Patent ID: 7487834

Claim:
A method for perforation of oil and gas well casings and rock formations utilizing a high power laser beam to perforate the casing, and cement and form penetrations into a rock formation to enhance the flow of gas and oil into the wells comprising the steps of: delivering a high power laser beam to a laser perforator located in a production zone of a borehole; bending, tilting and shaping the high power laser beam to the desired beam orientation and profile; providing a nozzle coupled to said laser perforator for providing a purging flow to move spalled rock fragments out of the hole and to create a stable clear path removing wellbore liquid for the laser beam to reach the rock surface while perforating; focusing and offsetting the laser beam on the steel casing and rotating the focused laser beam to cut a hole through the steel casing; defocusing the laser beam by one-half diameter of the hole to be perforated and offsetting the laser beam by about one-half beam diameter from the center of the hole to be perforated and rotating the offset laser beam around the axis of the hole to perforate a hole into the cement and rock; the laser beam having an irradiance and rotation speed set for material removal by laser spallation and having a tilting angle set for minimum hole tapering.