济阳坳陷埕岛地区潜山断裂的特征及封闭性研究

Study on characteristics and sealing of buried hill faults in Chengdao area,Jiyang Depression

断裂是埕岛地区潜山油气聚集成藏最主要的控制因素。利用高精度三维地震资料和钻井资料结合区域应力场分析,对潜山断裂体系进行系统的解剖;从局部应力场特征、断层性质、新生代活动强度和产状配置定性评价断层的封堵性,并形成基于断面两侧瞬时频率属性变化率的封闭性预测方法。研究结果表明,研究区主要发育NW向走滑伸展断层、NNE向左旋压扭断层和近EW向伸展断层,主要控山断裂将埕岛地区划分为西排山、中排山和东排山。成藏期不活动断裂封闭性好,新生代活动的断裂,增压段封闭性好,释压段及拉张断裂封闭性差。西排山断层封堵,油源风险大;中排山断层封堵性有一定风险;东排山整体封堵条件好,成藏条件有利。

Faults are the most important controlling factor for oil-gas accumulation of buried hills in the Chengdao area.Combined with the regional stress field,the buried hill fault systems were systematically analyzed by using high-precision 3D seismic data and drilling data.The sealability of the fault was qualitatively evaluated from the characteristics of local stress field,fault properties,Cenozoic activity intensity,and occurrence configuration,and then it was formed a sealability prediction method based on the instantaneous frequency attribute change rate on both sides of the section.The research results show that the study area mainly develops NW strike-slip extensional faults,NNE left-handed compression-torsion faults,and near-EW extensional faults.The main mountain controlling faults divide the Chengdao area into Xipai Mountain,Zhongpai Mountain,and Dongpai Mountain.The inactive faults during the accumulation period have good sealing properties,the active faults in the Cenozoic have good sealing properties in the pressurized section,and the pressure-releasing section and tensile fractures have poor sealing properties.The Xipai Mountain fault is blocked,and the oil source risk is high;the Zhongpai Mountain fault has a certain risk of plugging;the Dongpai Mountain fault has good overall sealing conditions and favorable accumulation conditions.