湿润型风成沙丘沉积特征及沉积环境——以秘鲁马德雷德迪奥斯盆地三叠系—侏罗系下Nia组为例  

Sedimentary characteristics and sedimentary environment of moist eolian dunes: A case study of Triassic-Jurassic Lower Nia Formation in Madre De Dios Basin in Peru

作　　者：韩杰 张志伟[1] 赵永斌[1] 田作基[1] 阳孝法[1] 刘亚明[1] 马中振[1] HAN Jie;ZHANG Zhiwei;ZHAO Yongbin;TIAN Zuoji;YANG Xiaofa;LIU Yaming;MA Zhongzhen(PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《大庆石油地质与开发》2022年第5期9-19,共11页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油“十四五”前瞻性基础性重大科技项目“海外重点领域油气勘探关键技术研究”(2021DJ3105)。

摘　　要：风成沙丘作为重要的油气储层有着特殊的环境指示意义,其沉积特征及沉积环境研究对风成沙丘研究较为关键。通过对秘鲁马德雷德迪奥斯盆地下Nia组风成砂岩的露头资料、岩心资料及相关薄片资料进行分析发现,岩性为红色细粒长石砂岩或长石质石英砂岩,结构成熟度高,宏观露头发育风成交错层理及黏附结构,石英颗粒表面具有碟形撞击坑、红褐色铁质黏土套及硅质沉淀等风成特征,表明下Nia组为一套内陆沙漠风成沙丘沉积。针对岩性特征进一步总结出细粒砂岩、极细粒砂岩、泥质砂岩及细粒砂岩与泥质砂岩互层4类岩性组合,识别出丘间迁移界面与沙丘再活化面2类风成沙丘界面,并划分为沙丘及丘间2个亚相,组合成4个风成沙丘单元。结合湿丘间沉积特征认为下Nia组风成沉积长期受潜水面影响,发育与三叠纪—侏罗纪南美洲地区普遍湿润的古气候保持一致的湿润型风成沙丘沉积,湿润型风成沙丘既控制了极好物性的储层发育,也控制了分布广、沉积厚的风成沙丘堆积。研究成果为秘鲁地区下Nia组风成砂岩储层的整体勘探提供了理论支持。As an important oil and gas reservoir,eolian dune has special environmental indicating significance,studies on its sedimentary characteristics and sedimentary environment are crucial to eolian deposition research.Analyses on outcrops,core and thin-section data of Lower Nia Formation in Madre De Dios Basin in Peru show lithology of red fine-grained feldspar sandstone or feldspathic quartz sandstone with high texural maturity. Eolian cross bedding and adhesive structures are well-developed in macro-outcrops. Quartz grain surface has eolian characteristics of dish craters,red ferruginous clay edge and siliceous precipitation,indicating that Lower Nia Formation is a set of inland desert eolian deposition. 4 types of lithology association are further classified including finegrained sandstone,extremely fine-grained sandstone,argillaceous sandstone and interbedded sandstone and argillaceous sandstone. 2 types of eolian dune boundary are identified including interdune migration surface and dune reactivation surface,divided into 2 subfacies including dune and interdune,forming 4 eolian dune units. Integrated with moist interdune sedimentary characteristics,eolian deposition of Lower Nia Formation is considered as longterm affected by water table,with moist eolian deposition developed consistent with widely Triassic-Jurassic humid climate in South America. Moist eolian deposition not only controlled reservoir development with excellent physical properties and also controlled widely distributed and thick eolian sandstone deposition. The research provides theoretical support for overall exploration of eolian sandstone reservoirs in Lower Nia Formation in Peru area.

关 键 词：风成沙丘 沉积特征 沉积环境 三叠系—侏罗系 马德雷德迪奥斯盆地 秘鲁 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P534.5[天文地球—古生物学与地层学] P588.2123[天文地球—地质学]