Elemental Analysis of Bitumen and Crude Oil Samples by Laser Induced Breakdown Spectroscopy
Bitumen samples were analyzed using an Ocean Optics LIBS 2500 system with a Nd-YAG laser (1064 nm wavelength) in Ar, He, and air. Optimal operating conditions were Q-switch delay time of -3.0 ms and laser energy of 211 mJ. Sulfur peaks are present in He saturated environments; in Ar, S peaks interfere with a large Ar peak, and S peaks are absorbed in air. Analyzing in Ar has the expected effect of increasing peak/background; Ni and V peaks were present in Ar but absent or subdued in He and air.
LIBS analysis would allow crude oil samples to be immediately and accurately analyzed on site, giving operators timely and critical information, also eliminating unnecessary sample destruction. LIBS would also be invaluable in analyzing piston core extracts where typically sample size is too small for elemental analysis. Therefore, LIBS could further aid exploration in key areas where there is little to no available well data.