Study on Correlation Between Total Organic Carbon, Soluble Hydrocarbon, Pyrolytic Hydrocarbon Content and Spectral Index in Source Rocks
YE Fa-wang1, WANG Jian-gang1, QIU Jun-ting1, ZHANG Chuan1, YU Xin-qi2, LIU Xiu2
1. National Key Laboratory of Science and Technology on Remote Sensing Information and Image Analysis, Beijing Research Institute of Uranium Geology, Beijing 100029, China
2. School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
Abstract：The total organic carbon content (TOC), soluble hydrocarbon content (S1) and pyrolysis hydrocarbon content (S2) of source rocks are important indicators for the study and evaluation of source rocks. In the past, they were mainly obtained through laboratory analysis, and the timeliness could not be guaranteed. In order to explore the feasibility of rapid measurement of these indicators in the field, this study collected 10 hydrocarbon source rock samples from the qilakum block in uzbekistan, and measured the visible light-near infrared-short wave infrared (vis-nir-swir) reflectance spectrum and content parameters of TOC, S1 and S2 of the samples respectively by using the ground ASD spectrometer and carbon and sulfur analyzer. The first derivative and second derivative of the reflectance spectrum of the sample were obtained by spectral fitting differential. The correlation between these data and the contents of TOC, S1 and S2 was studied by using linear regression equation fitting and statistical analysis of fitting results. The results show that S1 content of source rocks was correlated with the original spectrum, the first derivative of the spectrum and the second derivative of the spectrum in 1 973, 511 and 239 bands, respectively. The absolute value of the correlation coefficient was 0.612, 0.823 and 0.889, respectively. The correlation degree was weak, strong and strong, respectively. S2 content in source rocks was correlated with 2, 144 and 205 bands of the original spectrum, the first derivative of the spectrum and the second derivative, respectively. The absolute value of the correlation coefficient was 0.561, 0.867 and 0.926, respectively. The correlation degree was weak, strong and extremely strong, respectively. There was no correlation between the TOC content of source rocks and the original spectrum, and it was correlated with 18 and 180 bands of the first and second derivatives of the spectrum, respectively. The absolute value of the correlation coefficient was 0.882 and 0.879, respectively. The correlations were extremely strong. In addition, the best fitting degree of S1 content and the second derivative of spectrum at the band of 2 012 nm was 0.790. The best fitting degree of S2 content and the second derivative of spectrum at the band of 363 nm was 0.858. The best fitting degree of TOC content and the first derivative of spectrum at the band of 2 480 nm was 0.777. This study lays an important foundation for in-situ detection of source rocks in the field.
叶发旺，王建刚，邱骏挺，张 川，余心起，刘 秀. 烃源岩可溶烃、热解烃、总有机碳含量与光谱指数相关性研究[J]. 光谱学与光谱分析, 2020, 40(04): 1001-1006.
YE Fa-wang, WANG Jian-gang, QIU Jun-ting, ZHANG Chuan, YU Xin-qi, LIU Xiu. Study on Correlation Between Total Organic Carbon, Soluble Hydrocarbon, Pyrolytic Hydrocarbon Content and Spectral Index in Source Rocks. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(04): 1001-1006.
