World progress of drilling and production test of natural gas hydrate

Since the natural gas hydrate was recognized as a new energy source in 1960s, the research of gas hydrate has made great progress. Similar to the conventional oil and gas, the development of hydrate also needs to pass two important stages, i.e. exploration and production test. This paper summarized and analyzed the progress in exploration drilling and production test of hydrate in some major countries. The exploration drilling plays a critical role in data acquisition, hydrate sampling, and optimization of relevant technology, equipment and facilities, whereas the production test aims to test the efficiency of technology for industrial development of gas hydrate in a safe, stable and efficient way. As one of the leading countries in hydrate research in the world, China has made great progress in hydrate exploration and resource assessment, and the recent production test is really a great success. Further development in exploitation technology and related facilities is discussed and recommended in the paper.