高校地质学报2017，Vol.23Issue(4)：688-696,9.DOI:10.16108/j.issn1006-7493.2017099
东营凹陷沙河街组Es3/Es4烃源岩热解特征及生烃差异研究
Characteristics of Rock-Eval Pyrolysis and Hydrocarbon Generation for Source Rocks of Eocene Shahejie Third and Fourth Members, Dongying depression
摘要
Abstract
To investigate the characteristics and differences of hydrocarbon pyrolysis and generation for source rocks of the Eocene Shahejie third (Es3) and fourth (Es4) members in the Dongying depression, source rock samples were collected to perform Rock-Eval pyrolysis. Results show that the source rocks from lower Es3 and upper Es4 share similar maturities. Conventional pyrolysis parameters including TOC, kerogen type and S1+S2 suggest that the lower Es3 source rocks have better qualities than the upper Es4 ones. The mean value of free hydrocarbon (S1) and the ratio of S1/PC of the upper Es4 samples is higher than those of the lower Es3 samples. In constrast, the pyrolytic hydrocarbon (S2) and S2/PC vaules have opposite results. Combined with previous studies on the relations between organic matter (OM) occurrences and pyrolysis parameters, the higher S2 value of lower Es3 source rocks as well as the dominance of I/S in terms of mineralogy suggests a higher contribution of intercalated OM. The saline sedimentary environment of Es4 source rocks is conducive to the alteration from smectite to illite. This mineralogical alteration causes expulsion of most OM that previously hosted in smectite layers. Under similar geological conditions, these unprotected OM can be converted to hydrocarbon more easily, leading to a higher S1 value of the upper Es3 source rocks than that of the lower Es4 source rocks. Thus, the differences in OM occurrences and sedimentary environments account for the discrepancy between pyrolysis parameters and exploration practice. A detailed study on the relationship between pyrolysis parameters and OM occurrences could provide insights into the nature of OM in source rock as well as their potential for hydrocarbon generation.关键词
东营凹陷/沙三下/沙四上/烃源岩/有机质赋存态/热解特征/生烃差异Key words
Dongying depression/the lower Es3 and upper Es4/source rock/organic matter occurrence/Rock-Eval pyrolysis/hydrocarbon generation分类
天文与地球科学引用本文复制引用
巢前,蔡进功,周祺盛,刘伟新,张彩明,蒋启贵..东营凹陷沙河街组Es3/Es4烃源岩热解特征及生烃差异研究[J].高校地质学报,2017,23(4):688-696,9.基金项目
中国自然科学基金(41672115 （）
41372130) （）
国家油气重大专项(2016ZX05006001-003)联合资助 （2016ZX05006001-003）
