冲积扇砾岩储层构型特征及其对储层开发的控制作用——以准噶尔盆地西北缘某区克下组冲积扇储层为例

冲积扇砾岩储层作为陆相沉积储层十分重要的类型之一,一直是我国油气勘探开发的重点领域。以准噶尔盆地西北缘某区下克拉玛依组为例,根据砾岩储层相变快、储层非均质性强等特点,在沉积相分析的基础上,对储层构型特征进行了精细分析,将储层划分为槽流砾石体、槽滩砂砾体、漫洪内砂体、漫洪内细粒、片流砾石体、漫洪外砂体、漫洪外细粒、辫流水道、辫流砂砾坝、漫流砂体、漫流细粒、径流水道和水道间细粒共13种构型单元,其中以槽流砾石体、片流砾石体、辫流水道和辫流砂砾坝占主导。构型解剖结果显示:研究区砾岩储层槽流砾石体平面呈条带状,剖面厚度大,为2~8m;片流砾石体沉积厚度大,一般为2~7m;辫流水道构型单元宽度为80~400m,剖面呈透镜状,厚度为2~7m;辫流砂砾坝沉积厚度较大,为2~7m。上述构型单元受北部和西北部方向物源控制明显。储层构型特征能有效反映储层非均质性、连通性等属性,对油田开发具有较强的控制作用。

Characteristics of Conglomerate Reservoir Architecture of Alluvial Fan and Its Controlling Effects to Reservoir Development:Taking Alluvial Fan Reservoir in Some Area of Northwest Margin of Junggar Basin as an Example

Being one of the important kind of reservoir,conglomerate reservoir always was hotpot area to explorationists and developers of oilfield.Taking Lower Karamay Formation of some area in northwest margin of Junggar basin as an example,it characteristics of sedimentary facies quick changes and heterogeneity intensity.reservoir architecture characteristics were finely analyzed on the base of sedimentary facies studied.The reservoirs were carved into thirteen kind of architecture,such as, channel flow conglomerate,channel beach conglomerate,sandstone of inner belt of sheet flood,fine grained of inner belt of sheet flood,laminar flow conglomerate,sandstone of exterior belt of sheet flood, fine grained of exterior belt of sheet flood,braided channel,braided sandstone-conglomerate dam, sandstone of unconcentrated flow,fine grained of unconcentrated flow,streamflow channel,fine grained between streamflow channels.And channel flow conglomerate and laminar flow conglomerate and braided channel and braided sandstone-conglomerate dam take the leading roles.The results of reservoir architecture analyzed indicated development laws of different kind of architecture. Channel flow conglomerates extend like banding,and had thickness from two meters to eight meters.Laminar flow conglomerates are two meters to seven meters in vertical section.Braided channels are wide about eighty meters to four hundred meters.Braided sandstone-conglomerate dams take thickness about two meters to seven meters.All kinds of architecture are controlled by the sedimentary source of north and north-west directions.Reservoir architecture characteristics could finely reflect the properties of reservoir of heterogeneity and connectivity.And it has an important controlled function to oilfield development.