Through the dissection of typical subtle oil and gas reservoirs in the southern slope of Kuqa Depression,the structure,sedimentological conditions,trap development types and models of subtle traps were sorted out,and the exploration direction was pointed out. The results show that:（1）Three types of subtle traps are mainly developed in the southern slope belt of Kuqa Depression,including stratigraphic overlap trap,sandstone updip pinchout lithologic trap and fault lithologic compound trap.（2）Two types of traps are developed in Xinhe and adjacent areas:sandstone updip pinchout traps formed by structural tilting after sedimentation and large-scale fan delta stratigraphic overlap trap developed under the control of ancient uplift,and sandstone updip pinch out trap is the main exploration target in the next step.（3）At the top of Bashijiqike Formation,a lacustrine transgressive systems tract was developed,and lacustrine transgressive mudstone separated multidirectional source systems,which can form large-scale lithologic traps. The Triassic source rock has reached mature to high mature evolution stage in Xinhe area. The“dual source hydrocarbon supply”system provides sufficient oil and gas sources for subtle oil and gas reservoirs in this area,which has great exploration potential.

在山前带地震勘探中通常应用叠加速度进行变速成图,但对近地表砾岩如何影响下伏地层叠加速度的研究较少,也缺乏有效的叠加速度校正方法.应用楔状模型模拟近地表砾岩特征,对不同位置处地震波走时—入射角曲线特征进行分析,并以库车山前带YKB地区为例,开展地震正演进行验证,证实了近地表高速砾岩会导致砾岩尖灭点之下形成异常高的叠加速度,使速度由扇根到扇端方向出现"低—高—低—高"的横向变化.基于此认识通过速度趋势线法校正叠加速度,并与井速度约束法进行了成图对比,结果揭示:由速度趋势线法得出的构造图地层产状与实测结果更接近、深度误差更小,证明了该方法在低勘探程度的山前带近地表砾岩发育区的有效性.

塔里木盆地碎屑岩油藏类型多,有低幅度构造、地层-岩性构造,识别含油气构造地震响应特征至关重要.根据目的层厚度、速度等方面建立不同的地质模型,进行地震正演模拟,建立含油气构造地震波场正演特征.分析对比正演模拟剖面和实际地震剖面的波场特征,结合地质资料,推测含油气范围,有效指导了井位部署.

The Carboniferous Kalashayi formation of the Tahe oilfield is one of the important oil-bearing series.Kalashayi formation has the following characteristics:thin sand(3~8m),change drastically in lateral direction,"one sand with one reservoir,one well with multiple reservoirs".In addition,the difference of wave impedance of sand and shale is small;the response of reservoir is submerged and the boundary of the trap is difficult to describe.In the case that vertical resolution can't meet the needs of the forecast,multiple solutions of prediction are reduced by the combination of multiple attributes through the processing of extending frequency and shifting phase and the application of seismic sedimentology method to fully tap the lateral resolution property of the plane.At the same time,the Carboniferous Kalashayi formation is subdivided into three trap types:structure lithology,channel lithology and stratigraphic type on the unconformity surface.Through technical research on the development of different types of traps,the corresponding method is established,which provides technical support for the fine exploration of Carboniferous Kalshayi formation and obtains the good application.

塔河油田石炭系卡拉沙依组是重要含油层系之一,储层厚度薄(3-8m),横向变化快,对比追踪困难,储层的空间展布是制约勘探开发的关键问题,本次研究以桑塔木工区高分辨率资料为基础,以卡拉沙依组V砂组为主要研究层段,通过岩石物理分析、正演模拟、去砂试验建立砂体地震识别模式,采用拓频及相移等特殊处理突出砂体响应特征,通过多属性融合、反演预测有利砂体展布,最后结合构造、断裂落实有利的构造—岩性圈闭,取得了良好的应用效果.