松辽盆地北部西部斜坡高台子油层三砂组沉积微相研究

大量岩心、录井及测井资料分析结果表明，松辽盆地北部西部高台子油层三砂组发育的沉积相类型有湖泊相和三角洲相。湖泊相中发育滨浅湖亚相，滨浅湖亚相又可区分为砂质滩坝、混合滩和泥滩3种沉积微相。三角洲相主要发育三角洲前缘亚相的河口坝和远砂坝微相。高台子油层三砂组时期，受齐齐哈尔物源、北部物源、西部物源和西南物源供应的影响，形成了5个三角洲朵体。其中齐齐哈尔物源、北部物源和西南物源形成的三角洲规模较大，而西部物源形成的三角洲规模较小。三角洲以前缘亚相为主，主要发育河口坝和远砂坝沉积微相。在富62井—富13井一带、杜408—杜45井一带和杜431—塔4井一带，发育滨浅湖砂质滩坝沉积微相。其中沿最大湖岸线带状分布的富62井一富13井一带的滨浅湖砂质滩坝规模较大。其余地带，以富泥的滨浅湖混合滩微相为主。在江36井和来54井附近分别发育了滨浅湖泥滩微相。砂地比对沉积微相具有较为敏感的反映。在河口坝和砂质滩坝沉积微相发育区，砂地比普遍在0．4以上，在远砂坝发育区，砂地比在0．3左右，在滨浅湖混合滩发育区，砂地比在0．2左右，在滨浅湖泥滩发育区，砂地比普遍小于0．1。

Study on Sedimentary Microfacies of No. 3 Sand Group of Gaotaizi Reservoir in West Slope in Northern Songliao Basin

The analysis result of abundant cores,logging,and well logging data reveals lacustrine facies and delta facies are main sedimentary facies types of No.3 sand group of Gaotaizi reservoir in north and west slope of Songliao Basin.Lacustrine facies are composed of shore-shallow lacustrine subfacies,which are subdivided into 3 sedimentary mircorfacies: sandy beach-bars,mixed beaches and muddy beaches.Delta facies are mainly composed of delta frontal edge esuarine bars and distal end bars.During its sediment,No.3 sand bed formation of Gaotaizi reservoir forms five delta lobe bodies,under the influence of Qiqihaer,north,west and southwest material sources.The deltas formed by Qiqihaer,north and southwest material sources are larger than that formed by west material source.The deltas developed into frontal edge subfacies,which are composed of estuarine bars and distal end bars microfacies.No.3 sand bed formation of Gaotaizi reservoir developes shore-shallow lacustrine sandy beach bars microfacies in the area of Fu 62 well-Fu13 well,Du 408 well-Du 405 well and Du 431 well-Ta 4 well.The distribution of zonary shore-shallow lacustine sandy beach-bars along the maximum lacustine bank line in the area of Fu 62 well-Fu 13 well is bigger.In other areas,shore-shallow lacustrine mixing beaches microfacies mainly developed with rich muddy sediments.Near Jiang 36 well and Lai 54 well shore-shallow lacustrine muddy beaches microfacies developed.Sandstone-mudstone rate is sensitive to sedimentary microfacies.In the area where estuarine bars and sandy beack-bars micorfacies developed,sandstone-mudstone rate is generally above 0.4.!In the area where distal end bars micorfacies developed,sandstone-mudstone rate is nearly 0.3.In the area where shore-shallow lacustrine mixing beaches micorfacies developed,sandstone-mudstone rate is nearly 0.2.In the area where shore-shallow lacustrine muddy beaches micorfacies developed,sandstone-mudstone rate is generally under 0.1.