辽河断陷盆地西部凹陷西斜坡齐欢地区同生断层发育特征及其控制作用

 辽河坳陷西部断陷西斜坡齐欢地区同生断裂十分发育,为弄清断层与构造、储层和油藏的关系,研究了该区同生断层发育特征及其控制作用。沙三段至东营组时期,该区发育了一系列的顺凹陷方向倾斜及滑动的同生正断层,断层产状呈铲式,走向为北东向,其控制了区域构造格局。分析了同生断层的生长指数与圈闭类型的关系,认为断裂活动越强,越利于形成局部构造。同生断层下降盘往往是滚动背斜、断鼻等局部构造和砂体发育区域,也是油气聚集的有利地区。同生断层附近往往井网控制程度低,剩余油富集,是老区挖潜剩余油的有利目标区域。

Reservoir control of contemporaneous faults in Qihuan Area of Western Slope in the western depression of Liaohe River Rifted Basin

The contemporaneous faults are well-developed in the Qihuan Area of the Western Slope in the western depression of the Liaohe River Rifted Basin. Therefore, one should study the development characteristics and the control of these faults in order to make clear how these faults can influence the structures and reservoirs. These contemporaneous normal faults, characterized by the north-east strike listric faults tilting and sliding in the direction of sag, control the regional structure patterns. Furthermore, from the 3D seismic data, the contemporaneous fault growth index is computed. The relations between the fault growth index and the trap types are analyzed. Finally the general conclusion for this area is that the more intense the fault tectonic activity is, the more advantageous for the formation of local structures. The rollover anticline and the fault nose always develop in a down-dropped block of contemporaneous faults, and these areas are in favour of the hydrocarbon accumulation because of the fine sand distribution in these structures. The conventional well pattern of the oil development is not effective near the contemporaneous faults as their down-dropped block may be overlooked. The research of the contemporaneous faults shows that the areas near these fault down-dropped block have also the potential prospects of the existence of residual oil.