天然气工业2018，Vol.38Issue(1)：49-55,7.DOI:10.3787/j.issn.1000-0976.2018.01.006
致密气核磁共振测井观测模式及气水弛豫分析——以四川盆地为例
NMR logging activation sets selection and fluid relaxation characteristics analysis of tight gas reservoirs: A case study from the Sichuan Basin
摘要
Abstract
With complex lithology and reservoir types,as well as high concealment and heterogeneity,tight reservoirs in the Sichuan Basin involve significant uncertainties in gas-water relationship.Since NMR logging can effectively solve problems related to the multiple results of conventional logging operations,it can be deployed for accurate assessment of the properties of formation fluids.Accordingly,different NMR logging activation sets were assessed in accordance with the specific features of tight reservoirs in the basin.With consideration to NMR logging data obtained under different activation sets and testing data of wells,the optimal NMR logging activation set was identified.Moreover,with relaxation characteristics of rocks,gas and water as theoretical foundations,the T2 gas and water relaxation characteristics were reviewed to highlight the impacts of porosity,pore sizes,fluid properties and other factors of tight reservoirs on T2 horizontal relaxation distribution.According to the research results,D9TWE3 can be seen as the most suitable NMR logging activation set for tight reservoirs in the Sichuan Basin;reservoir tightness is the key influence factor for the distribution of gas/water relaxation in tight clastic reservoirs;generally,in tight sandstone reservoirs,natural gas shows a longer T2 relaxation time than water;in fracture-vug type carbonate reservoirs,the right peak of T2 distribution spectrum of gas layers is frontal,while the right peak in T2 distribution spectrum of water layers is backward.In conclusion,the standards for gas/water relaxation in tight sandstone and carbonate reservoirs in the Sichuan Basin can help effectively determine the physical properties of fluids in tight reservoirs with porosity of 4-10％.Such standards provide reliably technical supports for gas/water identification,reserves estimation and productivity construction in tight reservoirs of the Sichuan Basin.关键词
四川盆地/致密砂岩/碳酸盐岩/核磁共振测井/观测模式/岩石弛豫/气水弛豫/流体性质Key words
Sichuan Basin/Tight sandstone/Carbonate/NMR logging/Activation set/Rock relaxation/Gas/water relaxation/Fluid property引用本文复制引用
张筠,吴见萌,朱国璋..致密气核磁共振测井观测模式及气水弛豫分析——以四川盆地为例[J].天然气工业,2018,38(1):49-55,7.基金项目
国家科技重大专项“大型油气田及煤层气开发”下属二级专题“四川盆地碎屑岩储层测井识别与综合评价技术研究”(编号:2008ZX05002-004-003-001). （编号:2008ZX05002-004-003-001）
