古龙-徐家围子地区营城组古构造应力场数值模拟—构造裂缝发育区带预测及对比研究

裂缝性油气藏是大庆油田古龙-徐家围子地区主要的油气藏类型之一,营城组是该区深层找气的主要目的层。影响本区营城组构造变形的构造事件确定在晚白垩世早期的青山口组一段沉积后。用石英晶格位错密度法测试得到了该期的构造差应力值,采用弹-塑性增量法对该期构造应力场进行数值模拟表明,该区晚白垩世早期最大主应力方向为北北东-南南西向,构造应力值在平面上整体呈近南北向带状分布。预测古龙-徐家围子地区营城组构造裂缝发育区带位于古龙地区西部及徐家围子地区的西部和北部,为有利的油气聚集区。

Numerical simulation of palaeotectonic stress field of Yingcheng Fm in Gulong- Xujiaweizi area: prediction and comparative study of tectoclase development area

Fractured reservoir is one of the main oil and gas reservoirs in Gulong - Xujiaweizi area of Daqing oilfield, and Yingcheng Fm is the main deep gas target in this area. The tectonic event that has influenced the tectonization of Yingcheng Fm in this area is believed to have occurred after the deposition of the 1st member of Qingshankou Fm during early Late Cretaceous. The tectonic differential stress value at this stage has been measured by using the quartz dislocation density method, and the tectonic stress field at this stage in the study area has been numerically simulated by using the elastic-plastic incremental method. The simulation shows that the maximum principal stress in the area was in NNE - SSW direction in early Late Cretaceous, and the tectonic stress values was characterized, as a whole, by nearly meridional and zonal distribution. The tectoclase development zones of Yingcheng Fm in Gulong - Xujiaweizi area are predicted to be located in the western part of Gulong area and the western and northern parts of Xujiaweizi area, and they would be the favorable oil and gas accumulation areas.