Based on the brief review of the progresses on the natural gas hydrate exploration, this paper presents a concept development method for offshore natural gas hydrate, considering the current deepwater engineering practice. A set of one dimension experimental facility has been built to simulate the natural gas hydrate development process. The experimental studied of the depressurization and heat injection method used for produce natural gases from hydrates have been carried out. The hydrate dissociation kinetics, gas and water production rate have been analyzed, which are meaningful for the pilot scale and real industry scale production of natural gas hydrate.
The natural gas hydrate, named as "burning ices", is one kind of unconventional energy with the high energy density, wide distribution and vast quantities. In general, they are stored in permafrost regions and deepwater areas with water depth deeper than 300m. It is estimated that the total resource of hydrate is equal to 1.8–2.1*1016 m3 methane gases, which is double to that current known carbon energy resource (oil, coal, natural gas etc.) all over the world. Globally, there are 84 offshore areas with hydrate have been detected directly or indirectly, among them more than 20 sites have obtained the natural gas hydrate core successfully. The trial productions of gases from the hydrate reservoir in the permafrost areas have also been carried out. Some important evidences, such as BSR, carbonate shell, have been observed in the east sea mainland sloping、seabed groove、northern-eastern swoop areas in south sea、northern mainland sloping in south sea etc. How to exploit and utilize the natural gas hydrate, one of the most promising and potential clean new energy resource, is and will being the focus of not only china but also other countries.
