济阳坳陷东部垦东孤东潜山带走滑断层特征与成因分析

济阳坳陷东部垦东-孤东潜山带是胜利油田重要的油气产区,对该区带内走滑断层特征及形成机制的研究有助于分析走滑活动对油气聚集成藏的影响。为此,通过地震剖面精细解释和相干切片分析，综合研究了济阳坳陷东部走滑断层在剖面上与平面上的特征。结果表明,在剖面上发育明显的负花状构造,而在平面上则伴生一系列雁行断层,这些断层与走滑断层呈45°斜交,形成“入”字型形态。通过区域构造背景以及走滑成因分析，明确了该区走滑断层的形成机制：在始新世中期,由于太平洋板块向西斜向俯冲于欧亚板块之下,加上印度洋板块北东向的推挤,中国东部处于北东-南西向的挤压之下,受南部青坨子和陈家庄凸起的限制,垦东-孤东潜山带发生逆时针旋转,由于各潜山距离旋转中心的距离不同,相邻块体之间扭动程度存在差异,潜山带的分界断层分段扭动而发生相对滑移,最终演化成走滑断层。

The structural feature of the strike-slip faults in eastern Jiyang Depression as a key oil-gas production area is studied on structural feature and dynamic mechanism to analyze its impact on hydrocarbon accumulation.By seismic section interpretation and coherence slice analysis,the distribution feature of the strike-slip faults in eastern Jiyang Depression is studied.Negative flower structures are found around strike-slip faults on seismic profiles and a group of echelon faults develop beside the strike-slip faults on coherence slice.The echelon faults and strike-slip fault are oblique crossing with an angle of 45° with the shape of “λ” style.At the middle Eocene,the Pacific Plate westward subducted beneath Eurasia Plate and the India Plate northeastward extruded the Eurasia Plate.The eastern China was under the NE-SW compression.For the limit of block of the Qingtuozi uplift and Chenjiazhuang uplift located at the south of Kendong buried hill,the Kendong-Gudong buried hill structural belt is anticlockwise rotated around its southeast corner.For the different rotation radius,the turning extents of Kendong buried hill and Gudong buried hill are quite different.The boundary faults of buried hills arewrenched and finally became strike-slip faults.