渤海湾地区不同方向断裂带的封闭性

构造应力场的最大主压应力方向与同时期活动断裂走向的相互关系决定着断裂的封闭程度 ,两者的锐夹角越大 ,断裂的封闭性越好 ;两者的锐夹角越小 ,断裂的封闭性越差 ,渗透性越好 ,有利于流体的运移。据此用线性代数法换算出的断裂闭合系数可半定量地评价断裂的封闭条件 ;再结合不同油气主运移期的封闭性变化的历史 ,可对断裂带的有利的油气聚集部位进行预测。通过对渤海湾地区的油气聚集进行综合评价 ,认识到东西向和南北向展布的断陷带对油气的聚集最为有利 ,北西向展布的和现今断裂活动性较弱的北东向展布的断陷带中的部分地段也很有前景。预测庙西 1号、垦利 3号、庙西 3号等断裂带为下一步有利的油气勘探构造带。

SEALING PROPERTIES OF DIFFERENT DIRECTION FAULTS IN THE BOHAI BAY AREA

The sealing property of faults is affected by the combining manner between the maximum principal compressive stress orientation of tectonic stress field and the strike direction of faults at the same stage. When the acute angles of them are larger, the sealing properties of faults are better. If the acute angles of them are smaller, the sealing properties of faults are poorer, the liquid permeability in fault is better and good for the liquid migration. For the reasons given above, we can appraise the sealing property of fault semi-quantitatively used the sealing coefficient calculated by the method of linear algebra. By analyzing the evolving history of the sealing property of faults in the different stages of petroleum migration, the advantaged parts, which can gather oil and gas, are forecasted in some fault zones. By evaluating to the Bohai Bay area synthetically, it is recognized that the petroleum gathering of fault depressions at east-west or north-south trending are the best, and the part areas of the northeastward or northwestward of fault depressions, sometimes are well for petroleum enrichment. Miaoxi-1 fault, Kenli-3 fault and Miaoxi-3 fault are forecasted for beneficial fault depression zones of petroleum exploration in the future.