准噶尔盆地车排子凸起白垩系层序-古地貌耦合控砂机制与砂体预测

Coupling mechanism for sand control and sand body prediction of Cretaceous sequence and paleogeomorphology in the Chepaizi Uplift,Junggar Basin

为明确准噶尔盆地车排子地区白垩系砂体分布规律,根据沉积学、层序地层学等理论,综合利用钻井、测井、录井及三维地震资料,在精细层序地层格架建立的基础上,结合古地貌恢复,分析研究区砂体的时空展布特征。结果表明:白垩系砂体分布受层序—古地貌耦合控制,即层序控制砂体的垂向分布,表现为各三级层序的HST、LST砂体较发育;古地貌控制砂体的平面分布,表现为坡折带沟谷控制扇三角洲砂体的发育,平台区广泛发育滨浅湖滩砂,水下低隆区发育厚层坝砂。该结果为研究区白垩系厚砂体的精准预测提供指导。

In order to clarify the distribution law of Cretaceous sand body in Chepaizi Area,under the guidance of sedimentology,sequence stratigraphy and other theories,the spatial and temporal distribution characteristics of sand body were analyzed based on the establishment of fine sequence stratigraphic framework and the restoration of palaeogeomorphology by comprehensive use of drilling,surveying,logging and three dimensional seismic data.The results show that the distribution of Cretaceous sand body is controlled by sequence-paleogeomorphology coupling,that is,the sequence controls the vertical distribution of sand body,which is manifested in the relatively developed HST and LST sand bodies of each three-level sequence.The paleogeomorphology controls the plane distribution of the sand body,that is,the gully of the slope break zone controls the development of the sand body in the fan delta,the littoral and shallow lake beach sand is widely developed in the platform area,and the thick layer dam sand is developed in the low uplift of the micro-volute underwater.The research results provide guidance for the accurate prediction of Cretaceous thick sand body.