川东地区飞仙关组鲕滩储层为孔隙型储层，孔隙及喉道是油气储存及渗流的主要场所和通道，孔隙度的大小直接控制了天然气的储量及产能，对鲕滩储层的孔隙度进行高精度预测具有十分重要的意义。我们使用由Wyllie时间平均方程得到的孔隙度与速度的经验公式，结合本区实际钻、测井资料得到本区的经验公式，通过与其它地区通用的孔隙度估算公式进行对比分析发现，二者对应关系很一致，反映了孔隙度随速度变化的规律相近。通过应用地震资料反演得到的速度资料对鲕滩储层的孔隙度估算表明，预测的孔隙度大小不仅与实测天然气产量有明显的对应关系，而且与构造背景也有较好的对应关系，结果总体上符合地质规律，与构造有较好的对应关系，同时局部孔隙度异常较明显。研究结果表明，本方法是一套预测鲕滩储层孔隙度的有效方法，具有重要的实用价值。%The oolitic beach reservoir in Feixianguan Formation in East Sichuan is a porous reservoir,pores and throats being the places and passages for hydrocarbon storage and flow;and the reserves and productivity of natural gas are directly controlled by the magnitude of porosity.Therefore it is very important to predict the oolitic beach reservoir porosity with high accuracy.On the basis of the empirical equation expressing the relation between porosity and seismic velocity derived form Wyllie time average equation,the empirical equation suitable to this region was obtained in combination with the practical drilling and logging data in this region.Through camparing and analyzing the porosity estimation equation commonly applied to the other regions,it is found that a good correspondence is kept up between both of them,which shows that the rule of the change of porosity with seismic velocity is similar.By means of estimating the porosity of oolitic beach reservoir by the velocity data derived from seismic data inversion,it is indicated that the magnitude of porosity predicted is not only obviously corresponding to the natural gas production measured but also well corresponding to the structural setting.In other words,the result tallies with the geological law,i.e.the porosity is well related to the structural portion,meanwhile the obvious porosity anomalies are found regionally.Through research it is shown that this method is an effective method of predicting oolitic beach reservoir porosity,being of important practical value.
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