基于核磁共振T_2谱分布的储层岩石孔隙分形结构研究  

Fractal Characteristics of Reservoir Rock Pore Structure Based on NMR T_2 Distribution

作　　者：张超谟[1] 陈振标[1] 张占松[1] 李军[1] 令狐松 孙宝佃 

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),湖北荆州434023 [2]中国石油集团测井有限公司技术中心,陕西西安710021

出　　处：《石油天然气学报》2007年第4期80-86,共7页Journal of Oil and Gas Technology

基　　金：国家"863"项目(2006AA06Z220);中国石油天然气集团公司应用基础研究项目(06A30102)

摘　　要：结合前人在储层岩石分形结构与利用核磁共振(NMR)T2谱分布评价孔隙结构这两方面的研究成果,推导出NMRT2值的分形几何表达式,建立了利用NMRT2谱进行储层孔隙分形结构研究的方法。该方法较常规的岩石孔隙分形结构研究方法具有快速、无损坏等特点,且进一步拓展了核磁共振资料的应用。应用此方法对A地区X井的10块岩心进行了分形结构判断与分形维数的求取,其判断结果与毛管压力判断结果一致,但其分形维数普遍低于应用毛管压力法求得的分形维数,此差异是由于二者所反映的孔喉空间不同造成的。研究结果同时表明:利用NMRT2谱分布求取的分形维数可以较好地表征岩石物性,可为储层特征研究、储层分类等提供一定的参考依据。Fractal geometry expression of NMR T_2 value was derived based on the predecessor researches in the fractal characteristics of sandstone pore structure and the relation between capillary pressure and NMR T_2 value.A method for studying the pore structure fractal characteristics was developed by using the distribution of NMR T_2.compared with conventional methods,it has some advantages,such as fast,no damage on sample and so on,and it expands the application of NMR data as well.Judging the fractal characteristics and calculating the fractal dimension of 10 core samples were carried out in Well X of Area A by using this method.The results of judgment were consistent with that of capillary pressure data,but the calculated fractal dimensions are smaller than those calculated with capillary pressure data.The difference is caused by the difference of pore structure mentioned above.The result also indicates that the fractal dimension obtained with T2 can be used to characterize the rock physical properties and provide reference for reservoir characteristic study and its identification.

关 键 词：核磁共振(NMR) 孔隙结构 分形几何 T2谱分布 毛管压力 岩石物性 

分 类 号：P631.2[天文地球—地质矿产勘探]