Feasibility of application of hydraulic jet micro-borehole technology to marine hydrate drilling

Abstract:

In the post-petroleum era, natural gas hydrate has become the best energy source for exploitation. It has the characteristics of abundant reserves, cleanliness and high efficiency. Countries all over the world attach great importance to the investigation and exploitation of natural gas hydrate resources. In 2017, China successfully implemented the vertical well production test of marine natural gas hydrate, and achieved fruitful results. The hydraulic jet micro-wellbore technology is a new drilling technology that has been developed and applied in oil drilling; and its application to marine natural gas hydrate drilling has the advantages of low drilling cost, smooth drilling of the horizontal section, less difficulty in control of the well trajectory, small reservoir pollution, and reduced risk of large-scale seabed collapse. But there are still some key technical issues remained for solution, such as the length of the horizontal section, the stability of the borehole, the handling of stuck drills, the development of drilling tools, the short life of coiled tubing.

Key words:marine drilling; marine natural gas hydrate; hydraulic jet micro-borehole; drilling technology