【摘要】 为了探讨层序格架对油气成藏的控制作用,深入了解层序和沉积之间的关系,综合运用地震、岩心、测井等资料及井-震结合对比分析,将塔中地区志留系划分为两个三级层序,结合油气成藏条件分析,提出了层序格架控制下的油气成藏模式.结果表明:塔中地区志留系存在4类油气成藏模式.海侵构造型,受层序与构造双重控制,SQ1海侵域下沥青砂岩段发育砂坪和潮汐水道优质储层,与上覆灰色泥岩形成优质储盖组合,油气经断裂向上运移,在构造高部位可成藏;高位岩性型,受沉积与断裂控制,SQ1高位域上沥青砂岩段和SQ2高位域上砂岩段多为混合坪沉积,易形成岩性圈闭,油气由断裂及连通砂体运移至其中可成藏;地层型,受控于层序地层展布,SQ1底部下沥青砂岩存在地层超覆,受上覆泥岩遮挡可形成地层不整合遮挡型或岩性上倾尖灭型油气藏;在井区北部地层埋藏较深未遭受剥蚀区域发育有古油藏残余型.更多还原

【Abstract】 In order to explore the control action of sequence stratigraphy framework on hydrocarbon accumulation as well as the relationship between sequence and sedimentation,the Silurian in Tazhong area was divided into two three-level sequences in comprehensive use of the seismic,core,logging,and combination seismic with wells.In addition,this study proposed the model of hydrocarbon accumulation under the control of sequence stratigraphic framework.The results show that: there are 4 types of hydrocarbon accumulation models in Silurian of Tazhong area.Transgression structure type is controlled by both sequence and structure.High quality sand flat and tideway reservoirs developed in lower bituminous sandstone in transgressive systems tract of SQ1.Combined with overlying grey mudstone cap,a high quality reservoir-seal assemblage could be formed.Oil and gas migrate by faults,and could accumulate in structure high position.Highstand lithology type is controlled by sedimentation and faults.Mixed flat is deposited both in upper bituminous sandstone in highstand systems tract of SQ1 and upper sandstone in highstand systems tract of SQ2,where the lithological trap is easy to form.Oil and gas are accumulated by being migrated by faults and connected sand body.Stratigraphy type is controlled by strata distribution.Stratigraphic overlap developed in the bottom of lower bituminous sandstone of SQ1,where stratigraphic unconformity barrier type or lithology up dip pinchout type reservoirs could be developed by the overlying mudstone barrier.Residual ancient reservoirs exist in north area where the strata are deeply buried and not be denuded.更多还原