Study On Drilling Technology Of Laser Assisted Rock Breaking

Energy security is a major issue which is related to the nation's safety and the people's livelihood.In the complicated international situation,keeping the energy exploration and development continuous and shortening their cycle time is the key point to ensure national energy security.And in the field of oil and gas exploration,improving drilling efficiency and shortening well construction cycle is one of the most important tasks to esure national petroleum security.Especially,with the development of oil and gas exploration to deep and ultra deep wells,more and more difficult formations are encountered in oil drilling.Under the traditional rotary drilling system,the ROP can be improved by improving the mechanical parameters,using the downhole tools and the optimum design of the drill bit.However,the performance of theses methods is not good enough.As a kind of high energy density rock breaking tool,laser is being paid more and more attention by oil and gas industry.In this paper,the domestic and foreign research on the development of the laser assisted rock breaking technology as well as their present technical situation have been investigated.It is also compared between the existing rock breaking technology and laser rock breaking technology.This paper puts forward the study idea of laser assisted rock breaking drilling technology,which is based on the existing rotary drilling technology and laser rock breaking technology,by which drilling ROP is enhanced.Based on the study of laser assisted rock breaking method and influence of laser thermal action on rock mechanics parameters,laser assisted rock breaking mechanism is analyzed.The effect of laser rock breaking and laser assisted rock breaking is compared.Meanwhile,by laser assisted rock breaking experiment on igneous rock and sandstone,the efficiency of laser rock breaking under different parameters is analyzed and compared.Based on the most widely used rotary drilling system,the selection of laser and the design of laser drill bit and double eyelid laser head are completed.Finally,technical scheme of laser assisted rock breaking drilling technology based on downhole laser and ground laser is separately formed.