing associated with the mobile platform;

c. a laser capable of generating a laser beam having a power of 10 kW;

d. a conveyance structure comprising a high power optical transmission fiber, for transmitting the laser beam from the laser, and a protective structure, wherein the high power optical fiber has a minimum bend radius; and

,

e. the conveyance structure associated with a handling apparatus for holding and deploying the conveyance structure, wherein the handling apparatus is configured to maintain the radius of curvature for the optical fiber at a radius that is within 5% of the minimum bend radius, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

53. The high power laser system of claim 52, comprising a chiller.

54. The high power laser system of claim 53, wherein at least a portion of the chiller is exterior to the laser housing.

55. The high power laser system of claim 52, comprising an optical block.

56. The high power laser system of claim 52, wherein the handling apparatus is configured to maintain the radius of curvature for the conveyance structure at a radius within 1% of the minimum bend radius.

57. The high power laser system of claim 52, wherein the handling apparatus is configured to maintain the radius of curvature for the conveyance structure at a radius within 2% of the minimum bend radius.

58. The high power laser system of claim 52, wherein the handling apparatus is associated with a second mobile platform.

59. The high power laser system of claim 52, wherein the handling apparatus is associated with the mobile platform.

60. The mobile high power laser system of claim 52, wherein the high power optical fiber forms a portion of the outer surface for the conveyance structure and wherein the conveyance structure has a length of 3,000 feet and the optical fiber comprises a core having a core diameter of about 500 μ

m.

61. The mobile high power laser system of claim 52, wherein the conveyance structure comprises a line structure.

62. The mobile high power laser system of claim 52, wherein the conveyance structure comprises a plurality of lines, a plurality of high power optical fibers, and a plurality of support structures.

63. A high power laser system deployed at a well site, the system comprising:

a. a high power laser capable of generating a laser beam having a power of 10 kW;

b. a chiller;

c. a conveyance structure deployment device;

d. an optical block;

e. a conveyance structure having a distal end and a proximal end and comprising a high power optical transmission fiber, for transmitting the laser beam from the laser, having a minimal bend radius;

f. a lubricator;

g. wherein the proximal end of the conveyance structure is optically associated with the high power laser and associated with the deployment device;

wherein the conveyance structure is partially held by the deployment device and extends from the deployment device to the optical block and extends from the optical block to and into the lubricator, thereby defining a conveyance structure deployment path;

wherein the lubricator is in communication with a well at the well site; and

,

h. the conveyance structure deployment path does not exceed the minimum bend radius for the optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

64. The high power laser system of claim 63, comprising a generator.

65. The mobile high power laser system of claim 63, wherein the conveyance structure comprises a plurality of lines, a plurality of high power optical fibers, and a plurality of support structures.

66. The high power laser system of claim 63, wherein the laser system is mounted on a mobile platform.

67. The high power laser system of claim 66, wherein the mobile platform is a truck.

68. The high power laser system of claim 66, wherein the mobile platform is a trailer.

69. The high power laser system of claim 63, wherein the laser comprises a first laser capable of providing a laser beam having a power of 10 kW and a second laser capable of providing a laser beam having a power of 10 kW.

70. The mobile high power laser system of claim 63, wherein the high power optical fiber forms at least a portion of the outer surface for the conveyance structure and wherein the conveyance structure has a length of 3,000 feet and the optical fiber comprises a core having a core diameter of about 300 μ

m; and

, whereby the system is capable of delivering the high power laser beam 3,000 feet down a borehole.

71. The mobile high power laser system of claim 63, wherein the conveyance structure comprises a data or control line.

72. The mobile high power laser system of claim 63, wherein the conveyance structure comprises a passage.

73. The mobile high power laser system of claim 64, wherein the conveyance structure comprises a passage.

74. A high power laser system deployed at a well site, the system comprising:

a. a means for generating a high power laser beam, wherein the laser beam has a power of 10 kW;

b. a means for deploying a conveyance structure;

c. a conveyance structure having a distal end and a proximal end and comprising a high power optical transmission fiber, for transmitting the laser beam from the laser, having a minimal bend radius and having a core diameter of 300 μ

m;

d. a means for entering a well;

e. wherein the proximal end of the conveyance structure is optically associated with the high power laser;

wherein the conveyance structure is held by the means for deploying and extends to and into the means for entering a well, thereby defining a conveyance structure deployment path;

wherein the means for entering the well is in communication with a well at the well site; and

,

f. the conveyance structure deployment path does not exceed the minimum bend radius for the optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

75. A laser work over and completion unit comprising:

a. a base;

b. a handling apparatus associated with the base;

c. a means for receiving a laser beam, wherein the laser beam has a power of 5 kW, wherein the receiving means is associated with the handling apparatus;

d. a conveyance structure comprising a means for transmitting a laser beam a distance from the laser, wherein the laser beam has a power of 5 kW, over a distance, the distance comprising 3,000 ft, without substantial power loss;

a passage, a line and a support structure, wherein the means for transmitting has a minimum bend radius and a core diameter between about 500 μ

m and 1.5 mm; and

,

e. an optical block having a radius of curvature, wherein the optical block radius of curvature is greater than, equal to, or within 5% less than the minimum bend radius of the means for transmitting, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided; and

,

f. whereby the system is capable of delivering the high power laser beam 3,000 feet down a borehole.

76. The unit of claim 75, wherein the conveyance structure has a length of 5,000 feet and comprising a means for transmitting a laser beam having 5 kW of power over the length of the conveyance structure.

77. The unit of claim 75, wherein the conveyance structure has a length of 10,000 feet and comprising a means for transmitting a laser beam having 5 kW of power over the length of the conveyance structure.

78. The unit of claim 75, wherein the support structure of the conveyance structure defines an outer surface for the conveyance structure.

79. The unit of claim 75, comprising a high power laser capable of generating a laser beam having 5 kW of power.

80. The unit of claim 75, wherein the means for transmitting is partially contained within the support structure.

81. The unit of claim 75, wherein the means for transmitting forms a portion of an outer surface for the conveyance structure.

82. The unit of claim 75, wherein the conveyance structure comprises a plurality of lines, a plurality of high power optical fibers, and a plurality of support structures.

83. A laser workover and completion system deployed at a well site, the system comprising:

a. a conveyance structure deployment device;

b. an optical block;

c. a conveyance structure having a distal end and a proximal end and comprising a high power optical transmission fiber, for transmitting the laser beam from the laser, with a core diameter of between about 500 μ

m and 1.5 mm, having a proximal end and a distal end, and having a minimal bend radius, the proximal end of the high power optical fiber being capable of receiving a high power laser beam and the high power optical fiber being capable of transmitting a high power laser beam without substantial power loss;

d. a lubricator;

e. wherein the proximal end of the conveyance structure is associated with the deployment device;

f. wherein the conveyance structure is at least partially held by the deployment device and extends from the deployment device to the optical block and extends from the optical block to and into the lubricator, thereby defining a conveyance structure deployment path;

g. wherein the lubricator is in communication with a well at the well site; and

,

h. the conveyance structure deployment path does not exceed the minimum bend radius for the optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

84. A laser workover and completion system deployed at a well site, the system comprising:

a. a conveyance structure deployment device;

b. an optical block;

c. a conveyance structure having a distal end and a proximal end and comprising a high power optical transmission fiber having a core diameter between about 500 μ

m and 1.5 mm and a minimal bend radius;

d. a means for entering a well;

e. wherein the proximal end of the conveyance structure is optically associated with the high power laser and associated with the deployment device;

f. wherein the conveyance structure is at least partially held by the deployment device and extends from the deployment device to the optical block and extends from the optical block to and into the means for entering a well, thereby defining a conveyance structure deployment path;

g. wherein the means for entering the well is in communication with a well at the well site; and

,

h. the conveyance structure deployment path does is within 5% of the minimum bend radius for the optical fiber, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.

85. A high power laser conveyance structure comprising:

a. a first layer comprising a plurality of wound armor wires;

b. a second layer comprising a plurality of wound armor wires, wherein the second layer is positioned inside of the first layer;

c. the second layer forming a cavity;

d. the cavity containing a high power optical transmission fiber having a core diameter between about 500 μ

m and 1.5 mm and having a minimum bend radius;

e. the high power optical fiber comprising a core and a cladding;

f. the high power optical fiber configured to reduce a non-linear effect when a high power laser beam is propagated through the optical fiber, whereby non-liner effects on the transmission of the laser beam are reduced; and

,

g. the conveyance structure having a length of 1,000 feet; and

,

h. whereby the system is capable of delivering the high power laser beam 1,000 feet down a borehole.

86. The high power laser conveyance structure of claim 85, having a length of 5,000 feet.

87. A high power laser conveyance structure comprising:

a. a first layer comprising a plurality of wound armor wires;

b. a second layer comprising a plurality of wound armor wires, wherein the second layer is positioned inside of the first layer;

c. the second layer forming a cavity;

d. the cavity containing a plurality of electrical conductors and a high power optical transmission fiber;

e. the high power optical fiber comprising a core having a core diameter between about 500 μ

m and 1.5 mm and having a minimum bend radius, a cladding and a protective layer;

f. the high power optical fiber configured to reduce a non-linear effect when a high power laser beam is propagated through the optical fiber, whereby non-liner effects on the transmission of the laser beam are reduced; and

,

g. the conveyance structure having a length of 2,000 feet; and

,

h. whereby the system is capable of delivering the high power laser beam 2,000 feet down a borehole.

88. The high power laser conveyance structure of claim 87, having a length of 5,000 feet.

89. A high power laser conveyance structure comprising:

a. a support structure;

b. a line associated within the support structure;

c. a high power optical transmission fiber associated with the support structure;

d. a passage associated with the support structure for transporting a fluid; and

,

e. the high power optical fiber having a core diameter between about 500 μ

m and 1.5 mm and having a minimum bend radius, and configured to reduce a non-linear effect when a high power laser beam is propagated through the optical fiber over a distance, the distance have a length of 2,000 feet; and

,

f. whereby the system is capable of delivering the high power laser beam 3,000 feet down a borehole.

90. The conveyance structure of claim 89, wherein the conveyance structure has an outer surface comprising the support and wherein the line is associated with the outer surface.

91. The conveyance structure of claim 89, wherein the conveyance structure has an outer surface comprising the support and wherein the fiber is associated with the outer surface.

92. The conveyance structure of claim 89, wherein the passage is defined by the support structure.

93. The conveyance structure of claim 89, comprising a second support structure.

94. The conveyance structure of claim 89, comprising a second passage.

95. The conveyance structure of claim 89, wherein the fluid is selected from the group consisting of air, gas, nitrogen, and liquid.

96. The conveyance structure of claim 89, wherein the support structure comprises a material selected from the group consisting of wire, carbon fiber, composites, polymers, and metal tubing.

97. A high power laser system comprising:

a. a mobile platform;

b. a laser housing associated with the mobile platform;

c. a laser system capable of generating a laser beam having 10 kW of power;

d. a conveyance structure comprising a high power optical transmission fiber having a core diameter between about 500 μ

m and 1.5 mm and having a minimum bend radius and a protective structure, wherein the high power optical fiber has a minimum bend radius; and

,

e. the conveyance structure associated with a handling apparatus for holding and deploying the conveyance structure, wherein the handling apparatus is configured to maintain the radius of curvature for the optical fiber at a radius that is within 5% of the minimum bend radius, whereby transmission losses of the high power laser beam from macro-bending, micro-bending and strain are avoided.