Patent ID: 8636085

Claim:
A method of removing laser effected debris from a borehole comprising: a. directing a high power laser beam having at least about 15 kW of power along a high power laser beam path towards a surface in a borehole; b. illuminating an area of the surface with a high power laser beam spot, whereby the high power laser beam spot spalls the area, creating laser induced spallation materials; c. contacting at least some of the laser induced spallation materials with a mechanical scraper; d. controlling an index of refraction of the environment through which the high power laser beam is directed; and, e. flowing a fluid along a fluid flow path, wherein the fluid flow keeps a portion of the high power laser beam path free from laser induced spallation materials, cools an optical component located in the high power laser beam path, and removes laser induced spallation materials from the borehole.