核磁共振测井仪在南海浅层的测量分析

Analysis of NMR Logging Tool in Offshore Shallow Survey

南海浅层疏松砂泥岩储层岩性细,常规测井技术区分砂岩与泥岩存在困难,不利于储层划分。核磁共振测井能充分发挥其受岩性影响小且可进行孔隙结构精细评价的优势,提供丰富的地层信息。首先,阐述核磁共振测井仪器的结构、测量功能及耐温耐压性能。其次,介绍核磁共振测井的2种测量方式,并对2种方式的采集原理及分析方法进行对比。最后,分析中海油田服务股份有限公司研制的二维核磁共振测井仪器在南海浅层的实测案例。案例中核磁共振测井资料比常规测井资料能更有效地判别泥质砂岩层与泥岩层的差异性,为有效储层的划分提供依据。此外利用二维核磁共振采集模式对案例中重点储层进行同一纵向深度点的不同横向切片深度分析,可实现储层流体的有效识别。

The lithology of shallow loose sand shale reservoir in the South China Sea is fine.It is difficult to distinguish sandstone and mudstone by conventional logging technology,which is not conducive to reservoir division.NMR logging can give full play to its advantages of being less affected by lithology and fine evaluation of pore structure,and provide rich formation information.Firstly,the structure,measurement function,temperature and pressure resistance of NMR logging tool are described.Secondly,two measurement methods of NMR logging are introduced,and the acquisition principles and analysis methods of the two methods are compared.Finally,the measured case of COSL’s two-dimensional NMR logging tool in the shallow layer of the South China Sea is analyzed.In the case,NMR logging data can more effectively distinguish the difference between argillaceous sandstone and mudstone than conventional logging data,and provide a strong basis for effective reservoir division.In addition,the two-dimensional NMR acquisition mode is used to analyze the depth of different transverse slices at the same longitudinal depth point of the key reservoir in the case,which can realize the effective identification of reservoir fluid.