南海神狐海域天然气水合物注热降压开采数值模拟研究  

Numerical Studies of Gas Production from Gas Hydrate Zone Using Heat Injection and Depressurization in Shenhu Area,the South China Sea

作　　者：胡立堂[1,2] 张可霓[1,2] 高童[1,2] 

机构地区：[1]北京师范大学水科学研究院,北京100875 [2]北京师范大学地下水污染控制与修复教育部工程研究中心,北京100875

出　　处：《现代地质》2011年第4期675-681,共7页Geoscience

基　　金：中国科学院广州天然气水合物研究中心开放基金(o807s1)

摘　　要：针对南海神狐海域天然气水合物成藏条件,利用pT+H软件和水平井技术对天然气水合物的注热和注热降压开采效果进行了模拟分析。重点讨论了注入热水温度为30、60、90℃时水合物饱和度以及CH4气体饱和度、CH4产气率、累积CH4产气量和产水量的变化规律,发现两种开采模式下水合物低饱和度分布范围随时间增长和温度升高而增大;CH4产气率在开采10 d内升高较快,之后逐渐减小。模拟结果表明:注热降压开采模式比单纯注热模式的效果有较大改善,而且温度对于提高CH4产气量效果不明显,但因为天然气水合物藏的低渗透性,神狐海域的天然气水合物的CH4产气量不大。研究结果可为南海神狐海域和类似地区天然气水合物开采提供参考。Based on geologic conditions of natural gas hydrate deposits,this paper used pT＋H software and horizontal wells to evaluate gas production strategies including heat injection and combined use of heat injection and depressurization.This paper discussed the change of the saturation of gas hydrate,the saturation of CH4 in gas phase,the production rate of CH4 in gas phase,cumulative CH4 production,and water production when injecting water temperature is 30,60 and 90 ℃.It was found that the distribution area of low hydrate saturation increases with increasing time and temperature,and the production rate of CH4 increases rapidly within 10 days and then decreases gradually.The results verified the advantages of combine method of heat injection and depressurization,and demonstrated the temperature is not sensitive to the production rate of CH4.It was found that cumulative CH4 volume in Shenhu area is not big mainly because of the low permeability.The findings can provide the references for gas production of natural gas hydrates in Shenhu area,the South China Sea or similar areas.

关 键 词：水合物 水平井 CH4产气率 注热降压 TOUGH2 神狐海域 

分 类 号：P744.4[天文地球—海洋科学] P618.13