中国南方海相页岩储层可动流体及 T2截止值核磁共振研究  

NMR research of movable fluid and T_2 cutoff of marine shale in South China

作　　者：周尚文[1,2,3] 刘洪林[1,2,3] 闫刚[1,2,3] 薛华庆[1,2,3] 郭伟[1,2,3] 

机构地区：[1]畅中国石油勘探开发研究院廊坊分院,河北廊坊065007 [2]中国石油非常规油气重点实验室,河北廊坊065007 [3]国家能源页岩气研发( 实验)中心,河北廊坊065007

出　　处：《石油与天然气地质》2016年第4期612-616,共5页Oil & Gas Geology

基　　金：国家重点基础研究发展计划(973计划)项目(2013CB2281);国家科技重大专项(2011ZX05018)

摘　　要：为了分析中国南方海相页岩气储层的可动流体及T2截止值特征，结合低场核磁共振和高速离心实验进行了页岩可动流体测试。实验结果表明：页岩饱和水状态和束缚水状态的建立至关重要，中国南方海相页岩建立饱和水状态的最佳压力为12 MPa，建立束缚水状态的最佳离心力2.76 MPa。其可动流体T2截止值为1.07～3.22 ms，平均值为1.8 ms，明显小于致密砂岩的T2截止值。使用经验值13 ms来进行页岩可动流体的计算将会产生很大误差。结合饱和水状态和束缚水状态的核磁共振T2谱，得到可动流体饱和度为23.19％～30.84％，平均值为27.28％，束缚水饱和度高，超低含水饱和度现象明显。将核磁共振T2谱转换成孔径分布，得到页岩孔隙半径主要分布在20～200 nm。Low field Nuclear Magnetic Resonance was combined with high speed centrifugal experiments to study movable fluids and T2 cutoff values of marine shale in South China.The experiments reveal the importance of establishing water saturated state and irreducible water state for the calculation of movable fluids.For marine shale from South China,the optimum pressure for establishing water saturated state is 12 MPa,and the optimum centrifugal force for establishing irre-ducible water state is 2.76 MPa.The T2 cutoff values range between 1.07 ms and 3.22 ms,averaging at 1.8 ms,signifi-cantly less than that of tight sandstone.Therefore,using empirical value （13 ms） for the calculation of movable fluids may result in great error.To deal with the problem,we integrated the T2 spectrums of both saturated water state and irreducible water state to calculate movable fluid saturation.The result ranges between 23.19% and 30.84% （ averaging at 27.28%） ,indicating high irreducible water saturation and ultra-low water saturation.we also converted the NMR T2 spectrum into pore size distribution,revealing the pore radius of shale to be within 20 and 200 nm range.

关 键 词：T2 截止值 孔隙半径 核磁共振 可动流体 页岩气 海相页岩 中国南方 

分 类 号：TE135[石油与天然气工程—油气勘探]