Novel C-26 tetracyclic degraded bicadinanes in oil sands from the Haitoubei-Maichen Sag of the Beibuwan Basin, South China Sea

作者：Bao Jianping^*; Zhu Cuishan; Liu Yurui; Wang Wenjun; Liu Hongyu

来源：Organic Geochemistry, 2013, 58: 89-95.

DOI：10.1016/j.orggeochem.2013.02.014

Three C-26 tetracyclic terpanes were detected in the saturated hydrocarbon fractions of oil sand samples especially rich in bicadinanes W, T and R from the Oligocene Huizhou Formation in the XW-1 well in the Haitoubei-Maichen Sag of the Beibuwan Basin. Their mass spectra show molecular ions of the three tetracyclic terpanes at m/z 358, and their key fragment ions at m/z 343 (M+.-15) and m/z 315 due to loss of an isopropyl group. These characteristics are very similar to that of C-30 cis-cis-trans (W) and trans-trans-trans (T) bicadinanes. In addition, the relative abundances of the C-26 tetracyclic terpanes show an excellent positive correlation with the C-30 bicadinanes W and T in 27 oil sand samples. Therefore, the three C-26 tetracyclic terpanes are tentatively identified as degraded bicadinanes, which like bicadinanes, may indicate input from dammar resins and can be used to discriminate the origin of crude oils.

• 出版日期2013-5
• 单位长江大学