摘要
核磁共振直接探测孔隙流体信息,是评价页岩油含油性的重要测井系列,但由于有机孔隙中沥青、束缚油、可动油与无机孔隙中束缚水的横向弛豫时间T2基本重叠,难以利用一维T2谱有效区分这些信息。通过流体组分核磁特性分析,发现不同流体纵向弛豫时间T1差异较大,特别是通过T1/T2能够有效评价页岩油含油信息,在此基础上提出了一种4状态下T1-T2二维核磁共振页岩油含油性检测方法,即4状态法。实践结果表明,各种流体组分在T1-T2二维谱图上具有不同的分布范围,通过对T1-T2谱图进行数据分割,得到各种流体组分信息。利用该模型对歧口凹陷沙三段页岩油进行评价并进行水平井部署,实施后获得20 t/d以上的高产,验证了T1-T2二维核磁共振页岩油储集层含油性检测方法的准确性。
The direct detection of pore fluid information by NMR is an important logging suite to evaluate oil-bearing property of shale oil.Since the transverse relaxation time T2 of asphalt,irreducible oil and movable oil in organic pores basically overlaps with that of bound water in inorganic pores,it is difficult to distinguish these information effectively by one-dimensional T2 spectrum.Through the analysis of the fluid compositions′nuclear magnetic characteristics,it is found that the longitudinal relaxation time T1 of different fluids varies greatly,especially the oil-bearing information of shale oil can be effectively evaluated by T1/T2.On this basis,a 4-state T1-T2 two-dimensional NMR method is proposed to detect the oil-bearing property of shale oil.The results show that various fluid compositions have different distribution ranges on T1-T2 two-dimensional spectrogram.By data partitioning of the T1-T2 spectrogram,various fluid composition information is obtained.The model was used to evaluate the shale oil in the Third Member of Shahejie Formation in Qikou sag and horizontal wells were deployed.The high yield of 20 t/d is obtained after implementation,and the accuracy of oil-bearing property detection of T1-T2 two-dimensional NMR shale oil reservoir is verified.
作者
丁娱娇
李俊国
朱伟峰
刘爱平
吕芳芳
钟巍
DING Yujiao;LI Junguo;ZHU Weifeng;LIU Aiping;LYU Fangfang;ZHONG Wei(Exploration and Development Institute of PetroChina Dagang Oilfield Company, Tianjin 300280,China;Resource Evaluation Division of PetroChina Dagang Oilfield Company, Tianjin 300280,China)
出处
《录井工程》
2020年第S01期48-53,共6页
Mud Logging Engineering
