子洲气田天然气储层的AVO研究

Research of AVO Technique in Gas Reservoirsof Zizhou Gas Field

AVO分析方法是利用地震反射波振幅与炮检距的关系（Amplitude versus Offset简称AVO）来识别岩性检测油气的一种地震技术。与榆林气田相似，在子洲气田勘探中，运用该技术见到很好效果。子洲气田上古生界二叠系山西组合气砂岩主要属三角洲平原及三角洲前缘分流河道沉积。由于含气砂岩和致密砂岩在波阻抗上差异较小．在常规的岩性反演剖面上，很难区分含气砂岩和致密砂岩。引入AVO处理分析方法，利用不同岩性泊松比差异所形成的AVO特征响应．可以有效区分地震高阻抗层的岩性及含气性，从而减少了地震岩性解释上的陷阱。在开发中。应用高保真的CMP道集资料进行AVO处理分析，是提高天然气开发井预测成功率的一种有效手段。

Similar to that to Yulin gas field, application of Amplitude-versus-OffSet （AVO） analysis technique to Zizhou gas field exploration brings good results. It is hard to distinguish gas-bearing sandstone from tight sandstone in conventional lithologic inversion profiles, due to minor differences of wave impedance between gas-bearing and tight sandstone. By introduction of the AVO analysis technique we can effectively distinguish the lithology and gas-bearing from tight sandstone with high impedance, by using the AVO character responses to various lithology poisson＇s ratio differences. Thus the errors in seismic lithology interpretation can be minimized. During the exploitation of gas field, AVO treatment analysis by application of high fidelity data of CMP gather is an effective way to enhance the success ratio of development well of gas prediction.