Evaluation Of The Hydrocarbon-generating Potential And Features Of The Middle-upper Proterozoic Source Rocks In North Huabei Area

According to the lithological association,contact relationship and tectonic movements for the Mid-Upper Proterozoic stratum of North Huabei Area,5 supersequences and 19 Level 3 sequences are classified.Each three level sequence developments transgression system tract and highstand systems tract,Part of them development lowstand system tract.On the basis of this,We summarize the reservoir types and reservoir space types,effective reservoir evaluation system has been established.The results reveal that carbonate reservoirs of Mid-Upper Proterozoic are controlled by sedimentation,diagenesis,tectonic and karstification and mainly distributed in upper tieling formation,wumishan group of four,gaoyuzhuang group of three and one and upper tuanshanzi formation.The ancient karst reservoirs mainly distributed in upper tieling formation and upper tuanshanzi formation and traverse quite be stable.Based on the analysis of abundance of organic mattesr,organic matter type and maturity of organic matter,the result indicate that:(1)the shale of hongshuizhuang formation has the highest abundance of organic matter,followed by xiamaling formation.In carbonate rocks,tieling formation has the highest abundance of organic matter and is a set of effective oil source rock.(2)the kerogen type of Mid-Upper Proterozoic is mainly I type,few II1 type.(3)the maturity of organic matter indicates:formations above wumishan formation are at oil genetation stage and xiamaling formation is at gas genetation stage.And on this basis we calculate hydrocarbon generation quantity of 5 sets of source rocks,the results indicate hongshuizhuang formation and xiamaling formation have the highest generation quantity.Based on the dissection of representative wells,the paleo-reservoir in tieling formation of shuangdong anticlinal mainly come from tuffs of tieling formation,xiamaling formation provided parts of source,which give us a revelation that large-scale hydrocarbon migration and accumulation happened in tieling formation.The analysis of fluid inclusions from tieling formation shows that after large-scale tectonic movement,the processes of generation,migration and accumulation are still exists in shuangdong area.Combining the results of evaluation source rocks and HC-generating position of the center and the distribution of favorable reservoir-cap rocks,weo ptimize 3 favorable areas: dangba depression,jingxi area and north of Jizhong area.dangba depression belongs to type I area and jingxi area and north of Jizhong area belong to type II area.In these 3 favorable areas grow some key tectonic belts:puhe tectonic belt,kunminghu anticlinal and fengheying anticlinal belt.