呼图壁至乌苏一带新构造变形特征及油气勘探方向预测

THE ANALYSISOF NEOTECTONIC DEFORMATION FEATURES AND PREDICTION TO PETROLEUM POTENTIAL FOR EXPLORATION ALONG HUTUBI TO WUSU

以覆盖北天山山前呼图壁至乌苏一带的四景 L andsat TM卫星遥感图像的地质解译为基础 ,结合野外实地考察所获取的地质资料以及烃源岩的生烃和排烃的盆地模拟分析结果 ,对呼图壁—乌苏地区第二、三排构造带上新世以来的新构造运动变形特征、背斜和断裂构造的形成时代以及油气勘探方向进行分析和预测。该区第二、三排背斜构造的变形非常强烈 ,它们的构造变形始于上新世末期 ,早更新世末期是新构造变形最强烈的时期 ,这些背斜构造带在中更新世早期已基本形成。第二排背斜构造带的构造变形强于第三排构造带。有利烃源岩安集海河组的排烃高峰期在距今 0 .3Ma左右 ,晚于背斜构造的形成时期 ,其生成和排出的油气很有可能聚集于这些背斜构造中。发育于背斜构造核部或北翼一侧的逆冲断裂构造为油气的垂向运移提供了良好通道 ,但也可能导致油气的逸散和破坏。综合分析表明第三排背斜构造带中的西湖背斜、独南背斜。

Based on the geologic interpretation of landsat TM images covered the southwestern margin of Junggar basin,and intergated with the geologic data obtained from the field survey and the resuts of BSS[JGI] simulation for hydrocarbon generation and expulsion of source rocks,this paper analyses the neotectonic defromation character of the second and third row thrust- fold zone since the end of Pliocene,formation age of anticline and thrust structures,and the relationship of neotectonic movement with oil and gas.The research results show that neotectonic deformation of the second and third row anticline zone is very intensive,their deformation starts in the end of Pliocene,the neotectonic deformation is the most intensive in the end of early Pleistocene,the second and third row anticline zone has formed by the early stage of middle Pleistocene,the peak time of hydrocarbon expulsion for the favorable source rock- Anjihaihe Fm.is later than the formation age of these anticlines.The oil and gas from Anjihaihe Fm.is probably accumulated in these anticlines.The thrust faults usually develop near the core or in the northern limb,on the one hand,they provide the pathway for vertical migration of oil and gas,on the other hand,they also cause the loss and destruction of oil and gas. The certain attentions should be paid to the anticlines of the third row anticline zone,such as Xihu anticline, Dunan anticline,Anjihai anticline and Hutubi anticline,because they have good structural condition for oil and gas accumulation and preservation