Based on Common Inverted Microscope to Measure UV-VIS Spectra of Single Oil-Gas Inclusions and Colour Analysis

Hydrocarbon fluid inclusions occur in a variety of geological environments, most commonly within carbonate rocks from petroliferous sedimentary (Stasiuk & Snowdon,1997). Oil-gas inclusions (OGIs) belong to hydrocarbon inclusions. The sizes of OGIs are usually in the range of 5-20m. A micro-mass (ng-fg) palaeo-oils were trapped in a single OGI. The interaction between OGIs and outside is relative weak although a long geological age elapsing. The OGI can be seen as a closed system. In this way, an intact (not cracked) OGI can be seen as a microoil-gas reservoir. The OGIs take rich information about the palaeo-oils. Generally, in the evolution of the oil-gas reservoir, with the deposition depth increasing, the stratum temperature increases. The organic macromolecules were decomposed into micromolecules. The oil maturity evolutes from low to high. Similarly, in the different digenetic stages, the types, colours and composites of the OGIs are also different. With the maturity of organism from low to high, the types of OGIs are mainly from liquid phase, liquid and gas phase to gas phase. The colours change from colourless, yellow, and brown to black (Liu, Y. R. et al., 2003, as cited in Burruss R.C.,1991). Micro-fluorescence properties of OGIs, largely controlled by the aromatic characteristics of the hydrocarbons, are a signature of the organic chemical composition. This phenomenon was often used to distinguish OGIs from saltwater inclusions. By different fluorescence colours of OGIs, the oil and gas charge history and oil-gas maturity are qualitatively determined. And by the abundance of grains containing OGIs (GOI)(Liu, K. Y. & Eadington, 2005, as cited in Eadington, 1996), the petroleum characteristics of the corresponding strata can be qualitatively estimated. The micro-spectroscopy is very important to OGIs and mainly includes VIS and UV-VIS spectra.