核磁共振横向弛豫时间谱分解法识别流体性质  

A decomposition method of nuclear magnetic resonance T2 spectrum for identifying fluid properties

作　　者：钟吉彬[1,2] 阎荣辉[3] 张海涛[1,2] 冯伊涵[4] 李楠 刘行军 ZHONG Jibin;YAN Ronghui;ZHANG Haitao;FENG Yihan;LI Nan;LIU Xingjun(Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Xi'an 710018,China;National Engineering Laboratory for Exploration and Development of Low-Permeability Oil&Gas Fields,Xi'an 710018,China;PetroChina Changqing Oilfield Company,Xi'an 710018,China;Changqing Branch,China Petroleum Logging Co.,Ltd.,Xi'an 710201,China;Technology Center,China Petroleum Logging Co.,Ltd.,Xi'an 710077,China)

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,西安710018 [2]低渗透油气田勘探开发国家工程实验室,西安710018 [3]中国石油长庆油田分公司,西安710018 [4]中国石油测井有限公司长庆分公司,西安710201 [5]中国石油测井有限公司技术中心,西安710077

出　　处：《石油勘探与开发》2020年第4期691-702,共12页Petroleum Exploration and Development

基　　金：国家科技重大专项“鄂尔多斯盆地大型岩性地层油气藏勘探开发示范工程”(2016ZX05050)。

摘　　要：在核磁共振横向弛豫时间(T2)谱特征分析的基础上,利用信号分析方法分解T2谱,提出了利用T2谱分解法识别流体性质的新方法。由于T2谱在横向弛豫时间轴上满足对数正态分布的特征,采用高斯函数对T2谱进行拟合,可将T2谱分解为2~5个独立的分量谱。通过分析原油和地层水自由弛豫响应特征以及岩心油水互驱的动态响应特征,明确了各分量谱的岩石物理意义。T2谱可以分解为黏土束缚水分量谱、毛细管束缚流体分量谱、小孔隙流体分量谱和大孔隙流体分量谱。依据目标区原油性质,确定含油储集层T2分量谱峰在T2时间轴上的分布范围为165~500 ms。据此可准确识别流体性质,对于低孔隙度、低渗透率储集层中复杂油水层的识别,具有较强的适应性。Based on analysis of NMR T2 spectral characteristics,a new method for identifying fluid properties by decomposing T2 spectrum through signal analysis has been proposed.Because T2 spectrum satisfies lognormal distribution on transverse relaxation time axis,the T2 spectrum can be decomposed into 2 to 5 independent component spectra by fitting the T2 spectrum with Gauss functions.By analyzing the free relaxation response characteristics of crude oil and formation water,the dynamic response characteristics of the core mutual drive between oil and water,the petrophysical significance of each component spectrum is clarified.T2 spectrum can be decomposed into clay bound water component spectrum,capillary bound fluid component spectrum,micropores fluid component spectrum and macropores fluid component spectrum.According to the nature of crude oil in the target area,the distribution range of T2 component spectral peaks of oil-bearing reservoir is 165–500 ms on T2 time axis.This range can be used to accurately identify fluid properties.This method has high adaptability in identifying complex oil and water layers in low porosity and permeability reservoirs.

关 键 词：核磁共振 自由弛豫 横向弛豫时间(T2)谱分解法 拟合T2谱 分量谱 流体识别 

分 类 号：TE122[石油与天然气工程—油气勘探]