Laser drilling: reviewing the effect of purging system and formation parameters

Abstract

Laser drilling is capable of reducing drilling costs and time. In laser drilling, a high rate of penetration (ROP) can be achieved, and the hole is cased due to laser interaction once it is drilled. In addition, laser technology can substitute conventional perforation techniques with no formation damage. Rock cutting with a laser beam is affected by various variables that fall within three categories; the rock parameters, purging system and experimental setup, and laser parameters. Each set of these categories affects the rock lasing process. Formation parameters include rock type, sample size, orientation, and the type of fluids saturating the rock sample. The purging system parameters include the type of purging system, application parameters, and the purging medium. Laser parameters involve laser type, laser application mode, beam power, duration, intensity, and frequency.This paper reviews several experimental works performed by institutes, researchers, and entities to provide the reader with a comprehensive knowledge base for further experimental work, modeling for laser drilling, and studies. Because performed laser drilling experimental work is huge and covers tremendous aspects, only the purging system and effect of formation parameters were considered in this review, while laser parameters will be presented in a later paper. Results showed that the laser can drill swiftly through all rock types in conventional vertical, directional, or horizontal drilling. For optimum laser drilling, the purging system and its parameters must be carefully chosen, including the type of system, purging gas, gas pressure, distance to the lased sample surface, and the purging angle. The optimum purging system uses nitrogen as a purging fluid.