基于低场核磁共振的深层-中浅层页岩优质储层有机-无机孔隙系统差异性对比表征  

Comparative characterization of differences in organic inorganic pore systems of high-quality shale reservoirs from deep to middle-to-shallow layers based on low field NMR

作　　者：刘丹丹 赵迪斐[2] 何甲文泽[1,2] 胡鑫蒙 张磊 魏源[3] 邹筱瑜 焦伟伟 郭英海 LIU Dandan;ZHAO Difei;HE Jiawenze;HU Xinmeng;ZHANG Lei;WEI Yuan;ZOU Xiaoyu;JIAO Weiwei;GUO Yinghai(Sun Yueqi Honors College,China University of Mining and Technology,Jiangsu Xuzhou 221116,China;Artificial Intelligence Research Institute,China University of Mining and Technology,Jiangsu Xuzhou,221116,China;School of Earth Sciences,Nanjing University,Nanjing 210000,China;School of Mechanical and Electrical Engineering,China University of Mining and Technology,Jiangsu Xuzhou 221116,China;School of Architecture and Engineering,Chongqing Vocational and Technical College of Industry,Chongqing 401120,China;School of Resources and Geosciences,China University of Mining and Technology,Jiangsu Xuzhou 221116,China)

机构地区：[1]中国矿业大学孙越崎学院,江苏徐州221116 [2]中国矿业大学人工智能研究院,江苏徐州221116 [3]南京大学地球科学与工程学院,南京210000 [4]中国矿业大学机电学院,江苏徐州221116 [5]重庆工业职业技术学院建筑工程学院,重庆401120 [6]中国矿业大学资源与地球科学学院,江苏徐州221116

出　　处：《非常规油气》2025年第2期33-40,共8页Unconventional Oil & Gas

基　　金：国家自然科学基金项目“海相页岩储层纳米级孔隙精细表征与定量评价”(41772130);江苏省自然科学基金青年科学基金项目“超高精度3D-4D孔隙精细结构及微观流体行为机理表征技术体系”(SBK2021045820);江苏省大学生科研训练省级创新项目“基于图像智能处理与多尺度分形的页岩储层纳米级储集空间量化表征”(202310290234Y);煤层气资源与成藏过程教育部重点实验室(中国矿业大学)开放基金项目“非常规储层非均质性及其地质意义”(2015-007)。

摘　　要：页岩储层孔隙系统包含有机孔隙和无机孔隙,两者在气体吸附特征和润湿性上存在显著差异。深化对有机-无机孔隙系统差异化发育特征的认识,可以为优质储层预测提供科学依据。低场核磁共振在页岩孔隙表征中具有无破坏性以及表征孔径范围广的优点。以渝西地区和渝东南地区龙马溪组页岩优质储层样品为例,基于页岩微观组分亲水-亲油特性差异,通过低场核磁共振对代表性样品进行饱和油或饱和水条件下的孔隙结构测试和对比,并对有机孔隙和无机孔隙进行表征。结果表明,龙马溪组底部页岩样品有机孔孔径分布在2~50 nm和0.5~10.0μm;无机孔孔径主要分布在2.5~500.0 nm,其相对有机孔隙孔径更大,发育孔径范围更广。深层页岩样品有机纳米孔隙和有机质内部孔隙发育程度较高,孔隙连通性较好;中浅层页岩样品孔隙系统中过渡性孔隙群组发育程度较低,缺乏页岩气微观运移的孔隙通道。该研究定性和半定量地表征了深层-中浅层优质页岩储层有机孔和无机孔分布特征,为页岩孔隙系统评价与储层对比提供了指导。The pore system of shale reservoirs includes organic and inorganic pores,with significant differences in gas adsorption characteristics and wettability.Deepening the understanding of the differentiated development characteristics of organic and inorganic pore systems could provide the scientific basis for predicting high-quality reservoirs.The low field NMR has the advantages of non-destructive characteristics and extensive ranges of pore size in shale pore characterization.High-quality shale samples from Longmaxi Formation in the western and southeastern regions of Chongqing were selected as examples in this study.Based on the differences in hydrophilic-hydrophobic properties of shale micro components,the low field NMR was used to test and compare the pore structure of representative samples under saturated-water and saturated-oil conditions and to characterize organic and inorganic pores.The results indicate that the organic pore size distribution of shale samples from the bottom of Longmaxi Formation is between 2~50 nm and 0.5~10.0 μm,respectively.The inorganic pore sizes range from 2.5 nm to 500.0 nm,with larger pore sizes and a wider range than organic pores.Organic nanopores and internal pores in organic matter are significantly developed in deep shale samples,and the pore connectivity is good.The transitional pore groups in the pore system of middle-to-shallow shale samples are relatively undeveloped,and there is a lack of pore channels for the micro-migration of shale gas.This study qualitatively and semi-quantitatively characterizes the distribution characteristics of organic and inorganic pores in deep and middle-shallow high-quality shale reservoirs,which guides shale pore system evaluation and reservoir comparison.

关 键 词：深层页岩 龙马溪组页岩 核磁共振 孔隙结构 优质储层 有机孔隙 无机孔隙 

分 类 号：TE122[石油与天然气工程—油气勘探]