Kura盆地区域盖层与成藏模式

盆地性超压油藏的形成,必须受控于盆地特殊的地质背景。阿塞拜疆境内的Kura盆地,位于里海西缘,是夹持于大、小高加索山脉之间的山间裂谷盆地。在古特提斯海的封闭过程中,土耳其板块俯冲至西徐亚板块之下,在地表形成拉张裂陷的地质背景。盆地发育中表现出大套的泥岩沉积,虽然区域储层顶部出现过两次沉积间断,但间断时间均较短,未造成油藏泄压,加之再次下沉的深度未超过储层的原沉积深度,最终形成盆地性的超压油藏。

PATTERN OF THE RESERVOIR FORMATION AND TERRTRIAL CAPROCK IN KURA BASIN

The formation of overpress the reservoir as whole basin is determined by special geology background of basin.The Kura basin in Azerbaijan is located in the west of Caspian,and is clamped between rift valley basins of big and small Caucasia.The tension background had formed while Turkey plate dives down under Xixueya plate as Tethys closes.The basin subsided and massive sediments of thick mudstone developed.There were twice short-term hiatus in the upper of regional reservoir,and the pressure of reservoir did not release.Furthermore,the later subsided depth was less than that of original formation,so the overpressure are reservoirs could be formed.