Characterizing the maturity of highly evolved organic matter based on aromatic hydrocarbons and optimization with pyrobitumen reflectance and Raman spectral parameters  

作　　者：Zhaoxi ZUO Jian CAO Wenxuan HU Chunhua SHI Xiaolin WANG Suping YAO Bing LUO 

机构地区：[1]State Key Laboratory for Mineral Deposits Research,School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China [2]Chongqing Gas Field of PetroChina Southwest Oil and Gas Field Company,Chongqing 401120,China

出　　处：《Science China Earth Sciences》2022年第12期2335-2357,共23页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42230808 and 41830425).

摘　　要：Maturity evaluation of highly evolved organic matter is an important problem in oil and gas geochemistry,because conventional organic geochemical proxies are not applicable due to hydrocarbon generation and expulsion.In this study,we investigated the pyrobitumen in the reservoirs of the Sinian Dengying Formation in the Sichuan Basin,China.We focused on aromatic hydrocarbon biomarkers,and the calibration and application of aromatic maturity proxies using pyrobitumen reflectance and Raman spectral parameters.Our results show that only the thiophene compounds are effective maturity indicators,such as MDR(4-/1-MDBT),MDR′(4-MDBT/(1-MDBT+4-MDBT)),MDR1(1-MDBT/DBT),4,6-/(1,4+1,6)-DMDBT,(2,6+3,6)-/(1,4+1,6)-DMDBT,and[2,1]BNT/([2,1]BNT+[1,2]BNT),as these are largely independent of the optical anisotropy of pyrobitumen.The condensation and incorporation of thiophene compounds can lead to an increase in the reflectance of pyrobitumen,which means the thiophene compound parameters are positively or negatively correlated with pyrobitumen reflectance.New potential maturity parameters were proposed,including DMDBTs/MDBTs,TeMDBTs/(DBT+MDBTs+DMDBTs+TMDBTs+TeMDBTs),1-MDBT/MDBTs,and[2,1]BNT/BNTs.This method and these parameters are universally applicable to maturity characterization,especially in rocks that lack vitrinite,contain strongly anisotropic organic matter,and have high contents of thiophene compounds.

关 键 词：Maturity characterization of high-evolution organic matter Reservoir pyrobitumen Optical texture Dengying Formation Sichuan Basin 

分 类 号：TE31[石油与天然气工程—油气田开发工程] O657.37[理学—分析化学]