西湖凹陷WBT地区平湖组下段有利储层预测

西湖凹陷WBT地区平湖组下段是该区主要的勘探目的层。通过对其岩石学、储集空间及物性特征进行分析，总结了研究区有利储层控制因素。在此基础上，利用沉积相、成岩相及异常压力分布图的叠合，对研究区有利储层分布范围进行了刻画。研究表明，WBT地区平下段储层主要为长石岩屑砂岩，储集空间主要为次生溶孔，但仍保留大量原生孔隙。沉积相控制了储层的展布特征，成岩作用对原生孔隙影响较大，但异常高压对原生孔隙具有保护性作用。预测WB断层下降盘、BT断层下降盘及WB地区高带为Ⅰ、Ⅱ类有利储层区。

Favorable Reservoir Prediction of the Lower Pinghu Formation in WBT Area of Xihu Sag

As the main exploration target in WBT Area of Xihu Sag,the Lower Pinghu Formaiton was investigated.By analyzing the characteristics of lithology,reservoir space and physical property,the favorable controlling factors of reservoir quality were summarized.On this basis,the maps of sedimentary facies,diagenetic facies and pressure coefficient distribution were overlapped to fix the distribution area for favorable reservoirs.And the result shows that lithology of the Lower Pinghu Formation is mainly feldspar lithic sandstone.The reservoir space is mainly secondary dissolution pores,but a large number of primary pores are still retained.The distribution characteristic of the reservoir is controlled by sedimentary facies and diagenesis has a great effect on primary pores,which is also protected by the abnormal high pressure.It is predicted that the down thrown block of WB Fault and BT Fault and the western WB Area are I and II favorable reservoir regions.