普光地区上三叠统小塘子组泥岩分布地震预测

Prediction of mudstone distribution on top of middle Triassic Xiaotangzi formation in Puguang area

普光地区多井在雷口坡顶部气测显示较好,化验分析表明其上覆地层小塘子组发育优质烃源岩,因此,小塘子组作为重要的烃源层和盖层,其泥岩分布预测对普光地区雷口坡组顶部风化壳储层具有重要的意义。在明确小塘子组泥岩的岩石物理特征及测井响应特征的基础上,首先利用已钻井及三维地震资料,对泥岩进行精细井震标定、地质建模与正演模拟,明确小塘子组泥岩的地震反射特征;最终结合古地貌分析、属性分析等手段,确定泥岩发育的有利相带,并以此为基础,应用稀疏脉冲反演对泥岩厚度进行了定量预测,建立了一套适应于普光地区小塘子组泥岩的地震预测方法,预测了普光地区上三叠统小塘子组泥岩的分布,通过与已完钻井泥岩厚度的对比,证实了预测结果的可靠性。

Gas logging of multiple wells at the top of Leikoupo formation in Puguang area is better.The laboratory analysis shows that high quality source rocks are developed in Xiaotangzi formation of the overlying strata.Therefore,as an important hydrocarbon source layer and caprock,the mudstone distribution prediction of Xiaotangzi formation is of great significance to the top weathered crust reservoir of Leikoupo formation in Puguang area.On the basis of defining the petrophysical characteristics and logging response characteristics of mudstone in Xiaotangzi formation,the fine well-seismic calibration,geological modeling and forward mod?eling of mudstone were carried out by using the drilling and 3D seismic data,and the seismic reflection characteristics of mudstone in Xiaotangzi formation were clarified.Finally,combined with paleogeomorphology analysis,attribute analysis and other means,the favorable facies belt of mudstone development was determined.On this basis,the thickness of mudstone was quantitatively predicted by sparse pulse inversion,a set of seismic prediction method suitable for mudstone of Xiaotangzi formation in Puguang area was established,and the distribution of Upper Triassic was predicted.Then the comparison of mudstone thickness with that of completed drilling confirmed the reliability of the prediction results.