基于地震波形指示反演的砂砾岩储层预测——以中拐—玛南地区上乌尔禾组为例

Prediction of glutenite reservoir based on seismic waveform indicative inversion:a case study of Upper Urho Formation in Zhongguai-Manan area

准噶尔盆地中拐—玛南地区上乌尔禾组为扇三角洲前缘亚相沉积的砂砾岩,具有厚度大、横向变化快、岩石结构成熟度和成分成熟度均低的特点。砂砾岩储层的关键控制因素为泥质含量,根据泥质含量对上乌尔禾组砂砾岩进行划分,可以分为含泥砂砾岩和富泥砂砾岩。利用单一的测井曲线难以有效识别研究区的泥质含量,根据常规测井曲线的响应特征,利用中子测井曲线和声波时差测井曲线的幅度差来拟合砂砾岩储层泥质含量曲线,再经地震波形指示反演来预测砂砾岩优质储层的平面展布,实现了砂砾岩储层的定量化预测。经过钻井证实,这一方法预测结果符合率较高,油气显示良好,展示了本区良好的勘探前景。

The Upper Urho Formation in Zhongguai-Manan area of Junggar Basin mainly develops sandy conglomerate of fan delta front subfacies,with the characteristics of large thickness,rapid lateral variation,low maturity of rock structure and composition. The key controlling factor of glutenite reservoir in the study area is argillaceous content. According to the argillaceous content,the glutenite of Upper Urho Formation can be divided into argillaceous-bearing glutenite and argillaceous rich glutenite. It is difficult to identify the argillaceous content effectively in the normal log curve. According to the response characteristics of conventional log curve,the amplitude difference between CNL log curve and the AC log curve was used to construct the argillaceous content curve of the glutenite reservoir. The plane distribution of high-quality glutenite reservoir was predicted by seismic waveform indicative inversion,realizing the quantitative prediction of glutenite reservoir. The drilling proves that the prediction result accords with high rate and good oil and gas display,showing a good exploration prospect in this area.