松辽盆地南部大安地区姚一段层序地层格架与浅水三角洲沉积特征及演化  

Sedimentary characteristics and evolution of shallow⁃water delta in sequence stratigraphic framework of Member 1 of Yaojia Formation in Da’an area,south Songliao Basin

作　　者：何庆斌[1,2] 张继红 HE Qingbin;ZHANG Jihong(School of Petroleum Engineering,Northeast Petroleum University,Daqing 163318,China;Honggang Oil Production Company,PetroChina Jilin Oilfield Company,Songyuan 138000,China)

机构地区：[1]东北石油大学石油工程学院,黑龙江大庆163318 [2]中国石油吉林油田公司红岗采油厂,吉林松原138000

出　　处：《大庆石油地质与开发》2022年第6期1-12,共12页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项“松辽盆地致密油开发示范工程”(2016ZX05001-002);中国石油天然气股份有限公司科技项目“大中型岩性地层油气藏富集规律与关键技术”(2019B-0307)。

摘　　要：浅水三角洲沉积特征与演化是控制砂体形态、准确预测储层的关键。综合岩心、测井、地震等资料,在层序界面识别的基础上,结合小波系数曲线和时频色谱图建立姚一段等时地层格架,通过分析各层序单元内的沉积特征,明确基准面升降对沉积演化、砂体形态的控制。结果表明:姚一段为1个长期基准面上升半旋回,可分为3个中期旋回,MSC1主要发育基准面下降期的泥岩,MSC2和MSC3则发育基准面上升期的砂岩;研究区浅水三角洲分为2个亚相和4个微相,以三角洲前缘沉积最发育,仅东南部见少量前三角洲,水下分流河道、河口坝是研究区主要的砂体类型,呈片状展布的席状砂厚度薄、含油性差;姚一段在总体水进的背景下经历了早期基准面缓慢下降、中期基准面快速上升和晚期基准面缓慢上升3个演化阶段,基准面周期性升降形成的季节性河流控制了沉积相演化,是造成各层序单元内沉积相类型、砂体形态差异的重要原因。研究成果为松辽盆地南部大安地区姚一段难采储量的整体动用和高效开发提供了地质依据。Sedimentary characteristics and its evolution of shallow-water delta is key factor for controlling sandbody geometry and accurately predicting reservoirs.Based on sequence boundary identification by using core,logging and seismic data,isochronous stratigraphic framework of Member 1 of Yaojia Formation is established by combin‑ing wavelet coefficient curve and time-frequency chromatograms.Sedimentary characteristics in all sequence units are analyzed to determine control of base level fluctuation cycle on sedimentary evolution and sandbody geometry.The results show that Member 1 of Yaojia Formation is a long-term base level rising hemicycle,which can be divid‑ed in to 3 mid-term cycles.MSC1 mainly developed mudstone in base level descending period,while MSC2 and MSC3 developed sandstone in base level rising period.Shallow-water delta in studied area is divided into 2 sub-facies and 4 micro-facies,with delta front most developed and little pro-delta only in southeast area.Underwater dis‑tributary channels and estuary dam are the main sandbody types,while sheet sand with flaked extension has small thickness and poor oiliness.The evolution of base level cycle in Member 1 of Yaojia Formation has undergone 3 base level evolution stages including slowly subsidence in early stage,fast rising in middle stage and slow rising in last stage.Ephemeral stream formed cyclic by fluctuation of base level controlled sedimentary facies evolution,and is important cause for different sedimentary facies types and sandbody geometry in each sequence unit.The study provides geologic basis for integral exploration and efficient development of hard producible reserves in Member 1 of Yaojia Formation in south Songliao Basin.

关 键 词：浅水三角洲 沉积特征 小波分析 层序地层格架 姚一段 大安地区 松辽盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]