The Effect of High Power Laser on Organic-Rich Shales

The objective of this work is to characterize the effect of a high power laser (HPL) on organic-rich shales. The analysis combines machine learning with advanced characterizations to reveal the geochemical and mechanical transformations induced by high power laser in source rocks. Lab results showed that HPL improves permeability, increases porosity, modifies the mechanical structure of the rock, and may positively affect the maturity of source rocks. A high power laser was used in the lab to perforate and heat different types of source rocks with varying organic content. The process was characterized in real time using near-infrared spectroscopy and mid-IR thermography. The pre- and post-characterization process draws on different tools to evaluate the chemical and structural transformations induced by the HPL processes. This step included several spectroscopy techniques (e.g., FTIR, UV/VIS/NIR), Rock-Eval, and differential thermal analysis (DTA). The analysis leverages on clustering techniques to reveal the distinct effects of HPL on source rocks. The spectroscopy and geochemical analyses revealed that that HPL modifies the molecular structure of the rock. Yet, the fundamental structure of the rock remains intact. The changes are revealed by clustering analysis of the FTIR data before and after laser heating. The analysis show the formation of clusters after the process, which correspond to the maturation of the organic content. The success of the lab work proved that high power laser could enhance the properties of source rocks. The effects include permeability improvement, enhanced porosity, and changes in the molecular distribution of the organic content. The results of the analyses suggest that the laser can drive forward the maturity of the source rock. This work also illustrates how machine learning and multiphysics characterization can reveal the dynamics of the HPL processes and their effects. Ultimately, the outcome of this study will contribute to the development of novel HPL applications.