测井约束反演预测白云岩储层实践

On Dolomite Reservoir Prediction in Well Log-constraint Seismic Inversion

大港探区歧口凹陷西南缘沙一段下部发育白云岩储层与油页岩互层产出,是大港油田重要的增储领域之一。该区白云岩储层薄,裂缝发育,整体具有连片的特点。在测井曲线上表现为"三低两高"特征,即AC、GR和CN呈现低值状态,DEN和RT呈高值显示。通过分析可知研究区大部分井的AC、DEN、GR、RT任意一种曲线都无法准确、清晰地识别白云岩。为此,利用白云岩在不同曲线上的反应特征,通过不同的数学模型,将白云岩的特征曲线值适当放大;同时,尽可能压低非白云岩岩性的曲线值,重构出一条拟声波曲线,利用稀疏脉冲地震反演技术进行储层预测,从而有效识别白云岩储层的空间分布,取得了很好的应用效果。

In the southwest margin of Qikou sag of Dagang exploration area ,dolomite reservoirs an d oil shale cross layer output ,in the lower part of first member of Shahejie formation ,are one of the most important increase storages in Dagang oil field .The characteristic of the dolo-mite in logging curve is”three low two tall ” .The values of AC , GR and CN are low and the values of DEN and RT are high .Through the analysis AC , DEN , GR , RT of most study wells ,none of the curves can identify the dolomite accurately and clearly .The reaction characteristics of dolomite on different curves are used ,through the different mathematical models ,to make the curve value of dolomite’s characteristic appropriate magnification .At the same time ,the curve value of non dolomite’s is made minimum low to reconstruct Pseudo -acoustic wave .Sparse pulse inversion technique is used to predict the reservoir and recognize dolomite reservoir space distribution effective-ly .It is of very good effect .