Research On Sedimentary System Of Chang 2 Of Yangchang Formation In Liandaowan Area Of Shanbei Slope

Ordos basin is a large-scale craton overlapping basin,which locates in western North China platform and possesses abundant hydrocarbon resources.The study of occurrence and distribution features of hydrocarbon should be made by new theories and evolutions of sedimentology,sequence stratigraphy,reservoir sedimentology and petroleum geology form different angles on the base of Neopaleozoic regional geology background.Liandaowan area is in mid Shanbei Slope,which is a considerable producing zone of Ordos basin.Chang2 of Yangchang Formation is an important oil-bearing series,which sedimentary formation was formed in Indosinian orogeny,Late Triassic, sedimentary background is a momentary uplifting in Ordos basin,and exploration and exploitation of hydrocarbon in this area is very important.To further descripte disciplinarian of accumulation hydrocarbon,carefully study on sedimentary facies, reservoir type and disciplinarian of accumulation hydrocarbon of Chang2 of Yangchang Formation in study area is needed.By collecting date of field profile,outcrop,core and many other geological, through sedimentary and oil geological analysis,sedimentary facies types were identified,distributing of sedimentary facies and extension of sand body were analyzed too.Finally,the favorable areas were found out by deeply studying sedimentary system and disciplinarian of accumulation oil&gas in Chang2 of Yangchang Formation,Late Triassic in Liandaowan area.Chang2 of Yangchang Formation is main study formation,which is divided into three members(Chang2₁,Chang2₂ and Chang2₃),Chang2₁ and Chang2₂ are subdivided into three(Chang2₁¹,Chang2₁²and Chang2₁³)and two(Chang2₂¹and Chang2₂²)reservoirs respectively.By defining Layered borderline between every member and detailed describing rock and electro characteristic,member zonation become more reasonable and accurate also sedimentary facies and disciplinarian of accumulation oil&gas in study area are confirmedThrough researching sedimentary facies,reservoir sand and hydrocarbon migration,accumulation,distribution,hydrocarbon accumulation models of Chang2 of Yangchang Formation in study area is pointed out,which is lithologic hydrocarbon reservoir and tectonic-lithologic hydrocarbon reservoir.Different play is formed by different processes and factors,the main controlling factors of hydrocarbon accumulation as flowers:material base of hydrocarbon enrichment is abundant oil sources,main hydrocarbon reservoir is channel sand and reservoir property is influenced by lithogenesis.Through analysis of reservoir property,seal function of cap rocks,trap type and accumulation model,several favorable exploration areas can be found out in Liandaowan area.