渤海湾盆地渤中凹陷油藏断裂特征及对成藏的控制作用

发布时间：2018-11-20 06:16

【摘要】：渤中凹陷是环渤海湾盆地的沉积沉降中心,也是环渤海湾盆地重要的富油气凹陷之一。目前在凹陷周边所发现的油藏绝大部分是受断裂控制的构造或构造-岩性油气藏,这些断裂对油气藏的控制方式和影响程度,直接决定构造圈闭的评价结果和勘探部署方案。对渤中凹陷目前已发现的237个中浅层油气藏构造特征进行精细解剖,统计对比了断裂的级别、成因类型、断距、断层活动性、断层产状、组合样式、平面形态、遮挡类型、断层泥比率等指标与相应的油藏发育程度,发现在主断裂与次级断裂的合理配置的前提下,渤中凹陷中浅层有利于成藏的断裂特征为:走向NNE、近EW和NE,倾角66°~80°,断距20~150 m,断层活动速率在10~30 m/Ma,断层泥比率SGR大于0.3,断裂带泥质含量R_m大于0.35,组合样式为斜交式、雁列式、Y字形、似花状和阶梯状,并且断裂以反向遮挡为主。平面上在断裂相交处、凸形增压段更有利于油气聚集成藏。本质上说,断层封闭性是控制构造圈闭成藏的关键,断裂活动速率、规模和断裂类型是影响封闭性的根源。
[Abstract]:Bozhong sag is the sedimentary subsidence center of the Bohai Bay basin and one of the important oil-gas sag around the Bohai Bay basin. At present, most of the reservoirs found around the sag are structural or structure-lithologic reservoirs controlled by faults. The control mode and influence degree of these faults directly determine the evaluation results and exploration plans of structural traps. The structural characteristics of 237 middle and shallow reservoirs in Bozhong sag have been carefully dissected, and the grades of faults, genetic types, fault spacing, fault activity, fault occurrence, combination style, plane shape, occlusion type have been statistically compared. Based on fault gouge ratio and corresponding reservoir development degree, it is found that on the premise of reasonable allocation of main fault and secondary fault, the fault characteristics favorable to reservoir formation in Bozhong sag are as follows: strike NNE, near EW and NE, dip angle 66 掳~ 80 掳, fault distance 20 ~ 150 m. The fault activity rate is 10 ~ 30 m / Ma, the fault gouge ratio SGR is greater than 0.3, and the fault zone mud content R _ m is greater than 0.35. The combination style is oblique, geese, Y-shaped, flower-like and ladder-like, and the fault is mainly covered by reverse occlusion. At the intersection of faults, the convex pressurized section is more favorable for oil and gas accumulation and reservoir formation. Essentially, fault sealing is the key to controlling the formation of structural traps, and the fault activity rate, scale and type of fault are the root causes of the sealing.
【作者单位】：中国石油大学(华东)地球科学与技术学院;中国石油大庆油田采油八厂;中海石油(中国)有限公司天津分公司;
【基金】：国家科技重大专项(2008ZX05023-001-004-002;2011ZX05023-001-013)
【分类号】：P618.13

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