Abstract-Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS)

Hang Wu, Shixiang Wu, Nansheng Qiu, Jian Chang, Rima Bao, Xin Zhang, Nian Liu, Shuai Liu

http://journals.sagepub.com/doi/10.1177/0003702818761668

Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by ²³⁸U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.

Abstract-Discriminating the Mineralogical Composition in Drill Cuttings Based on Absorption Spectra in the Terahertz Range

Xinyang Miao, Hao Li, Rima Bao, Chengjing Feng, Hang Wu, Honglei Zhan, Yizhang Li, and Kun Zhao

https://www.osapublishing.org/as/abstract.cfm?uri=as-71-2-186&origin=search

Understanding the geological units of a reservoir is essential to the development and management of the resource. In this paper, drill cuttings from several depths from an oilfield were studied using terahertz time domain spectroscopy (THz-TDS). Cluster analysis (CA) and principal component analysis (PCA) were employed to classify and analyze the cuttings. The cuttings were clearly classified based on CA and PCA methods, and the results were in agreement with the lithology. Moreover, calcite and dolomite have stronger absorption of a THz pulse than any other minerals, based on an analysis of the PC1 scores. Quantitative analyses of minor minerals were also realized by building a series of linear and non-linear models between contents and PC2 scores. The results prove THz technology to be a promising means for determining reservoir lithology as well as other properties, which will be a significant supplementary method in oil fields.

Abstract-Water adsorption dynamics into active carbon probed by terahertz spectroscopy

Honglei Zhan,   Shixiang Wu,   Rima Bao,   Kun Zhao,   Lizhi Xiao,  Lina Ge and   Hongjie Shi  

RSC Adv., 2015, Accepted Manuscript

DOI: 10.1039/C4RA14730H
Received 17 Nov 2014, Accepted 12 Jan 2015
First published online 12 Jan 2015
http://pubs.rsc.org/en/content/articlelanding/2015/ra/c4ra14730h#!divAbstract


It is vital to characterize the adsorption dynamics in oil-gas reservoirs and pollution control industry. Terahertz (THz) spectroscopy was used to study the adsorption of the water molecules into active carbons. The absorbance at selected frequencies and the first principal component scores over the whole THz range were related to the corresponding time lengths. The collective tendency expressly tracked the dynamics of water adsorbed into active carbon pores. Therefore, THz technique can be used as a promising tool to monitor the adsorption issue in petroleum and environment fields.