基于岩石物理定量表征关系的砂岩净厚度预测

Prediction of sandstone net thickness based on petrophysical quantitative relationship

为克服基于地震属性预测砂岩净厚度方法中地震属性的地质-地球物理意义不明确的难题,提出基于泥质含量和净毛比岩石物理关系的砂岩净厚度预测方法。该方法首先预测泥质含量,通过岩石物理交会建立泥质含量的定量表征公式,然后利用地震反演弹性参数计算泥质含量体,有效解决了常规基于拟声波曲线反演泥质含量中地震正演意义不明确的难题;然后预测砂岩净毛比分布,通过岩石物理建立净毛比和泥质含量的定量表征公式,据此计算净毛比平面分布;最后结合砂岩毛厚度和净毛比计算砂岩净厚度。以上方法应用于靶区S油田砂岩储层净厚度预测,预测结果较为准确,可有力支持油田勘探、开发生产。

In order to overcome the problem that the geological geophysical significance of seismic attributes is not clear in the method of predicting the net thickness of sandstone based on seismic attributes,a method for predicting the net thickness of sandstone based on the petrophysical relationship between shale content and net to gross ratio is proposed.This method first predicts the shale content,establishes the quantitative characterization formula of the shale content through rock physical intersection,and then calculates the shale content body using seismic inversion elastic parameters,effectively solving the problem that the seismic forward significance of shale content in conventional inversion of shale content based on pseudo acoustic curve is not clear.Then,the net to gross ratio distribution of sandstone is predicted,and the quantitative characterization formula of net to gross ratio and shale content is established through petrophysics,according to which the plane distribution of net to gross ratio is calculated.Finally,the net thickness of sandstone is calculated based on the gross thickness and net to gross ratio of sandstone.The above methods are applied to the prediction of net thickness of sandstone reservoir in S oilfield in the target area,and the prediction results are relatively accurate,which can strongly support the exploration,development and production of the oilfield.