CAJ | 학술논문

中央峡谷是平行于陆坡跨盆地发育的深水水道-天然堤体系。应用2D和3D地震数据，结合岩心和测录井资料，分析了琼东南盆地中央峡谷充填的岩性、砂体类型和特征、分布规律及控制因素。认为距今10.5～4.2 Ma期间，琼东南盆地中央峡谷内发育5期次级水道充填，沉积了浅灰色砾质细砂岩、厚层块状/粒序细砂岩、粉砂岩和灰黑色粉砂质泥岩、泥岩等，发育4种充填相，包括浊流、碎屑流、滑塌等重力流过程和半深海沉积。应用井-震对比并结合均方根振幅属性分析，识别出4种砂体类型，分别为峡谷轴部砂体、天然堤砂体、侧向加积砂体和侵蚀残余砂体。砂体类型在纵向上的分布具有分异性特征，即峡谷充填总体在底部-中部以砂岩为主，上部由粉砂岩构成，在不同次级峡谷充填内，同样是砂岩在下，向上渐变为粉砂岩的正旋回特征。另外，砂体在横向上的分布具有分段性特征，第1-3期峡谷充填砂体，主要发育在峡谷中游；第4、5期充填砂体仅发育在峡谷中上游。中央峡谷充填砂体分布主要受母源区岩性、长距离及多次搬运、初始流体规模及流态、次级水道的改造与破坏、中央峡谷发育方式和盆地构造等因素控制。
중앙협곡시평행우륙파과분지발육적심수수도-천연제체계。응용2D화3D지진수거，결합암심화측록정자료，분석료경동남분지중앙협곡충전적암성、사체류형화특정、분포규률급공제인소。인위거금10.5～4.2 Ma기간，경동남분지중앙협곡내발육5기차급수도충전，침적료천회색력질세사암、후층괴상/립서세사암、분사암화회흑색분사질니암、니암등，발육4충충전상，포괄탁류、쇄설류、활탑등중력류과정화반심해침적。응용정-진대비병결합균방근진폭속성분석，식별출4충사체류형，분별위협곡축부사체、천연제사체、측향가적사체화침식잔여사체。사체류형재종향상적분포구유분이성특정，즉협곡충전총체재저부-중부이사암위주，상부유분사암구성，재불동차급협곡충전내，동양시사암재하，향상점변위분사암적정선회특정。령외，사체재횡향상적분포구유분단성특정，제1-3기협곡충전사체，주요발육재협곡중유；제4、5기충전사체부발육재협곡중상유。중앙협곡충전사체분포주요수모원구암성、장거리급다차반운、초시류체규모급류태、차급수도적개조여파배、중앙협곡발육방식화분지구조등인소공제。
The central canyon is a deep-water channel-levee system developed in parallel to the slope across Qiongdongnan Basin.Thisstudy investigated depositional filling characteristics of central canyon in terms of the lithological compositions,the types of sand bodies,the patterns of reservoir distribution,and the controlling factors using 2D/3D seismic data combined with core,drilling and well-loggingdata.The results show that during the period of 10.5-4.2Ma,the canyon was filled with five-stage secondary channels and depositedwith light-gray gravelly fine sandstone,massive and graded fine sandstone,siltstone,dark-black silty mudstone,and mudstone.Fourtypes of depositional filling were developed with hemiplegic deposits and gravity flow of turbidity currents,debris,and slumps.Basedon well-seismic calibration and root-mean-square seismic attribution analysis,four types of sand body were identified in the canyon,in-cluding canyon-axis sand bodies,natural levee sand bodies,lateral accretion sand bodies,and erosion residual sand bodies.These sandbodies show distinct variations in the vertical distribution.The canyon is mainly filled with sandstone in the bottom to middle part andsiltstone in the upper part,with similar characteristics of positive cycles in the secondary fillings.Additionally,the sand bodies showsegmented distribution horizontally.Stage 1-3 fillings of sandstone are distributed mainly in the middle reaches of the canyon,whilestage 4 and 5 fillings of sandstones are mainly in the middle-upstream.Major factors controlling the distribution of sand bodies in thecanyon include lithological composition of the provenance,distant and multiple transports,scale and flow pattern of initial gravity flows,destruction and reconstruction of secondary channels,development mode of the canyon,and tectonic framework of the basin.