板桥凹陷断裂陡坡带沙一段层序样式和沉积体系特征及其成藏模式研究

Sequence Patterns,Characteristics of Depositional Systems and Model of Reservoirs of Fault Steep Slope Belt of the First Member of Shahejie Formation in Banqiao Sag

板桥凹陷为一单断式箕状断陷,在凹陷的西北侧断裂陡坡带发育,本文以该区断裂陡坡带沙河街组一段为研究对象,对其层序样式和沉积体系特征进行了深入研究。研究发现:在断裂陡坡带以下高位扇三角洲前缘没有低位扇三角洲前缘发育的规模大,且低位时期下切谷和河流沉积较发育;陡坡带控制着砂体空间展布特征,砂体顺着断裂带分布,与断裂带的走向平行;断裂陡坡带还控制着优质烃源岩的发育部位,砂体、优质烃源岩和控盆断层组合,形成了多种油藏样式。本文总结了该区断裂陡坡带层序样式和沉积体系特征,建立了相应的油藏模式。

Banqiao Sag is the half-graben rift sag. The steep slop belt developed in the north-west side of Banqiao Sag. The article analyzed the sequence patterns and the characteristics of the first-member of Shahejie Formation in the area of the fault steep slope belt. The scale of the highstand delta front is smaller than the lowstand delta front, but the incise valley and the river deposition developed in the time of the lowstand. The steep slop belt controlled the distribution of the sand bodies, which developed along the direction of the fault and paralleled the steep belt. The steep slop belt also controlled the growth of the good source rocks. So the sand bodies, the good source rocks and the controlling faults together controlled the development and distribution of reservoirs. According to the results, the article sum up the sequence patterns and the characteristics of depositional systems, at last built the model of the reservoirs in the fault steep slope belt.