东营凹陷牛庄洼陷沙三中亚段滑塌重力流砂体岩相类型及其测井识别

Identification on Sand Bodypetrofacies Type of Dongying Depression Niuzhuang Sag Three Zhongya Section Slump Gravity Flow and Its Logging

为解决东营凹陷牛庄西南地区沙三中亚段重力流砂体的空间分布,综合运用岩心、录井、测井资料及分析测试资料,对研究区重力流砂体的沉积特征和岩相类型进行研究。结果表明研究区主要发育3种沉积砂体,并划分出6种岩相类型:块状层理砂岩相、富碎屑砂岩相、平行层理砂岩相、变形构造粘土砂岩相、韵律层理粘土砂岩相和泥岩相。在此基础上,根据自然伽马(GR)、电阻率(RILD)、声波时差(AC)、地层密度(DEN)、补偿中子(CNL)测井曲线特征,采用Fisher判别法,建立了岩相类型的定量判别函数,并结合测井参数交汇图版,标定了单井岩相类型,对各岩相进行了测井识别,总结出研究区重力流砂体岩相的分布规律:沉积近端以砂质碎屑流沉积为主,中厚层块状层理砂岩相垂向上多与富碎屑砂岩相共生,伴随少量的变形构造粘土砂岩相。沉积远端以薄层低密度浊流沉积为主,发育韵律层理粘土砂岩相。

For solving the space distribution of gravity flow sand body in ThreeZhongya section,Southwest,Niuzhuang,Dongying,we studied sedimentary characteristics and petrofacies type of gravity flow sand body with core,logging,logging information and analyzed information.The result shows that there are 3 sedimentation sand body in the researched area,6 petrofacies types are ensured which are massive bedding sandstone facies,rich clastic sand facies,parallel bedding sandstone facies,deformed structural clay sand facies,rhythmic bedding clay sandstone facies and mudstone facies.Therefore,according to natural gamma（GR）,resistivity（RILD）,acoustic transit time（AC）,formation density（DEN）and compensated neutron（CNL）logging curves characteristics,quantitative discriminant function of petrofacies type was built by Fisher,furthermore,with logging parameter joining plate,identify logging of every petrofacies type and summarize distribution rule of gravity flow petrofacies as follows.Sedimentary near end is dominated by sand clastic flow deposition,the middle thick bedded sandstone facies is usually associated with rich clastic sandstone in the vertical direction,accompanied by a small amount of deformation tectonic clay sand facies.The sedimentary distal area is mainly composed of thin low-density turbidity current deposition,and develops the rhythmic bedding clay sandstone.