中文摘要：

天然气水合物作为一种新型替代能源,已成为当前研究的热点,但目前对于南海北部陆坡神狐天然气水合物的开采效率和经济可行性仍没有清楚的认识。以南海北部陆坡神狐海域SH2站位的天然气水合物产出特征为依据,构建了神狐天然气水合物垂直单井开发的物理模型,利用TOUGH＋HYDRATE程序,数值模拟研究了对神狐天然气水合物藏进行降压开采的潜力,并以水合物分解效率和气体产能为绝对标准,以产水量和气水体积比为相对标准,评价了神狐天然气水合物在垂直单井开发中的经济可行性。在整个模拟开采过程中没有发生冰阻现象,未见次生水合物发育,水合物分解速率和井孔产气速率持续降低,并在开采进行1 300 d时出现跳跃性衰减,而产水量持续增长,气水体积比维持较低水平。研究显示,对神狐天然气水合物采用简单的垂直单井开发不具有经济可行性。

英文摘要：

Natural gas hydrate is a new potential energy,but how to effectively produce the gas from hydrate deposits remains a hot research topic.The production efficiency and economic feasibility of gas production from hydrate deposits at Shenhu area on the northern continental slope of South China Sea have not been thoroughly investigated so far.In this paper,a physical model is constructed for producing gas from Shenhu hydrate deposits through a vertical well.The production potential has been numerically simulated using the TOUGH＋HYDRATE simulator with parameters from the drilling site of SH2 in the area.The economic feasibility for hydrate exploitation at the Shenhu is evaluated using both the absolute criteria of hydrate dissociation rate and gas production efficiency and the relative criteria of water production and the volumetric ratio of gas to water.In the whole course of mining simulation,ice obstacle did not appear,and secondary hydrate was not observed,both the hydrate dissociation rate and gas production rate at the well decreased continuously,and even had a jumping attenuation at time of 1300 d since the production got started.But the water production had a continuous increase and the volumetric ratio of gas to water remained at low level.The research shows that producing gas from Shenhu hydrate deposits through a simple vertical well is not economically feasible.