四川盆地寒武系洗象池群层序地层划分及层序地层格架的建立  

Sequence Stratigraphic Subdivision and Establishment of Sequence Stratigraphic Framework in the Cambrian Xixiangchi Group of Sichuan Basin

作　　者：贾鹏[1] 李明[1] 卢远征[1] 樊茹[1] 李鑫[1] 邓胜徽[1] 曾乙洋 刘鑫 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油西南油气田公司,成都610000

出　　处：《地质科技情报》2017年第2期119-127,共9页Geological Science and Technology Information

基　　金：国家重大专项(2011ZX05004-002)

摘　　要：四川盆地寒武系洗象池群发育大套白云岩,由于岩性、电性差异小,化石稀少,地层厚度变化大,层序划分与演化特征一直存在很大争议。基于层序地层学及沉积学相关理论研究,通过对露头剖面、钻井岩心的观察及测井资料的研究,结合测井曲线频谱趋势分析技术及碳氧同位素相关数据,开展对洗象池群层序地层的划分及建立全盆地统一的层序地层格架研究。盆地内虽然基本都是一套白云岩,各分区命名差异大,但依然具有全盆范围内可对比的不整合界面和最大海泛面。研究认为四川盆地洗象池群可划分为4个三级层序,并且厘定了盆地内各分区间的层序地层对应关系。在建立全盆地层序地层格架的基础上,发现洗象池群地层分布呈西薄东厚的楔形体,其中遂宁-乐至-资阳以西缺乏洗象池群沉积。层序格架内有利储集层的分布明显受控于层序界面,其中颗粒滩相主要发育在高位体系域。Carbonate rocks are the dominant rock type in the Cambrian Xixiangchi Group of Sichuan Basin. Due to the little electric and lithology difference, fossil rarity and change of formation thickness, the se- quence division and evolution characteristics are very controversial. Based on the sequence stratigraphy and sedimentology theory, in combination with the data of outcrops, drilling cores and well logging, this paper studied the sequence stratigraphic subdivision and establishment of sequence stratigraphic framework by u- sing the spectralcurvetrend attribute analysis, together with the data of carbon oxygen isotope in the Cam- brian Xixiangchi Group of Sichuan Basin. Despite of the dominant rock type in the Basin and different na- ming system in each partition, the traceable unconformity and maximum marine flooding surface enable the study to continue. The Xixiangchi Group of the basin is divided into four third-order sequences, with the sequence stratigraphy correspondence between each partition established. Based on establishment of se- quence stratigraphic framework, East-west strata distribution displays a character of thick east and thin west wedge, and the west of Suining-Lezhi-Ziyang lack in Xixiangchi Group. The development of reser- voirs within the sequence stratigraphic framework is significantly affected by sequence boundary, while the grain shoal facies that can form effective reservoirs are predominately distributed in highstand systems tract（HST）.

关 键 词：四川盆地 洗象池群 碳、氧同位素 频谱趋势分析 层序地层划分 层序格架 

分 类 号：P539.2[天文地球—古生物学与地层学]