鄂尔多斯盆地桥沟湾地区上三叠统延长组层序格架内储层发育规律

 应用高分辨率层序地层学理论、测井小波分析及频谱分析方法，对延长组层序地层单元进行定量识别，共识别出5个长期、21~25个中期基准面旋回层序。通过层序格架内储层发育规律分析，认为可容空间与沉积物供应量的比值（A/S）及层序界面对储层的空间展布和物性变化具有明显的控制作用，最有利的储层发育位置出现在长期基准面上升早期和下降晚期，特别是中期和长期两个级次基准面相互重叠的界面两侧，酸性孔隙流体沿着界面运移，有利于形成次生孔隙，对改善储集层储集性能有利。与传统层序地层方法相比，该方法能消除人工划分层序的不确定因素，提高旋回划分、对比的精度和准确性，提高油气勘探成功率。

Distribution of Reservoirs in Sequence Stratigraphic at the Upper Triassic Yanchang Formation at Qiaogouwan Area in Erdos

The high-resolution sequence stratigraphic theories, and the methods of wavelet analysis and frequency spectral analysis were used to define the sequence stratigraphic framework of the Upper Triassic Yanchang Formation, which have five long base-level cycles and 21 to 25 middle base-level cycles. Based on studying the relationship between the sequence stratigraphic chronostratigraphic framework and reservoir development, it is found that the development and distribution of reservoir has been apparently controlled by the A/S and boundary of sequence stratigraphy of Yanchang Formation. Sandstone reservoirs with relatively good properties occurred mainly at the early stage of the ascending long base-level cycle and the late stage of the descending middle base-level cycle, especially at both sides of the interface of long-term base level cycle and middle-term level cycles. Sour fluids migrate along the interface, favoring the formation of induced porosity, which can improve the reservoir. Compared with traditional method, this method can eliminate the uncertainty of artificial division of sequence, improve precision and accuracy of cycle division and correlation, and improve the success rate of oil and gas exploration.