【摘要】 鄂尔多斯盆地大牛地气田二叠系下石盒子组一段(盒一段)属于典型的辫状河道沉积,砂岩较厚,气层分布存在着较强的非均质性,气藏的水平井开发难度较大。为了提高致密砂岩气藏储层"甜点"钻遇成功率,在高分辨率层序地层和沉积体系分析的基础上,明确了盒一段辫状河道沉积相展布规律及沉积特征,提出了综合应用三维地震资料解释、地震波形分析、AVO含气检测及地质统计学反演等地震预测成果设计水平井轨迹的技术方法。其中,AVO负梯度异常和地质统计学反演等地球物理预测技术发挥了特别重要的作用,为大牛地致密砂岩气藏水平井开发提供了技术支持。层序地层理论和有效的地球物理预测方法结合是提高致密砂岩气藏储层"甜点"钻遇成功率的理想途径。更多还原

【Abstract】 The 1st member of Permian Xiashihezi Formation(He-1) in Daniudi gas field,Ordos Basin,is braided channel deposits with large thickness.As heterogeneity of the gas layer distribution is strong,development of the gas reservoirs with horizontal wells is difficult.In order to increase the success rate of drilling"sweet spot"in this tight sandstone layer,we studied in detail the sedimentary facies and characteristics of the braided channel deposits in He-1 based on analyses of high resolution sequence stratigraphy and sedimentary system,and presented methods to integrate various seismic data into design of horizontal well trajectory,such as 3D seismic interpretation,waveform analysis,AVO gas detection and geo-statistical inversion.Among these seismic data,negative AVO gradient and geo-statistics inversion are the most important and can provide strong technical support to the development of the tight sand gas reservoirs with horizontal wells in Dajiudi gas field.The integration of sequence stratigraphy theory with geophysical prediction methods is an effective way to improve the success rate of "sweet spot"drilling in tight gas sandstone reservoirs.更多还原