阜东斜坡芦草沟组岩相组合特征及展布规律  

Characteristics and Distribution of Lithofacies Assemblages of the Permian Lucaogou Formation in the Eastern Slope of Fukang Sag

作　　者：潘进 刘新龙 李辉[1] 刘超威 李树博 陈洪[1] 王泽胜[1] 李宗浩[1] 金腾瑞 陈美玲 朱新亭 樊向东[1] PAN Jin;LIU XinLong;LI Hui;LIU ChaoWei;LI ShuBo;CHEN Hong;WANG ZeSheng;LI ZongHao;JIN TengRui;CHEN MeiLing;ZHU XinTing;FAN XiangDong(Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石油新疆油田公司勘探开发研究院,新疆克拉玛依834000

出　　处：《沉积学报》2023年第5期1366-1379,共14页Acta Sedimentologica Sinica

基　　金：中国石油天然气股份有限公司“十四五”基础性前瞻性重大科技项目(2021DJ0405)。

摘　　要：准噶尔盆地阜康凹陷进入深层油气勘探阶段后,在芦草沟组首次钻遇厚层砂砾岩,打破了凹陷区芦草沟组储层不发育、整体为细粒沉积的认识。现阶段的油气勘探迫切需要对芦草沟组岩相的类型特征与展布规律开展系统研究。通过岩心、薄片、录井、测井资料对阜康凹陷芦草沟组砂砾岩储层的岩石学特征与岩相类型进行识别和区分,并对岩相在垂向和横向上的叠置类型及影响因素进行研究。结果表明,阜东斜坡芦草沟组纵向发育一套湖侵背景下的退积序列,下部发育粗粒碎屑岩,包含砂质细—中砾岩、含砾中—粗砂岩、细砂岩,其中砾岩的母岩以凝灰岩为主,砂岩的长石和岩屑含量较高,岩屑以火山岩岩屑为主,芦草沟组上部主要发育泥质粉砂岩和泥岩,厚度大,晚期湖泛泥岩盖层覆盖在早期低位域砂砾岩储层之上,具备形成岩性油气藏的条件。平面上西泉鼻隆北翼、南翼分别发育陡坡近岸水下扇与缓坡辫状河三角洲沉积体系,北翼砂砾岩分选差、砾石颗粒呈棱角状且定向性差、杂基颗粒支撑,呈现搬运距离近、水动力强、重力流沉积的特点,南翼砂砾岩分选好、颗粒支撑且具一定定向性,牵引流特征明显。该区岩相特征及展布规律受控于晚石炭世—早二叠世火山活动、鼻隆南北两翼石炭系顶界古地貌坡度变化、气候条件以及湖平面升降变化。After the exploration of deep oil and gas in the Fukang Sag,eastern Junggar Basin,a thick-bed conglomer⁃ate was drilled for the first time in the Lucaogou Formation,which disproved the previously held belief that the Lucao⁃gou Formation reservoir was not developed and the whole deposit was fine grained.At present,the systematic study of the lithofacies types,assemblage characteristics and distribution rules of the Lucaogou Formation is urgent for future oil and gas exploration.Based on core,thin section,and logging data,the petrological characteristics and lithofacies types of the conglomerate reservoir in the Lucaogou Formation were identified and distinguished,and the distribution law of lithofacies was predicted.Results showed that the Lucaougou Formation developed longitudinally due to a lake invasion retrogradation sequences,several main development coarse clastic rocks.The upper Lucaogou Formation pri⁃marily contains argillaceous siltstone and mudstone,The thickness is relatively large,and the late mudstone cap overlies the early low region conglomerate reservoir,forming a lithologic reservoir.North and south of Xiquan uplift,a braided river delta sedimentary system was developed,with a steep near-shore subaqueous fan and gentle slope,re⁃spectively.The north wing has poor conglomerate sorting,angular gravel particles with poor orientation,and hetero⁃basic particle support,exhibiting characteristics of short transport distance,strong hydrodynamic force,and gravity flow deposition.The south wing has good sorting,particle support with certain orientation,and obvious traction flow characteristics.Based on comprehensive analysis,the lithofacies characteristics and distribution were found to be controlled by the Late Carboniferous and Early Permian volcanism,with a paleogeomorphic slope of the Carbonifer⁃ous top boundary north and south of the Xiquanbi uplift,and fluctuation of the lake plane.

关 键 词：准噶尔盆地 阜康凹陷 芦草沟组 岩相组合 沉积模式 

分 类 号：P618.13[天文地球—矿床学]