济阳坳陷孤岛碳酸盐岩潜山构造演化及油气成藏特征

济阳坳陷孤岛潜山最早形成于中生代.在新生代拉张环境下,由于孤西、孤南和孤北断层的夹持,孤岛潜山持续凸起,至馆陶组沉积期才被地层全面披覆形成潜山披覆构造.孤岛潜山下古生界经历了多期构造运动,长期处于隆起状态,受风化侵蚀和大气淋滤作用的影响,岩溶作用广泛发育,形成了奥陶系八陡山组或上马家沟组碳酸盐岩风化壳储层和多套下古生界碳酸盐岩内幕储层.孤岛潜山处在渤南、孤北和孤南洼陷之间,长期为油气的指向区,孤西断层、孤南断层、孤北断层、不整合面及裂缝系统为油气运移提供了有利的疏导体系.但潜山顶部存在一个"天窗",使得油气不能大规模聚集.

A study on the structural evolution and the petroleum characteristics of Gudao carbonate buried hill in Jiyang depression, China

The Gudao buried hill originally formed in Mesozoic.Under the circumstance of the Neozoic pull-apart stress field,being controlled by Guxi,Gunan and Gubei faults,the Gudao buried hill swelled continuously.It was not until the Guantao Formation deposited that the Gudao buried hill was overall covered by strata to form the buried draping structure.The Lower Paleozoic of the Gudao buried hill has suffered multi-period tectonizations and has been the eminence for quite a long time.Because of the influence of weathering corrosion and atmosphere leaching in the area,the karstification has developed widely.As a result,the carbonate weathering crust reservoirs,such as the Badou or Shangmajiagou Formations of Ordovician and a series of carbonate inner-episode reservoirs in Lower Paleozoic have formed in the area.The Gudao buried hill sets among Bonan,Gubei and Gunan sags has been a good area for the oil and gas's migration and gathering.Meanwhile,the Guxi,Gunan,Gubei faults,the plane of unconformity and crack system have provided an available migration system for oil and gas.However,the "clearstory" setting on the top of the buried hill makes the gathering of oil and gas in large scale impossible.