东营凹陷西部沙四上亚段超压成因及增压模式

滩坝砂岩是东营凹陷西部沙四上亚段的重要沉积储层,超压对滩坝砂岩油气成藏具有明显的控制作用。利用测井参数对超压的响应特征建立了超压成因的判别方法并对超压成因进行了分析,认为东营凹陷沙四上亚段深湖相沉积物的快速沉积埋藏使得欠压实成为超压形成重要因素;沙四上亚段优质烃源岩的广泛发育及热演化使得生烃增压成为超压形成的另一个重要原因。建立了东营凹陷西部增压模式,将超压的演化分为正常压实阶段、欠压实及早期生烃增压阶段以及大量生、排烃增压三个阶段,在超压发育的不同阶段,欠压实与生烃增压先后成为最重要的因素。

Origin of overpressure and booster mode of upper Es4 formation of western Dongying depression

Beach bar sandstones are important sedimentary reservoirs in upper Es4 formation of western Dongying depression and overpressure has significant controlling effect on hydrocarbon accumulation of beach bar sandstones.By using response characteristics of logging parameters on overpressure,a discrimination method of overpressure causes has been established.Through overpressure causes analysis,it believed that rapid sedimentary burial of sand in Dongying depression is one of the important factors of overpressure.The extensive development and the thermal evolution of the four sub-segment sand source rocks makes hydrocarbonbooster become another important reason for the formation of overpressure.The booster mode of western Dongying depression has been established and the overpressure evolution can be divided into three stages,namely normal compaction stage,early under-compaction hydrocarbon booster stage,and a lot of hydrocarbon generation and expulsion supercharged stage.At different stages in the overpressure development,under-compaction and hydrocarbon booster have become the most important factors.