The Study Of Yingcheng Formation Volcanism Influence On Hydrocarbon Source Rock In Songtiao Basin

In recent years， the study of volcanic rock reservoir has made a significantprogress and more and more petroleum geologists put attention to the relationship ofvolcanic rock and source rock.. Volcanic rock can not only be reservoir，but alsoaffect the formation of the source rocks and the process of hydrocarbon evolution.The research are moving on a new stage, such as accumulation of hydrocarbonsource rocks, thermocatalytic of hydrocarbon evolution and hydrogenation catalysis.The topic of this thesis is the organic enrichment of volcanic activity and thesyndeposition source rocks. The contrast between Xujiaweizi depression in thenorth of Songliao Basin and Lishu fault depression in the south is including theabundance of organic, organic matter type and the maturity. Except these, volcanicactivity and volcanic rock of the first member of Yingcheng Formation in Xujiaweizidepression which volcanic activity was very intense is also necessary for theresearch.The experimental data shows that the abundance and maturity of organic ofYingcheng Formation’s source rocks in Xujiaweizi depression is better than that inLishu fault depression，and they had similar organic matter type. These pointsindicate that the source rocks characteristics of Xujiaweizi depression is better thanLishu fault depression.The volcanic rocks of the first member of Yingcheng Formation in Xujiaweizidepression have a wide distribution, a big thickness and complex lithology, multi-gyrations and phases. All of these display that the volcanic activity wasintensely in Yingcheng Formation， in Xujiaweizi depression. To the contrary, thevolcanic rocks in Lishu fault depression are nondevelopment，who have a smallrange, a thin stratum and single lithology. Above of these show that volcanic activitywas weakly in Yingcheng Formation, in Lishu fault depression. We know thatabundant nitrogen and phosphorus and mineral composition were enter into the lakebasin，and massive gas-liquid material were also enter into the lake basin such asH₂S、SO₂、CO₂、CH₄and so on, by using the research on the influence of underwatereruption on the source rocks and underwater volcanic activity characteristics. Theywere react with H₂O and O₂in the water，and increased salinity that cause lakestratification and formed a reducing environment. This is useful for preservation andtransformation of the source rocks. Therefore，it could be infered that volcanicactivity of the first member of Yingcheng Formation in Xujiaweizi depressionpromote organic enrichment of source rocks in Yingcheng Formation.