准噶尔盆地沙湾凹陷滩坝砂的发现及油气勘探潜力

近期准噶尔盆地沙湾凹陷ST1井上乌尔禾组获得重大突破,其具有典型的滩坝砂沉积特征,揭示其成藏地质特征与玛湖凹陷有显著差别。为了探索油气勘探新领域,落实滩坝砂平面分布及油气勘探潜力,以高分辨率三维地震资料为基础,结合钻井、试油、测井、岩心等数据,同时利用属性提取、沿层切片等地震技术,精细刻画了沙湾凹陷上乌尔禾组滩坝砂平面展布特征,并探讨了其油气成藏潜力。结果表明:研究区目的层滩坝砂沉积特征明显,沿湖岸线成带状分布;油气成藏条件优越,勘探潜力大。滩坝砂沉积相带的发现及落实,为沙湾地区滩坝砂油气藏勘探提供了地质模型参考,同时为准噶尔盆地玛湖大油田的拓展提供了新的勘探领域。

Discovery and hydrocarbon exploration potential of beach-bar sand in Shawan Sag,Junggar Basin

Recently,well ST1 in Shawan Sag of Junggar Basin has achieved major breakthrough in Upper Urho Formation,of which the geological characteristics regarding hydrocarbon accumulation and reservoir forming are clearly different from those in Mahu Sag,and present typical features of beach-bar sand deposition.In order to explore a new field of hydrocarbon exploration,confirm the planar distribution and exploration potential of beach-bar sand,on the basis of high-resolution three-dimensional seismic data,combined with data collected during drilling,formation testing,well logging and core analyses,the plane distribution characteristics of beachbar sand of Upper Urho Formation in Shawan Sag were depicted by using seismic techniques such as attribute extraction and stratal slicing,and its hydrocarbon accumulation potential was discussed.The results show that the target layer in the study area presents apparent characteristics of beach-bar sand,which is band-shaped distri-buting along the lake shoreline,and it forms good hydrocarbon accumulation conditions and has a huge area for exploration.The discovery and confirmation of the beach-bar sand field provides a model to shed light on the exploration of beach-bar sand oil and gas reservoir across the Shawan Sag,as well as a new exploration field for the"Greater Mahu"area in Junggar Basin.