塔里木盆地巴东4构造与油气

Structure and Hydrocarbon of the Badong in Tarim Basin

研究区位于塔里木盆地西北部,跨越巴楚断隆和阿瓦提坳陷两个构造单元。巴东 4 构造位于研究区的东南部,由 3 个背斜高点共同构成,总体轴向呈北西向延伸。该构造中的低角度坡坪式逆断层BD4DF、BD4D1F形成于中寒武世-泥盆纪,自古近纪开始又发生活动。低角度坡坪式逆断层 BD4SF和高角度逆冲走滑断层BF3、BF1 1都开始形成于古近纪,其中断层BD4SF和BF3在第四纪之前停止活动,但断层BF1 1至今仍处于活动状态。巴东4构造自古近纪开始受到走滑断层 BF3、BF1 1 切割,并且上述断层曾有过“通天”的历史,不仅使同构造期生成的油气没有得到保存,而且使早期形成的古油气藏受到破坏。

The research area is situated in the northwestern part of Tarim basin and covers the Bachu block uplift and Awati depression. The Badong 4 structure is situated in the southeastern part of the research area and consists of 3 structural highs of anticlines generally oriented in northwest direction. The low angular step shape thrusts BD4DF、BD4D1F were formed during middle Cambrian period to Devonian period and have been activated again since Palaeogene period. The low angular step shape thrust BD4SF and high angular dextral reversed strike-slips BF3、BF1-1 begin to be formed since Palaeogene period. While BD4SF, BF3 stop activation before Quaternary period, fault BF3 remains activated from Palaeogene to now. Badong 4 structure have been dissected by faults BF3 and BF1-1 since Palaeogene period. The faults BF3, BF1-1 once emerged on the Earth’s surface. It is for this reason that not only the syntectoic hydrocarbon formed during its emergence time was not preserved, but the oil and gas accumulation formed during middle Cambrian period to Devonian period was lost also.