测井技术2025，Vol.49Issue(5)：734-747,14.DOI:10.16489/j.issn.1004-1338.2025.05.009
西湖凹陷NX区平湖组碎屑岩单井相精细识别与应用
Fine Identification and Application of Single Well Facies of Pinghu Formation Clastic Rocks in NX Area of Xihu Sag
摘要
Abstract
To precisely identify single well facies(microfacies)of clastic rocks in the Pinghu formation of NX area,Xihu sag,understand their internal characteristics,and support reservoir evaluation and prediction of favorable reservoirs,phase marker information of different microfacies is extracted using electrical imaging logging images,and 6 types of microfacies are classified;lithological,physical,and electrical characteristics of different microfacies are analyzed,electrical imaging logging images are compared with logging curves,and a set of microfacies curve recognition models applicable to the area are summarized;multi-well microfacies identification and well-connecting analysis based on the curve models are carried out,and a vertical evolution sedimentary model is established.The research results show that:①The upper member of the Pinghu formation develops tidal-controlled delta facies with microfacies including underwater distributary channels and interdistributary bays,and the middle member develops tidal flat facies with microfacies including tidal channels,intertidal sand flats,intertidal mud flats,and sand-mud mixed flats.②Underwater distributary channels and tidal channels are dominated by fine sandstone,being dominant microfacies in terms of physical properties,with average porosities of 16.3%and 13.6%,and average permeabilities of 80.0 mD and 46.8 mD,respectively.③Logging identification features are significant.resistivity of tidal flat facies fluctuates significantly compared with tidal-controlled delta facies,GR values of sand-mud mixed flats range from 90～130 API with frequent fluctuations;logging curves of underwater distributary channels(thickness 20～40 m)and tidal channels(thickness 10～20 m)show low GR box characteristics;coal seams have low GR,high AC,and high Rt value characteristics,concentrated in intertidal mud flats and sand-mud mixed flats.④A vertical evolution sedimentary model transitioning from tidal flat facies to tidal-controlled delta facies from bottom to top is established.It is concluded that single well facies identification can be realized using conventional logging curve features,basically replacing high-cost electrical imaging logging;the clarified microfacies distribution,characteristics,and vertical evolution model provide a basis for predicting favorable underwater distributary channel and tidal channel microfacies on the plane.关键词
西湖凹陷/平湖组/相标志/电成像/沉积微相/测井曲线形态/连井剖面/沉积模式Key words
Xihu sag/Pinghu formation/facies marker/electrical imaging/sedimentary microfacies/logging curve morphology/well-tie section/sedimentary model分类
天文与地球科学引用本文复制引用
张瑞湘,闫建平,闫华,耿斌,王军,邱小雪..西湖凹陷NX区平湖组碎屑岩单井相精细识别与应用[J].测井技术,2025,49(5):734-747,14.基金项目
国家科技重大专项课题"致密油有效储层表征技术"(2017ZX05072-002) （2017ZX05072-002）
国家自然科学基金项目"低电阻率页岩气储层:成因机制差异及含气饱和度模型研究"(42372177) （42372177）
