2018 Volume 83 Issue 5 Pages 331-341
In the last two decades, seven field operations have been executed for drilling and for production-testing of natural methane hydrate as a national project to seek its potential of energy source. In this lecture, objectives, outcomes and challenges of each field operation are introduced from the viewpoint of operator. All challenges in these step-by-step field operations have been developmentally succeeded to the achievement of the most recent 2nd offshore production test in 2017.