松辽盆地长岭断陷断层特征及其控油气作用

松辽盆地长岭断陷发现了多种类型的油气藏，不同构造区带油气藏类型及规模差异较大。基于地震资料解释分析，对长岭断陷的不同构造区带的断层特征、断层形成机制及活动性质开展了研究，结合勘探实践，探讨了断层对长岭断陷油气成藏的控制作用，指出了不同构造区带的重点勘探方向。长岭断陷发育断陷期、拗陷期及反转期3期不同性质的断层，断层形成机制为在北北东向左行拉张走滑的应力背景下，产生次级的北东向（P剪切）、南北向-北北西向（R剪切）以及北西向（T破裂）断层。不同构造区带的断层活动有较大差异，断层对长岭断陷烃源岩分布、相关圈闭的形成以及油气运移和调整有重要的控制作用，在构造定型早、拗陷期断层活动微弱的地区，原生油气藏保存较好，要注重下白垩统火石岭组、沙河子组、营城组原生油气藏的勘探。而在断层活动持续时间长，尤其是存在反转的深大断层及走滑断层地区，次生油气藏是重要的勘探方向。

Fault characteristics and controls on hydrocarbon accumulation in Changling Faulted Depression,Songliao Basin

Multiple types of oil and gas reservoirs have been found in the Changling Faulted Depression, and the reservoir types and pool size are variable in different areas. Fault characteristics, forming mechanisms and activity periods were studied based on seismic interpretation. The fault controls on hydrocarbon accumulation were discussed, and the main exploration targets in different areas were identified. Three types of fault were formed during the fault, depression and inversion periods. Under a NNE direction sinistral strike-slip and tension stress background, many NE, NS-NNW and NW direction secondary faults were generated. The fault activity characteristics varied in different areas. Due to fault activities, multiple types of structural traps were formed. The faults have a great influence on oil and gas migration and accumulation in the Changling Faulted Depression. In the areas that the faults are inactive and the tectonics are stable during the depression and the inversion periods, primary reservoirs were well preserved. As a result, the primary reservoirs in the Huoshiling, Shahezi and Yingcheng formations are main exploration targets. The secondary reservoirs are important exploration directions for the long duration of fault activity, especially in the deep faults and strike-slip faults.