关键词: 致密气, 近源-远源, 爆发相, 溢流相, 火山岩, 营一段, 白垩系, 莺山-双城断陷, 松辽盆地

Abstract: Based on the analysis of structural characteristics，reservoir accumulation stages and conditions，the distribution characteristics and main controlling factors of Cretaceous tight volcanic reservoirs in Yingshan-Shuangcheng fault depression of Soliao Basin were determined by using the data of seismic，inclusions，source rocks and production test. The results show that：（1）Yingshan-Shuangcheng fault depression has experienced threestage extension and compression tectonic activities. During the late sedimentary period of Qingshankou Formation（84-88 Ma）which was the main reservoir accumulation stage，the study area was in a stable depression period with weak tectonic activities，which was conducive to the formation and preservation of gas reservoirs.（2）The volcanic reservoirs in the study area are dominated by pyroclastic rocks and lava，with porosity and permeability of 9.6% and 0.93 mD. The source rocks of Shahezi Formation have high organic abundance，TOC（total organic carbon content）and S₁+ S₂（hydrocarbon generation potential）are 2.61% and 0.62 mg/g respectively，and the average vitrinite reflectance R_o is 3.26%，which is in an over-mature stage. The gas migrated into volcanic rocks of the first member of Yingcheng Formation through faults and unconformities.（3）The natural gas accumulation in Yingshan-Shuangcheng fault depression is controlled by hydrocarbon source rocks，faults，unconformities，volcanic bodies and their coupling relations. The differential activities of faults control the development and superposition of the first member of Yingcheng Formation and Shahezi Formation. The source rocks of Shahezi Formation are developed locally in the northern Yingshan fault depression，while the source rocks of the first member of Yingcheng Formation are mainly developed Sizhan-Taipingzhuang fault. The gas reservoirs are concentrated near the high-over mature source rocks with R_o greater than 3.0%，and the high yield gas wells are distributed circularly around the hydrocarbon generation center. The reservoirs of explosive facies and overflow facies near faults and unconformities that connected source have good physical properties and are important gas enrichment areas.（4）There are two accumulation models of natural gas reservoirs in the study area： “lower generation and upper reservoir， fault matching，near source and vertical migration” in Yingshan fault depression and “lateral generation and lateral reservoir，fault associated with unconformity，far source lateral migration and accumulation” in Shuangcheng fault depression. The structural-lithologic gas reservoirs in Yingshan fault depression are the most favorable exploration area in the study area.

Key words: tight gas, near-source and far-source, explosive facies, overflow facies, volcanic rocks, the first member of Yingcheng Formation, Cretaceous, Yingshan-Shuangcheng fault depression, Songliao Basin