【作者】 刘宗堡；

【导师】 吕延防；

【作者基本信息】 东北石油大学 ， 矿产普查与勘探， 2010， 博士

【摘要】 三肇凹陷扶余油层作为松辽盆地北部增储上产的一个重要勘探领域,自上世纪60年代钻井获得工业油流以来,先后开展了综合石油地质研究、精细油藏描述和储层砂体地震预测技术,但由于断层特征复杂和河道砂体预测较难,油气勘探一直未获重大突破。本文以高分辨率层序地层学、储层沉积学和成藏动力学理论为指导,以三肇凹陷扶余油层为研究对象,系统开展了高分辨率层序地层划分与对比、成因单砂体级沉积微相、断层特征、古构造演化、油水分布和油气运移路径模拟等成藏主控因素及时空匹配关系研究。高分辨率层序地层学研究表明三肇凹陷扶余油层可以识别出1个基准面下降到上升的转换面(冲刷面)和5个基准面上升到下降的转换面(湖泛面)；根据各级层序界面沉积学响应特征,以湖泛面为层序界面将扶余油层划分为1个长期旋回、4个中期旋回、17个短期旋回和35个超短期半旋回,最终建立了研究区单砂体级等时地层格架；并提出了扶余油层为先缓慢水退后快速水进的层序格架,水退最大期位于扶Ⅰ组底部；油气分布受控于中、长期旋回变化,主要位于长期旋回上升早期的中期旋回下降晚期或上升早期储层砂体中。超短期旋回内沉积特征研究表明扶余油层发育典型的河控浅水三角洲沉积,微相类型以分流河道砂体为主,其它类型微相不发育,沉积微相垂向演化表明扶余油层顶部(FⅠ1-FⅠ3小层)发育三角洲前缘亚相,中下部(FⅠ4-FⅢ4小层)发育三角洲分流平原亚相,底部(FⅢ5小层)发育三角洲前缘亚相；重矿物、地层厚度和开发区砂体精细解剖表明研究区主要受北部拜泉-青冈物源和西南保康物源影响,并不发育东南长春-怀德物源。断层特征研究表明T2断层受控于基底断层、下部火山口、斜向拉张和伸展量差异等因素具有平面密集成带、剖面“似花状”组合特征,提出由于厚层泥岩塑性变形大部分T2断层向上并未断穿青山口组地层,因此油气成藏期继承性活动且沟通上覆烃源岩和下伏扶余油层储层的油源断层主要为断层密集带边界断层。扶余油层受断层密集带和古构造演化控制表现为“堑-垒”组合模式,断层密集带内为地堑,断层密集带两侧为地垒或断阶,凹陷向斜区油主要分布在断层密集带之间,凹陷斜坡区断层密集带受后期构造反转作用多表现为“隆中堑”特征,整体处于构造高部位,且为油气优势输导通道,因此凹陷斜坡区油主要分布在断层密集带内及两侧附近。上述研究表明古构造演化、砂体展布和断层特征匹配关系是控制扶余油层油运聚成藏的关键,最终建立了三肇凹陷不同构造部位3种油成藏模式,并刻画出52个富集目标区,为松辽盆地北部扶余油层下一步的勘探与开发提供了指导。更多还原

【Abstract】 As an important exploration field of increasing reserves and yield in northern Songliao Basin, Fuyu reservoir of Sanzhao depression has in turn launched comprehensive petroleum geology study, fine reservoir description and reservoir sandbody seismic forecasting techniques since 1960s, when industrial oilflow was drilled out, but for complicated fault property and hard forecasting of river sandbody, important breakthrough in hydrocarbon exploration has not been reached. In this paper, we followed the guidance of high-resolution sequence stratigraphy, reservoir sedimentology and reservoir dynamics theory, took Fuyu reservoir of Sanzhao depression as the subject of study, systematically launched the study of key controlling factors of reservoir forming and space-time matching relationship, as high-resolution sequence stratigraphy division and correlation, microfacies of single sand body level, fault characteristics, paleo-tectonic evolution, oil and water distribution and petroleum migration path imitation etc.High-resolution sequence stratigraphy study shows that it can identify a base level decrease-to-increase conversion surface (erodsion surface) and five base level increase-to-decrease conversion surface (flooding surface) of Fuyu reservoir in sanzhao depression; and according to sedimentary responses of sequence boundaries at all levels, to flooding as the sequence boundary surface, Fuyu reservoir can be divided into a long-term cycle,4 medium-term cycles,17 short-term cycles and 35 ultra short-term half-cycles. We established a isochronicly stratigraphic framework of single sand body level for study area, and proposed that stratigraphic framework of Fuyu reservoir is from slow water withdrawal to fast water advance, and maximum withdrawal of water is at the bottom of FI group, hydrocarbon distribution is controlled by the long and medium term cycle, and is mainly located in the reservoir sand of late fall or early rise period of medium-term cycles in early rise period of long-term cycles. Sedimentary features study of ultra-short-cycle shows that typically river-controlled shallow delta deposition was developed in Fuyu reservoir, distributary channel sandbody was the main microfacies and other microfacies was not well developed. Vertical evolution of microfacies shows at the top of Fuyu reservoir (FI1-FI3 layer) developed delta front, at the lower part (FI4-FIII4 layer) developed delta plain, and at the bottom developed (FIII5 layer) delta front microfacies. Study of heavy minerals, formation thickness and fine anatomy of dense well pattern sand of development area indicates the study area is mainly affected by northern and southwestern Baokang source, and southeastern Changchun-Huaide source is not developed. Fault characteristic studies suggest that fault T2 is controlled by basement fault, the lower crater, diagonal tension and differences in extension and so on, and concentrated into band in plane, while combined as "flower-like" in profile. Inherited move boundary fault in fault-intensive zone is the main source fault that links overlying source rocks and underlying reservoir of Fuyu reservoir during hydrocarbon accumulation.Fuyu reservoir is " graben-horst" combination model controlled by fault-intensive zone and the paleo-tectonic evolution. Within the fault-intensive zone is graben, while both sides fault-intensive zone is horst or fault terrace, so oil of syncline is mainly distributed between fault-intensive zones. Fault-intensive zone of slope area is usually "horst in upheaval" under the control of later tectonic reversal, wholly located at high structural position and is preponderant transporting passage, so oil of slope area is mainly distributed within or near fault-intensive zone.The study shows that the paleo-tectonic evolution, sandbody distribution and the fault characteristics reason matching is the key for dominate oil transportation and accumulation in Fuyu reservoir. Eventually, we set up three oil and gas accumulation model in different parts of Sanzhao Depression, and depict 52 enrichment target area, which will provide guidance for further exploration and development of Fuyu reservoir in northern Songliao basin.更多还原