摘要
基于地球化学、地震、测井和钻井等资料,对松辽盆地北部下白垩统泉头组扶余油层地质特征、致密油富集主控因素及富集模式等进行系统分析.研究表明:①泉头组上覆上白垩统青山口组优质烃源岩,环凹鼻状构造发育,沉积砂体大面积连续分布,储层整体致密;②优质烃源岩、储层、断裂、超压和构造等多要素配置联合控制扶余油层致密油富集.源储匹配关系控制致密油分布格局;源储压差为致密油富集提供充注动力;断砂输导体系决定油气运移和富集;正向构造是致密油富集的有利场所,断垒带是向斜区致密油勘探重点突破区带;③基于源储关系、输导方式、富集动力等要素建立扶余油层致密油3种富集模式,一是源储对接油气垂向或侧向直排式:"源储紧邻、超压驱动、油气垂向倒灌或源储侧向对接运聚";二是源储分离断裂输导式:"源储分离、超压驱动、断裂输导,油气通过断层向下运移到砂体富集";三是源储分离断砂匹配式:"源储分离、超压驱动、断裂输导、砂体调整、油气下排后通过砂体侧向运移富集";④油源条件、充注动力、断裂分布、砂体以及储层物性等方面的差异性造成扶余油层致密油的差异富集,齐家—古龙凹陷扶余油层具有较好富集条件,勘探程度低,是未来致密油探索重要新区带.
Abstract
Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral transport of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is transported vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.
维普
万方数据