随钻核磁共振测井T_(2)水谱重构方法与低电阻率油层识别  

Reconstruction Method of the T_(2) Water Spectrum and Identification of Low Resistivity Oil Layers with NMR Logging While Drilling

作　　者：朱猛 崔云江 许赛男 张冲[2] 张占松[2] 杨旺旺 ZHU Meng;CUI Yunjiang;XU Sainan;ZHANG Chong;ZHANG Zhansong;YANG Wangwang(Tianjin Branch, China National Offshore Oil Corporation, Tianjin 300459, China;College of Geophysics and Petroleum Resources, Yangtze University, Wuhan, Hubei 430100, China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459 [2]长江大学地球物理与石油资源学院,湖北武汉430100

出　　处：《测井技术》2022年第3期340-345,共6页Well Logging Technology

基　　金：中海石油(中国)有限公司重大科技专项“渤海油田稳产3000万吨,上产4000万吨关键技术研究课题1:渤海油田强化水驱及增产挖潜技术”(CNOOC-KJ 135 ZDXM 36 TJ01TJ-GD 2020-02)。

摘　　要：以渤海A油田馆陶组储层为例,分析了不同流体性质储层的随钻核磁共振测井响应特征。轻质油储层的T2谱呈现宽缓的丘陵状,且会显示拖尾现象;水层的T_(2)谱呈现陡尖的山峰状。在此基础上,提出了一种基于三维网格技术重构水谱识别低电阻率油层的方法。该方法选取不同孔隙结构的水层段随钻核磁共振测井T_(2)谱,以随钻自然伽马、随钻核磁共振总孔隙度和随钻核磁共振渗透率作为三维网格的坐标轴,构建了三维水谱库,然后应用构建的水谱与实测谱的差异特征进行低电阻率油层的判别。研究表明,与二维网格技术相比,三维网格技术通过增加一个维度使得每一个被划分的网格存储单元更加精细,其构建的水谱更为合理。多口井的验证表明,该方法对于研究区岩性细、泥质含量高的低电阻率油层识别准确率高,可以推广应用。Take the Bohai A oilfield of the Guantao formation as an example,the response characteristics of NMR logging while drilling in reservoirs with different fluid properties are analyzed.The results indicate that,for the light oil reservoirs,the T_(2) spectrum of NMR logging while drilling presents a broad and gentle hilly shape,and will show training phenomenon.For the water zone,the T2 spectrum of NMR logging while drilling shows a steep peak shape.On this basis,a method based on three-dimensional grid technology to reconstruct water spectrum to identify low resistivity oillayers is proposed.In this method,the T_(2) spectrum of NMR logging while drilling in water interval with different pore structure is selected,and the natural gamma ray while drilling,total porosity and permeability of NMR while drilling are used as coordinate axes of three-dimensional grid,then a library of 3D water spectra is constructed.The difference between the constructed water spectrum and the measured spectrum is used to distinguish low resistivity oil layers.The research shows that,compared with the two-dimensional grid technology,the three-dimensional grid technology can make each grid storage unit more refined by adding one dimension,and it builds a more rational water spectrum.This method has been verified by several wells and has high identification accuracy for the low resistivity oil layers with fine lithology and high mud content in the study area,which can be popularized and applied.

关 键 词：低电阻率储层 水谱重构 三维网格技术 随钻核磁共振测井 流体识别 

分 类 号：P631.84[天文地球—地质矿产勘探]