珠江口盆地陆丰13西北洼古近系构造沉积演化及资源潜力  

Tectonic and sedimentary evolution of Paleogene and resource potential in northwestern Lufeng13 sag,Pearl River Mouth basin

作　　者：朱文奇 黄胜兵 郭刚 陈凯 王升兰 柯岭 胡艳飞 ZHU Wenqi;HUANG Shengbing;GUO Gang;CHEN Kai;WANG Shenglan;KE Ling;HU Yanfei(CNOOC Research Institute Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《中国海上油气》2023年第2期13-22,共10页China Offshore Oil and Gas

基　　金：“十三五”国家科技重大专项“中国近海富烃凹陷优选与有利勘探方向预测(编号:2016ZX05024-002)”;中海石油(中国)有限公司综合科研项目“中国近海盆地潜在富油凹陷资源潜力、成藏机制与突破方向(编号:2021-KT-YXKY-03)”部分研究成果。

摘　　要：珠江口盆地陆丰13西北洼是一个生烃潜力尚未证实的洼陷,其是否发育有效烃源是勘探面临的首要问题。充分利用钻井、测井和三维地震资料,在洼陷结构解剖的基础上,对其古近系构造沉积演化、烃源岩发育条件和存在证据进行了深入分析。研究表明:①受多期构造运动影响,陆丰13西北洼古近系构造演化经历了强烈裂陷、弱裂陷、差异升降以及断拗转换4个阶段。②在不同的构造演化阶段,主受物源供给变化的影响,其古近系沉积充填经历了“文昌组先沉积,恩下段差异剥蚀,恩上段—珠海组区域再覆盖”的演化过程。③文下段沉积时期,由于控洼断层强烈伸展、火山大规模喷发以及物源供给相对有限,使得陆丰13西北洼文下段广泛发育半深—深湖相烃源岩,现今最大残留面积约107 km^(2),而且已经开始规模生烃,模拟总资源量约1.21亿方油当量,为一个潜在富生烃洼陷。The northwestern Lufeng13 sag in the Pearl River Mouth basin is a sag with unconfirmed hydrocarbon generation potential.The primary challenge for exploration is to find effective hydrocarbon source rock.In this paper,based on the structural analysis,the tectonic and sedimentary evolution of Paleogene,development conditions of source rock and its proof of presence in the northwestern sag of Lufeng13 depression were analyzed in depth by making the best use of drilling,logging and 3D seismic data.The study shows that,affected by multiple tectonic movements,the northwestern Lufeng13 sag has experienced four stages of tectonic evolution during Paleogene:strong rifting,weak rifting,differential uplift and subsidence,and faulted sag-depression transformation.At different stages of tectonic evolution,the Paleogene sedimentary filling in the northwestern sag of Lufeng13 depression went through the following sequences of evolution:deposition of WC Formation,differential erosion of lower EP Formation,and finally the regional deposition of upper EP Formation and ZH Formation as a result of the variation in sediment supply.During the deposition of the lower WC Formation,due to the intense extension of sag controlling faults,large-scale volcanic eruption and relatively limited sediment supply,semi-deep to deep lacustrine source rocks were widely developed in the northwestern Lufeng13 sag.The current maximum residual area of the source rock is about 107 km^(2),where large-scale hydrocarbon generation has started.The total resource is about 121 million cubic meters of oil from the simulation,which indicates that the northwestern sag of Lufeng13 depression is a potential hydrocarbon rich depression.

关 键 词：洼陷结构 构造沉积演化 烃源岩 资源潜力 陆丰13西北洼 珠江口盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]