Novel tetracyclic terpanes X and Y namely C24-des-A-oleanane and C27 tetracyclic terpane were detected in crude oils and source rock extracts in Zhu 1 depression in Pearl River Mouth Basin by GC-MS analysis technology...Novel tetracyclic terpanes X and Y namely C24-des-A-oleanane and C27 tetracyclic terpane were detected in crude oils and source rock extracts in Zhu 1 depression in Pearl River Mouth Basin by GC-MS analysis technology. These compounds are similar to oleanane in the structure, and their relative abundance in m/z 191 partial mass cbromatogram has a good correlation with oleanane. Here compounds X and Y are considered to be derived from the des-A degradation of oleanoid precursor. The ratio of X/（X-I-C24） and Y/（Y-I-C24） increase with the increasing inputs of terrigenous organic matter in crude oils. Wenchang Formation middle-deep lacustrine source rocks with planktonic algae organic matter inputs and oil generating from it contain low abundance of compounds X and Y, while Enping Formation coal measures source rocks with terrigenous higher plants organic matter inputs and oil generating from it usually have higher compounds X and Y. In general when two terrigenous compounds C19 tricyclic terpane and bicadinane-T are high in crude oils, there are also a corresponding high abundant compounds X and Y. Relative abundance of compounds X and Y is closely related to the source of organic matter and it can indicate the input of terrigenous organic matter.展开更多
Based on coinjection and/or comparison with synthesized standards, a novel C_(18-23) tricy-clic terpane series with a base peak at m/z 123 on their mass spectra have been detected andconclusively identified from the b...Based on coinjection and/or comparison with synthesized standards, a novel C_(18-23) tricy-clic terpane series with a base peak at m/z 123 on their mass spectra have been detected andconclusively identified from the basal sandstone in the Upper Proterozoic Xiamaling For-mation, eastern Yanshan region, North China, and their molecular structure has been deter-mined as 13α(n- alkyl)- tricyclic terpanes. Dealing with the biomarker assemblage of the reser-voir bitumen, the source input of their organic material, two kinds of degradation effectsand origin of the novel tricyclic terpane series are approached herein.展开更多
Some problems often occur in the analysis for petroleum samples by GC-MS.When high content wax composes oil samples,the n-alkanes in saturated fraction would disturb the mass chromatograph distribution and result of b...Some problems often occur in the analysis for petroleum samples by GC-MS.When high content wax composes oil samples,the n-alkanes in saturated fraction would disturb the mass chromatograph distribution and result of biomarkers.The n-alkanes can be removed from the saturated fraction by complexation,which n-alkanes react with carbamide supersaturated in methanol solution.Nevertheless,levels of the complexation can also affect on the mass chromatograph distribution and result of biomarkers.This paper discusses these problems and measures.展开更多
One monoaromatic tricyclic diterpane and two aromatic tricyclic diterpanes were found in three low-maturity source rocks and five crude oils of the Tertiary Shahejie Formation in Shengli Oil Field. The compounds found...One monoaromatic tricyclic diterpane and two aromatic tricyclic diterpanes were found in three low-maturity source rocks and five crude oils of the Tertiary Shahejie Formation in Shengli Oil Field. The compounds found include C19H28 (m/z 145, M+ 256) ring-C monoaromatic tricyclic terpane, C17H20 (m/z 209, M+ 224) and C18H22 (m/z 223,M+ 238) rings-B,C diaromatic diterpanes. The results show that these compounds are biomarkers of immature organic matter with a stability sequence of C18H22 】 C17H20 】 C19H28. The cleavage of ring-D of pentacyclic triterpanoids, such as oleanene, hopene, fernene, ursene, in the early stage of diagenesis may be one of the origin pathways of rings-B, C diaromatic tricyclic diterpanes.展开更多
文摘Novel tetracyclic terpanes X and Y namely C24-des-A-oleanane and C27 tetracyclic terpane were detected in crude oils and source rock extracts in Zhu 1 depression in Pearl River Mouth Basin by GC-MS analysis technology. These compounds are similar to oleanane in the structure, and their relative abundance in m/z 191 partial mass cbromatogram has a good correlation with oleanane. Here compounds X and Y are considered to be derived from the des-A degradation of oleanoid precursor. The ratio of X/（X-I-C24） and Y/（Y-I-C24） increase with the increasing inputs of terrigenous organic matter in crude oils. Wenchang Formation middle-deep lacustrine source rocks with planktonic algae organic matter inputs and oil generating from it contain low abundance of compounds X and Y, while Enping Formation coal measures source rocks with terrigenous higher plants organic matter inputs and oil generating from it usually have higher compounds X and Y. In general when two terrigenous compounds C19 tricyclic terpane and bicadinane-T are high in crude oils, there are also a corresponding high abundant compounds X and Y. Relative abundance of compounds X and Y is closely related to the source of organic matter and it can indicate the input of terrigenous organic matter.
基金Project funded by the Bio- and Gas-geochemistry Laboratory, Lanzhou Institute of Geology, Academia Sinica.
文摘Based on coinjection and/or comparison with synthesized standards, a novel C_(18-23) tricy-clic terpane series with a base peak at m/z 123 on their mass spectra have been detected andconclusively identified from the basal sandstone in the Upper Proterozoic Xiamaling For-mation, eastern Yanshan region, North China, and their molecular structure has been deter-mined as 13α(n- alkyl)- tricyclic terpanes. Dealing with the biomarker assemblage of the reser-voir bitumen, the source input of their organic material, two kinds of degradation effectsand origin of the novel tricyclic terpane series are approached herein.
文摘Some problems often occur in the analysis for petroleum samples by GC-MS.When high content wax composes oil samples,the n-alkanes in saturated fraction would disturb the mass chromatograph distribution and result of biomarkers.The n-alkanes can be removed from the saturated fraction by complexation,which n-alkanes react with carbamide supersaturated in methanol solution.Nevertheless,levels of the complexation can also affect on the mass chromatograph distribution and result of biomarkers.This paper discusses these problems and measures.
文摘One monoaromatic tricyclic diterpane and two aromatic tricyclic diterpanes were found in three low-maturity source rocks and five crude oils of the Tertiary Shahejie Formation in Shengli Oil Field. The compounds found include C19H28 (m/z 145, M+ 256) ring-C monoaromatic tricyclic terpane, C17H20 (m/z 209, M+ 224) and C18H22 (m/z 223,M+ 238) rings-B,C diaromatic diterpanes. The results show that these compounds are biomarkers of immature organic matter with a stability sequence of C18H22 】 C17H20 】 C19H28. The cleavage of ring-D of pentacyclic triterpanoids, such as oleanene, hopene, fernene, ursene, in the early stage of diagenesis may be one of the origin pathways of rings-B, C diaromatic tricyclic diterpanes.
