基于构造应力场数值模拟的复杂断块油藏低级序断层预测——以南堡凹陷M区为例

针对低级序断层地震资料的多解性，通过构造解析，在确定低级序断层发育时期和构造背景的基础上，对南堡凹陷M区馆陶期构造应力场进行了数值模拟；并以岩石破裂准则为依据，用最小主应力解释了低级序断层的优势发育地区，用平面剪应力解释了低级序断层的优势走向，用剖面剪应力解释了低级序断层的优势视倾向，预测了低级序断层的发育规律。研究结果表明，南堡凹陷M区三级断层活动具有明显的分段性和分期性特点；在区域性南北向拉张和火山喷发造成的局部拱升的共同作用下，研究区中部为东一段低级序断层发育的优势区，发育近北西走向和近北东走向两组低级序断层，东部主要发育一组近北东走向的低级序断层，西部主要发育一组近北西走向低级序断层，断层视倾向以北倾为主。 

FORECAST OF LOWER ORDER FAULTS IN COMPLEX FAULT BLOCK RESERVOIRS BY NUMERICAL SIMULATION OF TECTONIC STRESS FIELD: TAKING M AREA IN NANPU SAG AS AN EXAMPLE

The tectonic stress field of Guantao formation is simulated based on the confirmation of development period and tectonic setting about lower order faults. According to the failure criterion of rock, the favorable development regions of the lower order faults are analyzed through the minor principal stress, the favorable directions are discussed by the plane shear stress, and the tendencies are analyzed by the vertical shear stress. The activity of the third faults in M Area of Nanpu Sag presents obvious segment and generation: The middle part of the above studied region is the main region of the lower order faults owing to the coefficient of the regional NS extension and the regional camber stress by paroxysmal eruption, the east part develops a set of nearly NE-trending lower fault, the west part develops a set of nearly NW-trending fault, and the apparent dip mainly presents north tendency.