【摘要】 鄂尔多斯盆地大牛地气田二叠系下石盒子组致密砂岩储层孔隙度低,含气饱和度变化所产生的地球物理特征变化相对微弱,储层流体识别困难。为此,基于岩石物理参数测试,优选出对含气性敏感的弹性参数组合;利用岩石物理参数关系,推导出基于地震纵、横波阻抗的流体敏感弹性参数计算公式,构建了一个新的含气性识别因子。利用叠前地震资料纵、横波阻抗同步反演结果计算出新的含气性识别因子数据体,对大牛地气田进行了流体识别。研究结果表明,新的含气性识别因子能有效地突出研究区流体变化的影响,对致密砂岩储层的含气性识别能力较强,且具有很好的抗噪能力。更多还原

【Abstract】 The tight sandstone reservoirs in lower Shihezi formation from Daniudi Gasfield of Ordos Basin is characterized by low-porosity,and the variation of geophysical characteristics followed by oil saturation and gas saturation is weak relatively,therefore the identification of reservoir fluid is difficult in the area.In order to solve the problem,we optimized gas-bearing sensitive elastic parameters based on rock physical parameters testing.By using the relationship in parameters,we derived computation formula for fluid sensitive elastic parameters and constructed a new gas-bearing identification factor.By utilizing the P-wave and S-wave impedance simultaneous inversion result of prestack seismic data,the data volume of new gas-bearing identification factor was computed and applied to the reservoir fluid detection in Daniudi Gasfield.The application results indicate that the new gas-bearing identification factor can effectively highlight the impact of fluid changes and is sensitive to the gas-bearing tight sandstone reservoirs with good anti-noise capability.更多还原