松辽盆地大安油田葡萄花油层沉积微相特征及其演化

Characteristics and Evolution on Sedimentary Microfacies of Putaohua Reservoir in Daan Oilfield,Songliao Basin,China

基于高分辨率层序地层学及储层沉积学理论,利用岩心、测井曲线、分析化验等资料,研究松辽盆地大安油田葡萄花油层沉积特征及演化。通过对泥岩颜色、生物化石、沉积构造、储层岩石学特征、特殊矿物及沉积背景等分析,确定研究区葡萄花油层发育浅水三角洲前缘沉积、前浅水三角洲沉积和浅湖—半深湖沉积。其中,浅水三角洲前缘亚相可进一步细分为水下分支河道、水下天然堤、水下分支河道间湾、河口坝和远砂坝5种微相。并对研究区沉积相进行了单井岩心相分析、测井相分析、连井相对比和平面沉积微相研究。大安油田葡萄花油层沉积时期,三角洲为先进积后退积:葡萄花8—4小层(P8—P4)时期,为湖盆萎缩、三角洲进积的阶段;葡萄花4—0小层(P4—P0)时期,则为湖盆扩张、三角洲退积的过程。物源来自北西方向的白城水系。

On the foundation of high-resolution sequence stratigraphy and Reservoir sedimentology theory,coring,logging,laboratory analysis and other data were used to research on characteristics and evolution of sedimentary microfacies of Putaohua reservoir in Daan oilfield.According to analysis on mudstone colour,fossil organism,sedimentary structures,petrologic characteristics,special minerals and sedimentary background,shallow-water delta front,prodelta and shallow-semideep lacustrine facies were recognized in the study area.Shallow-water delta front can be divided into 5 kinds of microfacies,including underwater distributary channel,underwater natural levee,underwater interdistributary area,channel bar and distal bar.Single well facies analysis,electrofacies analysis,well-to-well facies analysis and plane distribution of sedimentary microfacies were conducted.Shallow-water delta were prograde in the early time,and retrograde in the following time in Daan Oilfield,during Putaohua Reservoir was deposited,with provenace from Baicheng drainage in northwest.During P8-P4 were developed,shallow-water delta was developed gradually from northwest to southeast and shallow-semideep lacustrine facies were shrunk bit by bit.While P4-P0 were deposited,shallow-water delta was shrunk from southeast to northwest and shallow-semideep lacustrine facies became more and more developed.