潍北凹陷构造演化对沉积成藏的控制作用

潍北凹陷构造演化过程复杂造成对沉积成藏规律认识不清，综合运用钻井、测井及地震资料，对潍北凹陷边 界断裂特征及沉积演化进行了深入分析，研究表明，受控于郯庐断裂带的持续活动，潍北凹陷经历了左旋走滑、左右旋 转换、右旋走滑和区域拗陷4 个构造演化阶段。左旋走滑期（Ek3）拉张控制形成了火成岩基底，奠定了潍北凹陷北断 南超构造格局；左右旋转换期（Ek2）发育了盆地烃源岩和东西方向的扇三角洲；右旋期（Ek1 Ed）形成了盆地最主要的 储盖组合。走滑形成的古凸起地形控制凹陷边缘扇体发育，自下而上沉积中心较沉降中心明显向东迁移。灶户断鼻带 是油气运移、聚集的主要指向区，沙四末期构造抬升运动形成了现今“东富西贫”的油气分布格局。东西部成藏模式存 在差异，东部地区为“单期成藏双向输导侧向运移”，西部地区为“两期成藏近源聚集”。

Controlling Effect of Tectonic Evolution on Deposition and Hydrocarbon#br# Accumulation in Weibei Sag

The complexity of tectonic evolution in Weibei Sag results in unclear understanding of its deposition and hydrocarbon accumulation law. Based on comprehensive analysis of well drilling，logging and seismic data，we analyzed the boundary fracture characteristics and sedimentary evolution in Weibei Sag. Studies show that due to the Tan-Lu fault zone continuing activities，Weibei Sag experienced four evolutionary stages：Sinistral strike-slip，Sinistral-Dextral conversion，Dextral strikeslip and regional depression. The sinistral strike-slipping（Ek3）formed igneous basement，established the tectonic pattern of Weibei Sag by sinking in the north and overlapping in the south. The basin hydrocarbon source rocks and fan-delta came from E W fan delta in sinistral-dextral conversion period（Ek2）. The main reservoir-cap combination formed in dextral strike-slip period（Ek1 Ed）. The convex′s ancient landforms characteristic formed from it controlled the hollows filling and the growth characteristic of fan-bodies；deposition center from bottom to top evidently migrated eastward compared to subsidence center. The Zaohu broken nose band is the main oil and gas migration and accumulation area. Tectonic uplift movement in Es4 last stage led to rich oil and gas distributed in east and poor distribution in west. Accumulation mode is different between east and west. Reservoir model of eastern region is single hydrocarbon accumulation period，bilateral transporting and lateral migration. Reservoir model of western region is two hydrocarbon accumulation periods and near source gathering.