Abstract: The core observation,thin-section analysis and oil well testing were used to research the types and origins of sand dikes in the Paleogene soft-sediments of Jiyang Depression.The result shows that there are four kinds of sand dikes including throat-like sand dikes,venation-like sand dikes,zonary sand dikes and crack-filling sand dikes.The sand dikes in Jiyang Depression are mainly related to the ancient earthquake.The shaking-fluidization may be the main mechanism to form throat-like sand dikes.The venation-like sand dikes and zonary sand dikes may be related to the shaking-liquefaction-pushing.The crack-filling sand dikes are generated under the shaking-pulling crack-filling actions.The research on sand dikes is favorable for exploration of hydrocarbon reservoirs and for deducing ancient deposition setting and ancient earthquake grade.

Key words: Jiyang Depression, Paleogene, sand dikes, generation mechanism, hydrocarbon accumulation, ancient deposition setting

摘要： 利用钻井岩心观察、岩石薄片鉴定、油气井测试等手段,对渤海湾盆地济阳坳陷古近系砂岩脉的类型、成因的研究结果表明,济阳坳陷古近系软沉积变形层中的砂岩脉形态复杂,类型多样。根据其形态特征与赋存条件,可分为喉道状砂岩脉、脉络状砂岩脉、飘带状砂岩脉和裂缝充注型砂岩脉4种主要类型。震动流体化作用是形成喉道状砂岩脉的主要成因机制,脉络状砂岩脉和飘带状砂岩脉与震动液化挤压作用有关,裂缝充注型砂岩脉则主要形成于震动拉张裂缝充填作用。对砂岩脉的研究有助于寻找有工业价值的油气藏以及推断古沉积背景和古地震的震级。

关键词: 济阳坳陷, 古近系, 砂岩脉, 成因机制, 油气聚集, 古沉积背景