核磁共振频率对蚀变火山岩横向驰豫时间的影响  

Effects of Nuclear Magnetic Resonance Frequency on the Transverse Relaxation Time of Altered Volcanic Rocks

作　　者：张丽华[1] 潘保芝[1] 单刚义[1] 王敏[2] 曹玥[2] Zhang Lihua;Pan Baozhi;Shan Gangyi;Wang Min;Cao Yue(Jilin University,Changchun,Jilin 130026,China;Northeast Oil&Gas Branch of Sinopec,Changchun,Jilin 130026,China)

机构地区：[1]吉林大学,吉林长春130026 [2]中国石化东北油气分公司,吉林长春130026

出　　处：《特种油气藏》2023年第2期20-25,70,共7页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金面上项目“IFCD油页岩原位转化过程流-热-应力-化学耦合数值模拟研究”(NSFC 42072323)。

摘　　要：为了研究频率对蚀变火山岩横向驰豫时间T_(2)的影响,选取了龙凤山地区的蚀变火山岩岩样,进行了X射线衍射全岩和黏土分析,对其中代表性样品进行了2 MHz和12 MHz的核磁共振测量。研究表明:蚀变的黏土矿物以绿泥石为主;随着核磁共振频率的增大,T_(2)谱有向左偏移的趋势,这种偏移会导致对孔隙结构的错误认识,可以通过拟合公式进行偏移校正。该校正方法可以指导其他频率核磁仪器测量结果广泛地应用。In order to study the effect of frequency on the transverse chirality time T_(2)of altered volcanic rocks,the altered volcanic rock samples from Longfeng Mountain area were selected for X-ray diffraction whole-rock and clay analysis,and NMR measurements at 2 MHz and 12 MHz were performed on representative samples.The results of the study show that the altered clay minerals are dominated by chlorite;the T_(2)spectrum tends to shift to the left as the NMR frequency increases;this shift can lead to a false perception of the pore structure and can be corrected for the shift by the fitting formula.This correction method can guide the application of NMR instrument measurements at other frequencies in wells.

关 键 词：蚀变火山岩 核磁共振 驰豫时间 磁场梯度 绿泥石 

分 类 号：TE357[石油与天然气工程—油气田开发工程]