The Research Of Volcanic Activity And The Tectonic Stress To The Inorganic Gas Origin In Changling Region, Southern Songliao Basin

Changling fault depression is located in the central depression of the South of Songliao Basin. The exploration is insufficient, but the potential of petroleum resources is immense. the deep well of YS1 was discovered in-depth research area's, which proves that there is much room for improvement in the abiogenetic gas reservoir and it will be strategic resource. According to the research of predecessors on organic genetic gas reservoir, the author analyzes the control action of volcanicity and tectonic stress to the abiogenetic gas reservoir.Based on the outcrops observation and the research of predecessors on crack-statistics, the author analyzes stress field, and further distinguishes different periods of tectonic stress field distribution and deformation behavior. The research shows that under the different stages and directions of stress fields, the structures and faults in the different directions can generate different activities (such as compression, extension and strike-slip, etc.), which has different effect on the formation of abiogenetic gas. Thus, the tectonic stress field may influence the formation of abiogenetic gas, and it can be an important factor in inferring origin of abiogenetic gas reservoir. Through the study of the regional tectonic stress field, the author has solved the control action of tectonic stress field to the distribution of discordogenic fault which is not only used to construct channel of the migration of abiogenetic gas, but also indicates the direction of migration.The exploration results show that the CO2 in the study area mainly spreads over Yingcheng Formation, which is consistent with the distribution characteristics of volcanic, while in the different positions of the same tectonic zone, the different contents of CO2 also indicate that it is not only related to the volcanicity, but also associated with the volcanicity stages. According to the research of predecessors on volcanicity and cycle, the author analyzes the relationship between magmatism in different periods and abiogenetic gas reservoir. The study shows that Songnan abiogenetic gas reservoir is most distributed at well developed area of volcanic rocks, and affected by different volcanicity stages, and the scale of accumulation of reservoir formation is different, which serves as an further guideline for the exploration and development of abiogenetic gas.