松辽盆地北部双城地区扶余油层层序地层格架与沉积体系展布

通过多口岩心精细观察，结合135口探井资料分析，识别出各种沉积微相标志，确定了松辽盆地北部双城地区扶余油层主要为曲流河-浅水三角洲沉积体系，进一步划分为5种亚相、11种微相。以高分辨率层序地层学理论为指导，通过岩-电结合、井-震结合等技术手段，识别层序界面，将其详细划分为2个长期基准面半旋回、7个中期基准面旋回，建立等时层序地层格架。以中期基准面旋回为编图单元，结合地震属性综合分析，编制了不同时期岩相古地理图，分析其演化规律，建立沉积模式，研究表明：研究区扶余油层主要经历了2个大的演化阶段：Q3-sq1-Q4-sq1时期，由浅水三角洲平原沉积逐渐向曲流河沉积转换；Q4-sq2-Q4-sq3时期，由曲流河沉积向浅水三角洲平原、前缘沉积转换，反映水体先变浅又逐渐变深的一次湖退－湖侵沉积过程，为近期油气勘探提供重要的指导意义。

Sequence Stratigraphy Framework and Depositional System Distribution of Fuyu Reservoir in Shuangcheng Area,Northern Songliao Basin

Based on core observation, combined with 135 exploration wells data, various sedimentary microfacies signs were identified. All these showed that Fuyu reservoir mainly developed meandering river-shallow water delta depositional system in Shuangcheng area, Northern Songliao Basin, furtherly divided into 5 subfacies and 11 microfacies. With the guidance of high resolution sequence stratigraphy, using the technologies of rock-electric combination, well-seismic combination and so on, several sequence boundaries were identified. Fuyu reservoir can be divided into 2 long-term base level hemicycles and 7 middle-term base level cycles, and in this way, isochronous sequence stratigraphy framework has been established. Taking middle-term base level cycle as compilation unit, combined with the analysis of seismic attribute, lithofacies paleographic maps in different period were compiled and depositional model was established. Research show that Fuyu reservoir in study area mainly experienced two evolutionary stages: during the period of Q3-sq1-Q4-sq1, shallow delta plain gradually converted to meandering river; while during the period of Q4-sq2-Q4-sq3, meandering river depositional system converted to delta plain subfaceis and delta front subfacies. All these reflected a lake retreat-lake transgression depositional process during which the sedimentary water is firstly shallowing then gradually deepening. The results of above studies provide an important guidance for recent oil and gas exploration.