济阳坳陷孤西潜山分布特征及其控因

Distribution Characteristics and Controlling Factors of Guxi Buried Hill in Jiyang Depression

摘要: 多期构造运动作用的叠加造成孤西潜山地质条件非常复杂，制约了研究区油气勘探进程。为指导下一步油气勘探，利用丰富的钻井、地震资料，对潜山分布特征及其控因进行了研究。结果表明，孤西潜山带由高潜山与低潜山2类潜山组成，其中高潜山埋藏相对较浅，上覆地层主要是新近系，低潜山埋藏深度一般在3500 m以上，上覆地层为古近系。各潜山高点均分布在南西部位，古生界残留地层主要分布在NW向断层下盘，中生界主要分布在NW向断层上盘。印支运动时期，逆断层上盘古生界剥蚀强烈，下盘古生界保留相对完整，燕山运动早中时期，逆断层回返控制了中生界沉积，厚度中心位于断层下降盘，燕山运动晚期研究区整体隆升，中生界遭受剥蚀，喜山运动时期形成的近EW向、NNE向断层控制了潜山差异沉降，断层上盘下降深埋而形成低潜山，断层下盘相对隆升，中古生界继续遭受剥蚀形成高潜山。

Abstract: The geological conditions of Guxi buried hill are very complicated due to the superimposition of multi-stage tectonic movements, which restricts the exploration process of oil and gas in the study area. In order to guide the next oil and gas exploration, the distribution characteristics and controlling factors of the buried hill are studied by using abundant drilling and seismic data. The results show that the Guxi buried hill is composed of high buried hill and low buried hill. The high buried hills are relatively shallow, and the overlying strata are mainly Neogene. The buried depth of the low buried hills is generally over 3,500 m, the overlying strata are Paleogene. The high points of all buried hills are distributed in the south-west, and the Paleozoic residual strata are mainly distributed in the foot-wall of the NW-trending fault, while the Mesozoic strata are mainly distributed in the hanging-wall of the NW-trending fault. During the Indosinian movement, the Paleozoic strata were strongly eroded in the upper plate of the reverse fault, and the Paleozoic strata in the lower plate were preserved relatively intact. During the early and middle period of the Yan-Mountains movement, the reverse fault returned and controlled the Mesozoic sediments, the study area was uplifted and the Mesozoic was denuded in the later Yan-Mountains movement. Near EW-trending and NNE-trending faults formed during the Himalayan movement, which controlled the differential subsidence of the buried hill. The hanging-wall of the fault dropped and buried deeply to form low buried hill. The foot-wall of the fault rose relatively, and the Mesozoic and the Paleozoic strata continued to be eroded to form high buried hill.