缅甸Shwebo盆地油气地质特征及勘探潜力

Petroleum Geology and Exploration Potential of Shwebo Basin,Myanmar

Shwebo盆地是在中生代边缘海沉积盆地基础上演化而成的新生代弧后盆地,经历了边缘海盆地—弧后盆地2个主要演化阶段。盆地的主要烃源岩和储盖组合均发育于新生代弧后阶段。始新统烃源岩的排烃高峰期是渐新世—中新世,以生气为主。始新统自生自储组合和渐新统下生上储组合是该盆地最重要的成藏组合方式。盆地西部岛弧断裂带发育一系列的断背斜圈闭,盆地东部发育一系列的正花状构造和断背斜圈闭,沿着Sagaing走滑断层呈带状分布。Shwebo盆地中西部的Shwebo-1号构造和东部的斜坡区礁构造为最具潜力的勘探区域。

Shwebo Basin is the back-arc basin developed and formed on the basis of Paleozoic marginal sea basin.The tectonic evolution of Shwebo Basin can be described in terms of an early stage of marginal sea basin and a later stage of back-arc basin.The primary source rocks,reservoirs and seals had formed in the second stage.Eocene source rocks generated a mass of hydrocarbon characterized mainly by gas from Oligocene to Miocene.The assemblage of self-generated and self-preserved reservoir was the most important type in the Eocene Formation,and the Oligocene reservoir can also accumulated hydrocarbon from the Eocene source through faults.There are thrust faulted traps in western basin and flower structure traps and fault anticline traps along the Sagaing strike fault in eastern basin.There are two potential exploration targets,Shwebo-1faulted anticline traps in the Eocene and Oligocene formation in western basin,and Reef anticline traps in the Eocene and Oligocene formation in eastern basin.