Key Production Test Technologies for Offshore Natural Gas Hydrate

Taking intothe differences in development technologies for offshore natural gas hydrate (NGH) and conventional offshore oil and gas, this paper discusses the characteristics of NGH reservoirs and the challenges in NGH production tests. Key technologies for NGH production tests were presented, including managed-pressure drilling (MPD), cased drilling, inhibitive drilling fluid, drilling fluid cooling system, low-temperature and low-heat cement slurry system, completion technique, production method optimization, reservoir and environment monitoring, etc. It is proposed that research for offshore NGH production test in China should focus on physical and mechanical properties of hydrates, safe well construction, continuous production and sand control, adaptability evaluation of production method, and reservoir parameter and formation deformation monitoring during production test. Moreover, demonstrative projects should be adopted to create the offshore NGH production test technologies, so as to provide reliable support for development of offshore NGH effectively in China.