川西坳陷SDG地区浅水三角洲沉积特征及沉积成因模式  

Sedimentary characteristics and sedimentary genetic models of shallow water delta in the SDG area,west Sichuan Depression

作　　者：陈佩佩[1] 胡望水[1] 黄鑫 邓美洲[3] CHEN Peipei;HU Wangshui;HUANG Xin;DENG Meizhou(Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan City,Hubei Province,430100,China;Shanghai Branch,CNOOC,Shanghai City,200000,China;Institute of Oil and Gas Evaluation,SINOPEC Southwest Branch,Chengdu City,Sichuan Province,610000,China)

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [2]中海石油上海分公司,上海200000 [3]中国石化西南油气分公司评价所,四川成都610000

出　　处：《油气地质与采收率》2018年第2期20-28,共9页Petroleum Geology and Recovery Efficiency

摘　　要：四川盆地川西坳陷SDG地区沉积特征复杂,对其沉积相的解释尚存许多争议。根据SDG地区313口井的测井和录井资料、25口取心井的岩心和分析化验等资料,在构造和沉积背景控制下通过稳定重矿物以及岩屑组合确定沉积物来源,对岩相类型及其成因进行解释,并结合前人研究成果对典型浅水三角洲的沉积识别标志和特征进行剖析,采用"点—线—面—体"的研究思路对沉积演化规律进行总结,进而建立研究区浅水三角洲的沉积成因模式。研究结果表明,SDG地区具有形成浅水三角洲的有利地质条件。其砂岩粒度细、分布广泛,单层砂体薄且规模小,粒度概率累积曲线表现为较强的牵引流作用特点,发育特征性的岩相组合,沉积砂体在(水下)分流河道两侧及前方整体具有明显的河控性特征,且具有典型的河道改造特征。针对研究区浅水三角洲提出5种沉积成因模式,即三角洲平原"河控带状体"模式、三角洲前缘"河控带状体"模式、三角洲前缘"河控河口坝"模式、三角洲前缘—前三角洲过渡带"浪控席状砂"模式以及三角洲前缘"浪控远砂坝"模式,其中三角洲前缘"浪控远砂坝"模式是针对SDG地区首次提出。Abstract:The interpretation of sedimentary facies remains controversial since the sediment is complex in the SDG area,west Sichuan Depression,Sichuan Basin.Considering the complex sedimentary characteristics in the Penglaizhen Forma-tion of the SDG area,the sediment provenance direction was determined under the control of structure and sedimentary background through analyzing the stable heavy mineral and rock debris combination based on cores and measurements re-sults from 25 cored wells and logging data of 313 wells.On this basis,the lithofacies type and their genetic environments were interpreted.Combined with the previous research results,the typical characteristics and identification marks of shal-low water delta were dissected and then the sedimentary evolution characteristics were summarized to establish the sedi-mentary genetic model of shallow water delta based on the principle of“point-line-plane-volume”.The study results show that the SDG area has favorable geological conditions for the formation of shallow water delta,and the sand is characterized by fine granularity and wide distribution,but the single sand body is thin and small.The cumulative probability curves of granularity shows that the deposition was controlled by traction current which results in typical lithofacies combinations,and the deposited sand bodies have obvious fluvial-dominated characteristic at both sides of(underwater)distributary channels and their front,and the channel was reformed obviously.Based on the further exploration of sedimentary charac-teristics and sedimentary facies,five kinds of sedimentary models were put forward for shallow water delta,which are the model of fluvial-controlled blocky sand in delta plain,the model of fluvial-controlled blocky sand in delta front,the model of fluvial-controlled debouch bar in delta front,the model of tide-controlled sheet sand in delta front-prodelta transition zone and the model of tide-controlled far sand bar in delta front,and the model of tide-controlled far sand bar in delt

关 键 词：浅水三角洲 沉积特征 沉积成因模式 蓬莱镇组 SDG地区 川西坳陷 

分 类 号：TE112.221[石油与天然气工程—油气勘探]