塔里木盆地哈得逊隆起的发现及其勘探意义

DISCOVERY OF HADEXUN UPLIFT IN THE TARIM BASIN AND ITS SIGNIFICANCE IN OIL EXPLORATION

哈得逊隆起是新近在塔里木盆地满加尔凹陷西部发现的一个向西南抬升、向北东方向倾伏的大型宽缓鼻状隆起 ,隆起构造主要发育在石炭系以上层位 ,以石炭系较为典型。构造演化史分析表明 ,哈得逊地区在前侏罗纪属于轮南古隆起的一部分 ,二者统一为一向西南倾伏、向北东抬升的大型古隆起构造 ,与现今哈得逊隆起的倾伏方向恰好相反。三叠纪末印支运动后 ,南抬北倾的哈得逊隆起开始形成。晚第三纪以来 ,满西地区石炭系地层也由区域南倾反转为区域北倾 ,并形成石炭系鼻状隆起。在石炭系地层发生翘式反转的过程中 ,哈得逊地区因正好处于翘倾运动的“支点”位置 ,构造位置适中 ,构造作用也相对比较稳定 ,因而对于油气聚集和保存十分有利 ,是满西地区寻找大中型油田最有利的地区。

The Hadexun uplift,discovered recently,is a large,wide,gently dipped nose shaped one plunging northeastward,which located at the western Manjiaer Depression in Tarim Basin.It was mainly developed in the Upper Paleozoic and Meso Cenozoic horizons,particularly in the Carboniferous.Analyses of tectonic evolution revealed that the Hadexun uplift was a part of the Lunnan paleo uplift during the period of pre Jurassic,which is an ancient one pitching southwestward,just opposite to the pitching direction of Hadexun uplift.The Hadexun uplift was not formed until the end of Triassic when the strong Indo China tectonic movement occurred.Therefore,a preliminary form of the present Hadexun uplift appeared in the Jurassic and was more obvious in the Cretaceous.Nevertheless,it is only up to the Neogene that the Carboniferous strata in the western Manjiaer region were reversed from southwestward dipping to northeastward and the present Carboniferous uplift was finally formed.Being located at the 'fulcrum'site in the course of the Carboniferous reversing movement,the Hadexun area has been a moderate high and relatively stable tectonically,which is extremely favorable to oil accumulation and preservation in the region.Therefore the Hadexun area is considered to be the most favorable exploration region in the west Manjiaer Depression.The newly found Hade 4 oilfield is just located at this area.