构造转换带储集体发育的主控因素——以准噶尔盆地腹部侏罗系为例

Controlling factors of reservoir development in structural transfer zones: A case study of the Inner Junggar basin in Jurassic

本文以准噶尔盆地腹部侏罗系储集砂体分布特征为例,探讨构造变换带优质储层的形成机制与变形特征,开展构造转换带的构造-沉积-成岩作用等对物源、砂体、岩石物理等的控制作用的研究。盆地构造转换带控制主要物源与水系,进而控制沉积体系的发育特征;构造转换带与坡折带共同控制沉积相带展布;构造转换带、坡折及沉积层序格架联合控制砂体时空展布及其储层质量:在大的构造转换带、高坡降比的坡折等条件下,在低位域沉积期发育冲积扇、辫状河和曲流河沉积等,形成大规模的储集体,在高位域沉积期发育较大规模三角洲沉积等。对构造转换带的综合研究,可深化对坳陷盆地沉积体系发育规律认识,进而提高对油气储集体的预测精度,对陆相湖盆沉积学及其油气勘探开发具有重要指导和参考价值。

Taking the sandbody distribution character of the Inner Junggar basin in Jurassic as an example, this paper discusses the formative mechanism and deformation behaviour of high-quality reservoir of structural transfer zones based on the study on the tectonic-sedimentary-diagenesis in structural transfer zones controlling provenances, sand bodys and rock physics and so on. Structural transfer zones control the main provenances and water systems, and then control the development characteristics of the sedimentary systems. Structural transfer zones and slope breaks jointly control the distribution of sedimentary facies. Structural transfer zones, slope breaks and sequence framework control not only the temporal and spatial distribution of sand bodies but also their reservoir qualities： under conditions of large structural transfer zones and slope breaks with high gradient ratio, the lowstand systems tracts mainly develop the alluvial fan, braided river and meandering river depositions, which can form larger-scale reservoirs, while the highstand systems tracts can develop the large-area delta depositions. The study on structural transform zones helps achieve a deeper understanding of the development of sedimentary systems in the depression basin, so as to predict reservoirs more accurately and finally provide guidance to the sedimentology of continental lake basins and their exploration and development.