【摘要】 松辽盆地下白垩统青山口组是盆地内中生界最重要的含油层段之一,青山口组三段Ⅻ砂组储集砂体发育,成因类型多样.为分析大情字井油田Ⅻ砂组沉积微相类型,在岩心观察的基础上,综合分析区域地质、地震、测井、录井、粒度、岩性等资料,认为研究区发育水退背景下的三角洲沉积体系.Ⅻ砂组沉积时期,湖盆快速衰退,物源水系不稳定,主要来自于西南和南部的通榆─保康水系,三角洲朵体发生大规模迁移,继承青二段时期三角洲沉积的特点,三角洲平原和前缘亚相发育较广,前三角洲较少发育,识别的主要微相类型有分流河道、水下分流河道、河口砂坝、前缘砂坝和滨外砂坝等.储层物性受沉积微相的影响,研究区分流河道、河口砂坝储集砂体物性显示最好.更多还原

【Abstract】 The Qingshankou formation of lower Cretaceous in Songliao Basin is one of the most important Mesozoic basin oil layers,the Ⅻ sand group of the Qingshankou formation developed lots of sand bodies of various types.In order to figure out the sedimentary microfacies of the Ⅻ sand group of the 3rd member of Qingshankou formation,based on the description and observation of the core,combined with the regional geology,seismic,logging,grain size,and lithological characters,the investigation into the sedimentary microfacies of the Ⅻ sand group of the 3rd member of Qingshankou formation have been carried out in detail.The results show that the target area develops the delta sedimentary system under the background of the water back.During the sedimentary period of Ⅻ sand group,the lake basin recession accelerated,the sedimentary sources of water system was not stable,and mainly came from the Southwest and South of Tongyu-Baokang drainage.The delta body migrated massively,finally inherited the characteristic of the delta sedimentary system of the 2nd member of Qingshankou formation.The studied area mainly developed the delta plain and frontdelta,but the prodelta developed slightly.We mainly identified the distributary channel,underwater distributary channel,channel mouth bar,front bar,and offshore bar.It is obvious that the reservoir property is significantly affected by sedimentation,the reservoir property of the distributary channel and channel mouth bar in the research area are the best.更多还原