春光油田排2-400井区沉积微相研究

Sedimentary Microfacies of Wellblock Pai 2-400 in Chunguang Oilfield

针对春光油田排2-400井区特殊的古地貌特征,利用构造精细解释与三维可视化技术,刻画了研究区内古冲沟的分布范围及形态特征。对研究区目的层的岩性、粒度及沉积构造等特征展开研究,确定了该区沉积体系类型,并对沉积微相进行了详细划分,最后提出了该区的沉积模式。研究认为:春光油田排2-400井区发育南低北高、南宽北窄、西深东浅的不规则U型沟谷,沉积类型为干旱-半干旱气候条件下的冲积扇,其主体区域位于冲积扇的扇中与扇端交汇处,沉积微相可细分为辫状水道、泥石流、漫流砂体、水道间及泥质沉积,其沉积模式为受古冲沟限制的冲积扇沉积。

In consideration of special characteristics of the palaeogeo morphology in Wellblock 2-400 of Chunguang Oilfield,the technologies of fine structural interpretation and 3Dvisualization were used to depict the feature of distribution and shape of the palaeogully.Based on the investigation of lithology,granularity and sedimentary structure in the study area,the type of sedimentary system was determined,sedimentary microfacies was subdivided,and finally the sedimentary mode was proposed in the area.Study results show that irregular U-shaped gullies are developed in the wellblock,it has the characteristics of low side in the south,high side in the north,it is wide in the south and narrow in the north,deep in the west and shallow in the east.The sedimentary type is alluvial fan formed in the climate situation of arid to semi-arid,the intersection area between middle and end sections is the main area of the wellblock.The sedimentary microfacies can be subdivided into braided channel,debris flow,sheet flood sand,interchannel and argillaceous sediment,and the sedimentary mode is alluvial fan deposit limited by palaeogully.