摘要
采用TOUGH+HYDRATE数值模拟工具,探讨降压开采方案下天然气水合物藏(无下伏游离气水层)开采的地质参数。以单次单因子敏感性分析方法为基础,在统一变化幅度范围内研究某一储层参数(温度、压力、孔隙度、渗透率、水合物饱和度、地层厚度)的变化在60天短期与5年长期开采中对水合物开采结果的定性影响关系,并以变量敏感度为依据,定量计算储层地质参数对水合物开采评价指标的敏感度值。结果发现,在整个开采周期内,储层温度与分解气体量及产气量之间有较强的相关性;当水合物储层压力增大时,水合物分解气体体积随之减小,而在60天开采中,储层压力增大使得产气量增大,在5年开采中,储层压力的变化对产气量基本无影响,另外,储层压力与产水量之间呈线性增加的关系;水合物总分解气体量、总产气量与孔隙度之间呈负相关关系,但对产气量的变化影响相对较小;渗透率对水合物开采有明显的影响;水合物前期分解气体体积与产水量随水合物饱和度的增大而减小;在60天开采中,水合物厚度越大反而不利于水合物分解,但5年开采中,地层厚度增大,水合物分解量增大。另外,通过对地质参数敏感度计算发现,无论是以哪一开采指标作为水合物开采潜力的评价标准,水合物地层温度、地层压力以及绝对渗透率是三个至关重要的地质参数。
In this paper,TOUGH+HYDRATE was used to study the geological parameters affecting the production of gas hydrate reservoirs.The geological parameters affecting the production were intensively investigated.Based on the method of single-factor sensitivity analysis,the change of a certain geological parameter on the hydrate production behavior was studied within the unified range of variation for short or long production period(60 days or 5 years).Taking variable sensitivity as a reference,the sensitivity values of reservoir geological parameters to hydrate production evaluation indices were quantitatively calculated.The results showed that during the entire production,there was a strong correlation between reservoir temperature and gas production volume.When the pressure of hydrate reservoir increased,the gas volume of hydrate decomposition decreased.In 60 days of production,increasing reservoir pressure leads to increased gas production.In long-term production,the change in reservoir pressure had no effect on gas production.In addition,there was a linear increase relationship between reservoir pressure and water production.The gas volume and porosity were generally negatively correlated,while the influence on the change of gas production was relatively small.Intrinsic permeability had a significant impact on hydrate production.The gas volume of hydrate decomposition and water production in the early stage decreased with the increase of hydrate saturation.In 60 days production,the larger the hydrate thickness was,the worse the hydrate decomposition.However,in the 5-year production,the amount of hydrate decomposition increased with the increase of the formation thickness.No matter which production rule was used as the evaluation standard of hydrate production potential,the temperature,pressure and absolute permeability of hydrate formation were three important geological parameters.
作者
彭盈钰
金光荣
苏正
刘丽华
刘杰
翟海珍
PENG Ying-yu;JIN Guang-rong;SU Zheng;LIU Li-hua;LIU Jie;ZHAI Hai-zhen(Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China;CAS Key Laboratory of Gas Hydrate,Guangzhou 510640,China;Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《新能源进展》
2021年第2期133-142,共10页
Advances in New and Renewable Energy
基金
广州市科技计划项目(201804010372)
“广东特支计划”本土创新创业团队项目子项目(2019BT02L278-01)
2019年省级促进经济发展专项资金项目(GDOE[2019]A41)
中国科学院南海生态环境工程创新研究院项目(ISEE2020YB05)
广东省海洋科技协同创新中心项目(20180207)
广州市科技计划项目(201804010264)。
关键词
天然气水合物
地质参数
降压开采
敏感性
gas hydrate
geologic parameters
depressurization
sensitivity analysis
