火山岩AVO正演及应用

AVO FORWARD MODELING AND APPLICATION IN VOLCANIC ROCKS

岩石的孔隙度、流体饱和度等信息是影响AVO（地震波振幅随偏移距变化）的重要因素。根据松辽盆地北部某地区全波列测井数据，利用Gassmann方程对含气性地层进行了流体替换研究，分析了孔隙度及含气饱和度变化对地层AVO的影响，正演研究表明，纵横波速度比、泊松比是识别气藏的有效属性。AVO的响应表明，对松辽盆地北部某地区低孔隙度火山岩储层，孔隙度的变化对AVO的影响要大于流体的影响。AVO截距（P）和斜率（G）交会分析表明，P属性对含气饱和度变化要比G属性敏感。

Rock porosity and fluid saturation are key factors to AVO. Based some places in the northern part of Songliao basin, fluid substitution analysis on full wave train logging data from has been performed to gas-bearing strata using Gassmann Equation, in which effects of porosity and gas saturation variations on AVO have been analyzed. The result of forward modeling shows that P-wave velocity/S-wave velocity rate and Poisson ratio are effective attributes for gas pool identification. AVO response indicates that for the low-porosity volcanic reservoir in some places in northern Songliao basin, porosity variations are much more influential on AVO than fluid. AVO intercept （P） and gradient （G） crossplot analysis implies that P attribute is more sensitive to gas saturation variations than G attribute.