Molecular And Carbon Isotopic Composition In Organic Inclusion: Methodology And Application

Oils trapped in organic inclusion represent the palaeo-oils which would not been changed due to subsequent secondary alterations. Analysis of organic inclusion composition can make great contribution to the study of oil-source correlation, migration, charge history and secondary alterations. Thesis are mainly composed of two parts: work done in domestic lab which includes developing the analysis method of organic inclusion composition and its application and work done in CSIRO Petroleum lab in Australia which includes learning the Molecular Composition of Inclusion (MCI) techniques and analyzing the samples from Lunnan region, Tarim Basin using the MCI technique. So far many studies have been examined for analyzing C₁₅₊ hydrocarbons in organic inclusions but few studies put emphasis on gas in inclusions, especially the gas isotope analysis. In this work, new method was challenged. New crushing device was designed based on CSIRO's crusher. Gas composition, gas carbon isotope and high molecular hydrocarbon released from organic inclusions in the same aliquot sample can be analyzed using the new crushing device. It is practicable to analyze the gas based on the seal experiment. Excellent system blank, reproducibility and recovery ratio are obtained in this experiment as well.Gas and higher molecular weight hydrocarbon from organic inclusions in calcite vein in Jurong region, Jiangsu were analyzed using domestic method. Geochemical characteristics of hydrocarbon released by organic inclusions show multiple charge history in Jurong area. Two types of organic inclusion existed in Triassic reservoir in well Rong2: one type of organic inclusions contain more higher carbon number n-alkanes with maxima at nC₂₂ which show hydrocarbon trapped in inclusion were slightly biodegraded with lower molecular carbon number n-alkanes removed; another type of organic inclusions contain bimodal n-alkane distribution, probably showing hydrocarbons trapped in organic inclusions are mixture of biodegraded oils and normal oils. Light oils in present reservoir are different from these two types of organic inclusions. It's speculated that earlier charging episode was damaged and light oils in present reservoir were mainly from the later charging episode. Seen from the preliminary data, one type of organic inclusion existed in well Rong3. Hydrocarbon and light oils in present reservoir in well Rong3 were suspected from different charging episodes.Composition and methane carbon isotope of gas released by organic inclusion in Upper Paleozoic reservoir, Ordos Basin were analyzed using domestic method. Through comparing the composition and methane carbon isotope of inclusion and coal-formed gas, it's concluded that composition and carbon isotope of gas were influenced by primary migration which was defined...