珠江口盆地陆丰13东洼新生代构造演化与油气成藏特征

陆丰13东洼是珠江口盆地油气勘探的重点区域。结合区域构造背景，在精细解释高品质三维地震资料的基础上，对陆丰13东洼的洼陷结构和构造特征进行综合分析，并运用平衡剖面技术对洼陷的构造演化进行了恢复与研究，探讨了构造演化对圈闭形成与成藏的影响。研究结果表明：(1)陆丰13东洼新生代构造演化可划分为早—中始新世断陷、晚始新世断坳转换、渐新世—第四纪区域热沉降坳陷等3个阶段，其中断陷阶段具有完整的断陷旋回，根据断陷活动的强弱可进一步划分为断陷初始期、断陷高峰期、断陷萎缩期，断陷初始期和断陷萎缩期储层较为发育，断陷高峰期烃源岩较为发育。(2)在多期次构造活动的影响下，陆丰13东洼新生代形成了多种类型的圈闭，包括披覆背斜圈闭、断背斜圈闭、断块圈闭、断鼻圈闭、构造-地层圈闭（削截、超覆）、构造-岩性圈闭。众多的圈闭类型表明研究区油气勘探潜力巨大，特别是断陷阶段与断坳转换阶段沉积的文昌组和恩平组均发育大量各类型圈闭，且邻近优质烃源岩，成藏条件优越，是陆丰13东洼油气勘探的重点层系；平面上，南部缓坡带发育圈闭类型及数量最多，其次是中央隆起带与低凸起，均是研究区油气勘探的重要区带。

Tectonic evolution and hydrocarbon accumulation characteristics of Cenozoic in eastern Lufeng 13 subsag,Pearl River Mouth Basin

The eastern Lufeng 13 subsag is a key area for oil and gas exploration in the Pearl River Mouth Basin. Combined with regional tectonic background，and based on the fine interpretation of high-quality 3 D seismic data， the structure and structural features of the eastern Lufeng 13 subsag were analyzed，the tectonic evolution of the subsag was restored by using balanced section technology，and the influences of tectonic evolution on trap formation and hydrocarbon accumulation were discussed. The results show that: (1) The Cenozoic tectonic evolution in eastern Lufeng 13 subsag can be divided into three stages: Early-Middle Eocene fault depression，Late Eocene fault depression transition，Oligocene-Quaternary regional thermal subsidence depression. The fault depression stage has a complete fault depression cycle. According to the strength of the fault depression activity，it can be further divided into the initial stage，peak stage and shrinkage stage of the fault depression. The reservoirs were relatively developed in the initial stage and shrinkage stage of the fault depression，and the source rocks were relatively developed in the peak stage of the fault depression. (2) Under the influence of multi-stage tectonic activities，many types of traps were formed in Cenozoic in eastern Lufeng 13 subsag，including drape anticline traps， fault anticline traps，fault block traps，fault nose traps，structural-stratigraphic traps (truncation，overlap) and structural-lithologic traps. So many trap types show great potential for hydrocarbon exploration in this area，in particularly，the Wenchang Formation and Enping Formation，which are deposited in the fault depression stage and fault depression transition stage，have developed a large number of traps of various types. Those traps are close to high-quality source rocks and have favorable conditions for hydrocarbon accumulation，which are the key formations for oil and gas exploration in eastern Lufeng 13 subsag. In plane，the southern gentle slope zone has the most types and numbers of traps，followed by the central uplift zone and low uplift zone，which are the most important zones for hydrocarbon exploration in the study area.