Abstract:
Laser perforation is a forward-looking technology in the oil well completion engineering, which has great application value for improving oil recovery. In order to improve the laser power and laser transmission safety used in oil well laser perforation, 10 kW-laser space incoherent combining was realized by using 19 fiber-transmitted 972 nm semiconductor lasers. By studying the effect of the radii, separation distances of collimated laser beams on the spot overlapping efficiency of combined laser beam, and simulating cross section energy distribution of combined laser beam, the structure design of a 191 space incoherent beam combiner was completed. A space incoherent combined laser beam with a single beam shape was achieved within the beam combining length of 300 mm, with a maximum combined power of 10.441 kW, a focal spot diameter of 21 mm, a line width of 2.46 nm and a combined efficiency of 98.2%. Ground laser perforation experiments for sandstone and steel plate were performed using the 10 kW spatial incoherent beam laser with perforation depths of 570 mm and 70 mm, respectively.