Therefore, geologists have gradually applied it to the study of petroleum exploration and the hydrocarbon accumulation period, which has become an important link in oil and gas exploration and has important practical significance to solving the theoretical and practical problems. As one of the most direct and effective methods to study fluid properties in a paleodiagenetic environment, fluid inclusions contain abundant information about paleo-temperature, pressure and paleo-fluid composition. In the process of mineral crystallization and growth, the part of a material that is wrapped in mineral lattice defects or holes, and is still sealed up in the main mineral, and has a phase boundary with the main mineral is called fluid inclusion. Combined with the measured organic matter Ro > 2.0% in the study area, the corresponding time of the pyrolysis charging period was determined to be 100 - 120 Ma when projected into the thermal evolution history. In addition, according to the characteristic peaks of a large number of asphaltene inclusions (or asphaltene-containing methane inclusions) in Raman test results, it is speculated that there is a second accumulation stage, namely the cracking stage of wet gas and condensate oil. Combined with the homogenization temperature of inclusions and the recovery results of thermal evolution history, the first stage was the kerogen cracking gas stage, and the homogenization temperature range of associated brine inclusions was 100☌ - 170☌, and the main charging time was estimated to be 120 - 205 Ma. The inclusions are mainly distributed in the healed microcracks, quartz edge enlarging and cracks, and the hydrocarbon inclusions are mainly distributed in the healed microcracks. The results show that there are five types related to hydrocarbon accumulation in the study area, and the hydrocarbon inclusions mainly include the following four types: 1) methane inclusions 2) asphalt-containing methane inclusions 3) asphaltene inclusion 4) methane inclusions containing CO2. Finally, the accumulation period was determined based on burial history. In order to clarify the gas accumulation process of Upper Paleozoic in Daning-Jixian area, the fluid inclusions in the study area were tested and analyzed comprehensively by single polarizing microscope observation, laser Raman spectroscopy analysis and microthermometry.
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