川西新场地区须家河组断缝体气藏低阻储层气水识别  

Identifying gas and water in low-resistivity fractured-porous gas reservoirs of Xujiahe Formation,Xinchang area,western Sichuan Basin

作　　者：李阳兵 张正玉 吴晓光 LI Yangbing;ZHANG Zhengyu;WU Xiaoguang(Southwest Measurement and Control Company,Sinopec Matrix Corporation,Chengdu,Sichuan 610100,China)

机构地区：[1]中石化经纬有限公司西南测控公司,四川成都610100

出　　处：《天然气勘探与开发》2025年第2期14-25,共12页Natural Gas Exploration and Development

基　　金：中石化石油工程技术服务股份有限公司科技攻关项目(编号:SG22-19K)。

摘　　要：四川盆地西部川西坳陷新场地区三叠系上统须家河组二段气藏发育低阻裂缝—孔隙型储层,储层岩性致密、非均质性强、气水关系复杂,基于常规测井曲线以及常用的气水交会识别图版法来识别储层流体性质,存在着较大的不确定性。为了破解该区断缝体气藏低阻储层气水层识别难题,在一维核磁共振测井基础上优化设计测量模式,建立了(T_(2)、T_(1))二维核磁共振测井气水识别图版,并基于电成像测井视孔隙度频率谱技术原理,开展了低阻储层气水识别技术攻关研究。研究结果表明:①各种流体组分在二维核磁共振测井图版上具不同的分区特征,可以有效识别该区低阻裂缝—孔隙型储层可动气与可动水组分;②电成像测井具有高分辨率和高井周覆盖率,不仅可以用于分析储层孔隙结构,亦可用于低阻裂缝—孔隙度储层气水识别;③测试建议——如果低阻储层段评价为气层则进行测试,若评价为气水同层则不测试。应用结果证实,新方法的气水识别解释结论与试气结果符合率由之前的80%提升到95%左右。Fractured-porous gas reservoirs with low resistivity are extended in the second member of the Upper Triassic Xujiahe Formation(Xujiahe 2 Member),Xinchang area,western Sichuan Basin.They are characterized by tight lithology,strong heterogeneity,and complex gas-water relation,resulting in considerable uncertainty in identifying reservoir-fluid properties by using conventional logs or popular gas-water crossplots.Thus,the(T_(2)-T_(1))two-dimensional nuclear magnetic resonance(NMR)logging crossplot was created for identifying gas and water after optimizing both design and gauge on the basis of one-dimensional NMR logging.Moreover,the identification for this sort of reservoirs was discussed in the light of principles of apparent porosity frequency spectrum dependent on electrical imaging logging.Results show that(i)fluid components possess unlike zoning characteristics in the two-dimensional identification crossplot from which movable gas and water components in such reservoirs can be identified actively;(ii)with high resolution and coverage around wells,the imaging logging is available for not only pore structure analysis but gas-water identification in the low-resistivity fractured-porous reservoirs;and(iii)it is assumed the evaluated low-resistivity reservoir as a gas layer,but not as a gas-water layer.The gas-water identification interpreted from this new technology has higher coincidence with that of gas testing from previous 80%to current 95%or so.

关 键 词：气水识别 低阻裂缝—孔隙型储层 (T_(1)-T_(2))二维核磁成像谱 新场地区 四川盆地 

分 类 号：P631[天文地球—地质矿产勘探]