准噶尔盆地车排子凸起新近系“网毯式”成藏机制剖析及其对盆地油气勘探的启示

Analysis on Meshwork—carpet Pool-forming Mechanism of Chepaizi Uplift and Enlightenment on Petroleum Exploration of Junggar Basin

与油气通常近源聚集不同,准噶尔盆地西部车排子凸起新近系为特殊的远源成藏。其成藏的机制是什么?是否具有普遍性?如何进行勘探?本文从其充注特征和输导体系入手,剖析了成藏机制与富集特征,进而系统描述评价了准噶尔盆地宏观输导格架,预测此类油气藏的勘探潜力与有利方向。研究表明,车排子凸起新近系远源成藏是"网毯式"体系高效输导的结果,准噶尔盆地多期构造运动与"砂-泥二元结构"沉积背景促使普遍发育网毯式输导体系。网毯输导体系控制了准噶尔盆地50%以上数量的油气聚集,网毯式成藏是盆地内一种非常重要的成藏类型。毯-源关系表现为侧向或纵向直接沟通样式、断层沟通或接力样式、断层-中转层接力样式、断层-不整合接力样式等4种样式。分析毯-藏空间关系,存在毯边、毯尖、毯中削截、毯中背斜、毯中坡折、毯中断块、毯上断块、毯上岩性、毯上地层等9种毯砂油气藏与毯上相关油气藏类型。准噶尔盆地网毯式油气藏具有很大的勘探潜力,应重视并采取以网毯输导体系刻画评价为核心的研究与部署思路,大力推进此种类型油气藏的勘探。

Usually oil and gas are near the source, but the Neogene reservoir in the Chepaizi Uplift, the western Junggar Basin, behaves a special distance-source gas accumulation. what is the reservoir forming mechanism？ Is it universal？ And how to explore it？ By means of the hydrocarbon charging characteristics and petroleum passage system , the accumulation mechanism and enrichment characteristics are analyzed.And then,the paper gives a systematic description and evaluation on the macroscopic transportation frame of the Junggar Basin, forecast the exploration potential and the advantageous exploration direction of this kind of reservoir finally. The research shows that the far source long range accumulation of Neogene Chepaizi Uplift ascribes the efficient meshwork-carpet passage system which was commonly developed owing to the driving force of multiphase tectonic movement and ＂sand-mud binary structure＂ depositional setting in the Junggar Basin. The meshwork-carpet passage system controlls more than fifty percent of the oil-gas accumulation and become a very important pool forming type in the Junggar Basin. ＂Carpet-source＂ relationship presents four different styles （lateral or vertical direct linked style, fault linked or relay style, fault transit layer relay style, fault-unconformity relay style ） . ＂Carpet- reservoir＂ spatial relations presents consists nine types of distribution type （carpet edge, carpet tip, truncation of central carpet, anticline of central carpet, slope break of central carpet, fault block of central carpet, fault block above carpet, lithology above carpet , strata above carpet ）. Meshwork-carpet reservoir type of the Junggar Basin has a substantial exploration potential, which should be paid great attention to. The research and the strategic plan should be preceded with the description and evaluation of the meshwork-carpet oil and gas passage system at the core position to popularize the exploration of this type of reservoir.