【摘要】 利用叠后地震反演进行油气检测存在一定的局限性,因此提出了利用叠前地震反演预测民丰地区沙四段盐下砂砾岩体的含油气性。首先,通过岩石地球物理特征分析,求取目的层段的密度、纵波速度、横波速度和泊松比等参数;然后,通过正演模拟分析气层在叠前地震道集上的响应特征;最终,根据交会分析技术,对比了截距—梯度、速度—密度、拉梅常数—剪切模量和速度—泊松比等参数对油气检测的适用性,优选对研究区储层含油气性比较敏感的拉梅常数和泊松比作为反演参数。通过叠前地震反演,分析了敏感参数对气层的判识程度。应用结果表明,通过对叠前地震反演提取的拉梅常数和剪切模量2组参数进行交会解释,气层反射特征与丰深1井砂砾岩体实钻结果吻合较好,预测有利含气面积为109km2,天然气资源量为290×108m3。更多还原

【Abstract】 In view of some restrictions of application of pre-stack seismic inversion to hydrocarbon detection, application of prestack seismic inversion to predicting hydrocarbon for conglomerate body in Minfeng area is suggested. Firstly, the parameters of interest interval including density, compressional wave velocity, shear wave velocity and Poisson’ s ratio are calculated by means of analyzing geophysical signature. Secondly, the seismic response characteristics for gas bearing reservoir in pre-stack gather are analyzed by forward modeling. Lastly, based on intersection analysis methods, the applicability of parameters such as intercept-gradient, velocity-density,Lambda constant, velocity-Poisson’ s ratio to hydrocarbon detection is correlated and Lame’ s constant and Poisson’ s ratio which are sensitive to hydrocarbon in interval of interest are selected as inversion parameters. The ability of sensitive parameters to locate the gas bearing reservoir is analyzed through prestack seismic inversion. The application results indicate that the research results acquired by intersection interpretation of lambda constant and shear modulus extracted from pre-stack seismic inversion coincides with drilling test results, and predicted favorable gas-bearing area of 109 km~2, natural gas resource of 290x10~8m~3.更多还原