摘要
为了推动我国海洋天然气水合物(以下简称水合物)藏实现高产能开发,为我国尽早实现海洋天然气水合物商业化开发提供技术支撑,以下伏气的水合物藏降压开采为研究目标,分析了最小井底流压、储层渗透率及井型等参数对水合物和下伏气联合降压法开采时产能的影响。研究结果表明:(1)渗透率一定的情况下,井底最小流压越小,高峰日产气量越大,最终累产气量越多;(2)渗透率对产能影响很大,当水合物和浅层气渗透率不同时,水合物层渗透率小于2.5 mD且浅层气渗透率小于15.0 mD时,无法达到日均5×10^(4)m^(3)的产能;当水合物和浅层气渗透率相同时,储层渗透率大于8.0 mD时,可以达到日均5×10^(4)m^(3)的产能;(3)分支井的开发效果优于水平井和定向井的开发效果。结论认为,储层渗透率对水合物和下伏气联合降压法开采影响较大,在联合开采过程中,需要加强储层取样及测试数据分析,明确水合物和浅层气层有效渗透率。
In order to promote high-productivity development of marine gas hydrate reservoirs in China and provide technical help for hydrate’s commercial exploitation as soon as possible,this paper analyzes the influence of minimum bottomhole flowing pressure,permeability and well type on the productivity during the commingled production of both gas hydrate and its underlying gas by depressurization.Results show that (1) at a certain permeability,the lower the minimum flowing pressure,the larger the peak daily gas production and cumulative gas production;(2) the influence of permeability on productivity is quite significant.When the permeability of hydrate is different from that of shallow gas,and they are less than 2.5 mD and 15.0 mD,respectively,the average productivity may not reach 5×10^(4)m^(3)/d.When their permeabilities are the same or higher than 8.0 mD,this average productivity of 5×10^(4)m^(3)/d can be obtained;and (3) lateral wells is superior to both horizontal and directional ones in the development effect.In conclusion,reservoir permeability has a greater inpact on the commingled production of both gas hydrate and its underlying gas by depressurization.In this production process,it is essential to strength reservoir sampling and data analysis,so as to determine the effective permeability in hydrate and shallow gas reservoirs.
作者
温慧芸
WEN Huiyun(State Key Laboratory of Natural Gas Hydrate,Beijing 102209,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)
出处
《天然气技术与经济》
2022年第5期38-44,共7页
Natural Gas Technology and Economy
基金
中海石油(中国)有限公司科研课题“天然气水合物国家重点实验室2022年自主前瞻基础研究课题”(编号:2022-KJYFPT-SHW)。
