南阳凹陷黑龙庙地区近岸水下扇沉积特征研究

为了明确黑龙庙地区近岸水下扇沉积特征及空间演化规律，通过岩芯观察、测井、分析化验及高精度三维地震资料的分析，对研究区的扇体进行研究。结果表明，研究区岩性主要为砂砾岩、砾状砂岩、含砾砂岩、细砂岩。沉积物孔隙类型以砾内溶孔、晶间孔为主，发育块状层理、冲刷面、暗色泥岩撕裂屑、液化构造等反映重力流沉积的构造，此外，也可见小型交错层理、水平层理、板状交错层理等反映牵引流的沉积构造。沉积体划分为扇根、扇中、扇端亚相，其中，扇中辫状水道物性最好，能为油气提供良好的储集条件。黑龙庙地区核桃园组二段可划分为3个亚段，各亚段扇体的发育受基准面升降控制，整体表现出进积型与退积型扇体叠合发育的沉积演化模式。

Sedimentary Characteristics of Nearshore Subaqueous Fans in the Heilongmiao Area of the Nanyang Sag

To determine the sedimentary characteristics and spatial evolution of nearshore subaqueous fans in the Heilongmiao Area,core observation,logging,laboratory analysis,and high-precision 3D seismic data analyses were performed.The lithology of the study area was mainly comprised of glutenite,gravel sandstone,pebbly sandstone,and fine sandstone,with major sediment pore types of intra-grain dissolved pores and intercrystalline pores.Gravity flow deposition structures were reflected by the blocky bedding,flushing surface,torn fragments of dark mudstone,liquefied structures,and sedimentary structures formed by traction flow,and we also found deposition structures of small-scale cross-bedding,horizontal bedding,and slab-like crossbedding.The sediments were divided into subphases of fan roots,fan body,and fan-end.Among them,the braided channel in the fan body exhibited the best physical properties and provided good reservoir conditions for oil and gas accumulation.The second section of the Hetaoyuan Formation in the Heilongmiao Area was divided into three subsegments.The development of the fans in each subsegment was controlled by the datum level change,and the overall sedimentary evolution model showed a superimposed fan development of progradation and regression.