低渗透率储层核磁共振测井环境分析与T_(2)谱油层识别方法  

NMR Logging Environment Analysis and T_(2)Spectrum Oil Layer Identification Method in Low Permeability Reservoir

作　　者：曹志锋 令狐松 孟鑫[2] 白鹏 孙正龙[2] 张凯 CAO Zhifeng;LINGHU Song;MENG Xin;BAI Peng;SUN Zhenglong;ZHANG Kai(Xinjiang Branch,China National Logging Corporation,Karamay,Xinjiang 834000,China;Development company,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China;Exploration Division,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石油集团测井有限公司新疆分公司,新疆克拉玛依834000 [2]中国石油新疆油田公司开发公司,新疆克拉玛依834000 [3]中国石油新疆油田公司勘探事业部,新疆克拉玛依834000

出　　处：《测井技术》2024年第3期370-379,共10页Well Logging Technology

基　　金：中国石油天然气集团有限公司攻关性应用性专项“砾岩油藏规模增储上产与提高采收率关键技术研究”(2023ZZ23)。

摘　　要：准噶尔盆地玛湖凹陷发育低渗透率砾岩储层,不同地层的核磁共振T_(2)谱对这些储层流体的识别结果存在较大差异。基于地质、钻井、测井、试油等资料,开展了此类地层测井环境、核磁共振实验和测井响应特征机理的研究。结果表明:研究区钻井改善了近井筒储层孔隙结构,从近井筒到原状地层依次发育破碎带、微细裂缝带、原状地层;在负压钻井环境下发生油气侵出,油气侵出特性径向上可分为油气富集带(油环)、油气侵出带、原状地层,厘清了核磁共振测井响应特征机理;利用模块式地层动态测试仪(Modular Formation Dynamics Tester,MDT)验证了井壁油环的存在。基于岩心饱水、饱油及饱水离心的核磁共振T_(2)谱体积弛豫谱与地层原油的核磁共振T_(2)谱长弛豫时间峰一致,确定了核磁共振T_(2)谱100 ms识别油层和水层的标准。该方法在储层流体识别方面取得了显著效果,研究结果为利用核磁共振T_(2)谱识别复杂储层流体提供了借鉴。Low permeability conglomerate reservoirs are developed in Mahu sag,Junggar basin,and the nuclear magnetic resonance(NMR)T_(2)spectra of different formations have great differences in the identification results of these reservoir fluids.Based on geological,drilling,logging and oil testing data,the logging environment,NMR experiments and logging response characteristics of such formations have been studied.The results show that the pore structure of the near-wellbore reservoir is improved by drilling in the study area,and the broken zone,microfracture zone and undisturbed strata are developed successively from the near-wellbore to the undisturbed strata.Oil and gas invasion occurs in the negative pressure drilling environment.Oil and gas invasion can be divided into oil and gas enrichment zone(oil ring),oil and gas invasion zone and undisturbed strata in the radial direction,and the response mechanism of NMR logging is clarified.The existence of oil ring is verified by using the modular formation dynamics tester.The NMR T_(2)spectral volume relaxation spectra of core saturated with water,saturated with oil and saturated with water centrifugation are consistent with the NMR T_(2)spectral long relaxation time peak of formation crude oil,and the standard of NMR T_(2)spectra 100 ms is determined to identify oil and water layers.This method has achieved remarkable results in reservoir fluid identification,the results provide a reference for the identification of complex reservoir fluids by NMR T_(2)spectroscopy.

关 键 词：低渗透率砾岩储层 核磁共振测井 油气侵出特性 岩石物理实验 流体识别 准噶尔盆地玛湖凹陷 

分 类 号：P631.84[天文地球—地质矿产勘探]