春光探区西南部白垩系胜金口组扇三角洲沉积特征

Sedimentary characteristics of fan delta of Cretaceous Shengjinkou formation in southwestern Chunguang exploration area

为解决春光探区西南部白垩系沉积特征研究精度与目前勘探开发需求不匹配的问题,利用岩心岩屑及分析化验、钻井、测井、地震等资料,结合三色混相分频技术,对春光探区西南部白垩系沉积特征开展了较高精度的系统性研究。结果表明,西南部白垩系发育扇三角洲沉积,包括扇三角洲平原和扇三角洲前缘两种沉积亚相,识别出扇三角洲平原辫状分流河道、漫滩沼泽,以及扇三角洲前缘水下分流河道、水下分流河道间、河口砂坝等五种沉积微相;并结合岩心资料和地层精细对比明确了西南部白垩系胜金口组扇三角洲砂砾岩成藏期次(分为三期),利用三色混相分频技术准确刻画了每一期次沉积朵叶体的形态和平面展布,为后期勘探开发部署提供了依据。

In order to solve the problem that the research accuracy of Cretaceous sedimentary characteristics in southwestern Chunguang exploration area is not applicable to the current exploration and development needs,a high-precision systematic research on Cretaceous sedimentary characteristics in southwestern Chunguang exploration area is carried out by using core,thin section,analysis and test,drilling,logging,seismic and other data,combined with RGB mixed phase frequency division technology.The results show that fan delta deposits are developed in the Cretaceous in the southwest,including two sub-facies of fan delta plain and fan delta front.Five sedimentary microfacies such as braided distributary channel of fan delta plain and underwater distributary channel of fan delta front are identified.Through core data and stratigraphic fine correlation,it is clear that the reservoir forming period of fan delta sandy conglomerate of Shengjinkou formation in the Cretaceous in the southwest is divided into three phases.The shape and plane distribution of multiple lobes deposited in each stage are accurately characterized by RGB mixed phase frequency division technology,which provides a basis for later exploration and development deployment.