Experimental Investigation of Specific Energy of Rocks by Low Power Laser Drilling

摘要

Specific energy is the amount of energy required for a specified volume of rock to be destroyed. This is a normalization method used to compare the efficiency of destruction of rocks. In this study, low power laser beam of Free Electron Laser (FEL) has been used to penetrate different reservoir carbonate rocks and shales in Ahvaz Oil Field. The corresponding specific energies and ROPs are measured. laser beam is shown to be capable of drilling boreholes because of the high energy it can create. Laser is shown to drill shales while preventing the clay swelling problem prevailing when water is in contact with shales. Laser can also increase the accuracy of perforation of casing strings. The core samples tested were taken from Asmari member Sandstone, Asmari limestones and Khami shale. Comparison of different laser modes in terms of specific energy and ROP increase has been investigated which has not been accounted for in many previous works. As the future work, shape and rock type should be considered although there exist many works in literature wherein these parameters have been neglected.