叠前综合反演技术在西湖斜坡WYT地区储层预测中的应用  

Application of prestack comprehensive inversion technique to reservoir prediction in WYT area of West Lake Slope

作　　者：朱宝衡 ZHU Baoheng(Institute of Exploration and Development,SINOPEC Shanghai Offshore Oil&Gas Company,Shanghai 200120,China)

机构地区：[1]中国石化上海海海洋油气分公司勘探开发研究院,上海200120

出　　处：《复杂油气藏》2023年第4期387-392,共6页Complex Hydrocarbon Reservoirs

摘　　要：西湖凹陷平湖构造带武云亭(WYT)地区储层厚度薄,横向变化快,常规叠后和单一叠前储层预测方法在该地区存在一定的局限性。针对WYT地区储层开展叠前综合反演技术,首先利用岩性-物性量板,采用Ipsom智能判别器实现岩相自动识别;采用BP神经网络算法,利用密度、伽马、纵波速度、电阻率,进行横波速度预测,降低了横波速度预测的不确定性;通过岩石物理分析发现,WYT地区砂岩具有较低的纵横波速度比和泊松比特点。在上面研究的基础上开展武云亭(WYT)地区叠前地震随机反演。利用最终反演的弹性参数属性及岩性数据体,精细恢复和反演了WYT地区平湖组和宝石组的砂岩厚度,实现了单砂组级别的砂岩空间展布分析,为WYT地区分析有利砂体展布特征及下步井位提供依据。The reservoir thickness in the Wuyunting(WYT)area of the Pinghu structural belt in the Xihu Depressionand is thin,and the lateral change is fast.Hence,the conventional post-stacking and single pre-stacking reservoir prediction methods have specific limitations in this area.The prestack comprehensive inversion technique is developed for the reservoir in the WYT area.Firstly,the lithofacies automatic identification is realized using the lithologic-physical quantity plate and the Ipsom intelligent discriminator.The BP neural network algorithm is used to predict S-wave velocity using density,gamma,longitudinal wave velocity,and resistivity,reducing the uncertainty of transverse wave velocity prediction.It is found through the petrophysical analysis,that the sandstone in the WYT area has the characteristics of lower longitudinal and transverse wave velocity ratios and Poisson's ratios.Based on the above research,a random inversion of prestack earthquakes is carried out in the Wuyunting(WYT)area.Through the elastic parameter attributes and lithologic data of the final inversion,the thickness of sandstones in the Pinghu Formation and Baoshi Formation in the WYT area is finely restored and inverted.The spatial distribution analysis of sandstones at the level of single sand group is realized.It provides the basis for analyzing the favorable sandbody distribution characteristics and the following well location in the WYT area.

关 键 词：自动岩相识别 神经网络算法 叠前多参数反演 地震随机反演 

分 类 号：P631[天文地球—地质矿产勘探]