鄂尔多斯盆地东部晚侏罗世-早白垩世应力场
The Field Stress between Late Jurassic and Early Cretaceous in the Eastern Ordos Basin

鄂尔多斯盆地是近年研究的热点区域.以鄂尔多斯盆地东部上古生界在燕山运动主幕期间(晚侏罗世-早白垩世)的应力场量化研究为目标，以期为应力场数值模拟及储层裂缝预测提供边界条件.通过盆地边界同构造期构造形迹应力反演和地层剥蚀量恢复结果探讨了晚侏罗世-早白垩世三轴应力状态及水平最大主应力方向；基于泥岩压实曲线及Newberry力学模型计算了附加构造应力及垂直地应力，进而获得了研究区上古生界在晚侏罗世-早白垩世的三轴主应力大小及差应力值.研究结果显示，研究区在燕山运动主幕期间最大主应力近水平，方向为SEE98°，中间主应力近竖直，最小主应力为NWW方向；上古生界储层(平均恢复埋深为4 600 m)在燕山运动主幕的三轴主应力大小分别为93.2～101.3MPa、65.8～67. 2MPa、53.1～53.6MPa，差应力为40.1～48.0MPa.研究结果为区域构造应力场数值模拟、储层裂缝预测及裂缝型油气藏有利区优选等油气勘探工作提供了必要的基础.
The East Ordos basin is the hotpoint in recent years. In order to supply boundary conditions for field stress numerical simulation and fractures prediction in the eastern Ordos basin, this paper focus on the study of the specific parameters of the field stress between Late Jurassic and Early Cretaceous of Upper Paleozoic in eastern Ordos basin. Based on the retrieving of the syntectonicstructural deformation, calculatingof denudation thickness and the analyzing of the mudstone compaction curve, this paper got the triaxial stress state, the maximum horizontal principal stress direction, and the additive tectonic stress, the vertical earth stress, in situ stress and differential stress. The results show that, the maximum and minimum principal stress were nearly horizontalwith the direction of the former point to SEE98°. The intermediate principal stress was nearly vertical. The triaxial stresses and the differential stress, which were get from Upper Paleozoic, located in 93.2 to 101.3MPa, 65.8 to 67.2MPa, 53.1 to 53.6MPa and 40.1 to 48.0MPa respectively. Those results providesignificant basis for field stress numerical simulation, fractures prediction as well as the optimization of favorable exploration zones in the fracturedreservoir