准噶尔盆地车排子地区白垩系沉积特征及演化

Deposition characteristics and evolution of the Cretaceous system of Chepaizi area in Junggar basin

利用钻井、测井、录井和地震等资料,分析岩石结构构造和古生物,研究准噶尔盆地车排子地区白垩系沉积相发育特征.结果表明:研究区白垩系主要发育扇三角洲相和湖相,可以划分为扇三角洲平原﹑扇三角洲前缘和滨浅湖亚相,以及水上分流河道、漫滩沼泽、水下分流河道、水下分流河道间、席状砂、泥滩、滩坝微相.总体为滨浅湖沉积背景,西北部为隆起区,提供物源,向东、南方向逐渐演化为宽缓的斜坡,碎屑物质主要沉积于斜坡的滨浅湖区.从清水河组到连木沁组沉积范围不断往西南部扩大.受湖平面升降、气候变化、沉积物供给等因素的影响,扇三角洲砂体规模较小,滩坝砂体广泛发育,砂体紧靠生油凹陷,是油气聚集的有利场所,易于形成下生上储型油藏,是油气勘探的重要目标.

Using drilling,logging,well logging and seismic data,we analyzed the structure of the rock and paleontology,and researched sedimentary characteristics of Cretaceous in Chepaizi area.The results showed that the Cretaceous in the study area mainly developed fan delta and lake facies,and can be further divided into fan delta plain,fan delta front and shore shallow lake subfacies,and include overwater distributary channel,backswamp,subaqueous distributary channel,subaqueous interdistributary channel,delta front sheet sand,mud flat and beach bar microfaeies.The sedimentary background is shore shallow lake,the northwest is the uplift,and provides the clastic sediments,and gradually evolved into wide slope to the east and south,detritus mainly deposited on the slopes of the shore shallow lake.From the Qingshuihe formation to the Lianmuqin formation,the sedimentary range continuously expanded.Affected by the fluctuation of lake level,climate,sediment supply and other factors,the fan delta sand body is small,beach bar sand body develops extensively,these sand bodies close to the oil source sag,are favorable area for oil and gas accumulation,and easy to form the formation of reservoir,as should be important targets for oil and gas exploration.