Engineering characteristics of laser perforation with a high power fiber laser in oil and gas wells

We report a laser perforation presentation with a 6 kW fiber laser in oil and gas wells. Temperature distribution on the rock surface after laser irradiation was numerically analyzed. High power fiber laser perforating experiment was carried out in conditions of different rock types, rock deposition orientations, rock sizes, laser output powers, laser irradiation time and other factors. When boundary effects are eliminated, the rock size and rock deposition orientation have no effect on perforation efficiency. The highest perforation efficiency and the maximum thermal expansion coefficiency of rock are obtained at the same time when laser power reaches a specific value, and the laser perforation efficiency decreases with the increasing of irradiation time.