渤海典型薄互层油藏水驱动用及关键开发指标研究

Study on Water Flooding and Key Development Indexes of Thin Interbedded Reservoir

P油田整体为典型的薄互层油藏,主要特点是储层厚薄不均、薄层发育、储层横向变化快、储层连通性差、测试及生产动态资料少,导致真实水驱动用程度预测难度大。水驱油藏中注采对应率的高低直接决定了水驱动用程度,对油藏关键指标如采收率、递减率和含水上升率的预测精度有重要影响。首先基于地质精细小层对比,从薄互层油藏注采对应率出发,得到油田平均静态注采连通率在75%左右,进一步分析油田的随钻测压资料及实际生产数据,油藏实际动态注采对应率为70%;通过建立能够代表油田薄互层油藏地质特征的典型数值模型来判断注采对应率对递减率、采收率、含水上升率的影响。研究结果表明,在相同的产液速度条件下,注采对应率越高,递减率越小;反之,则递减率越大。随着注采对应率的提高,油田采收率和含水上升率也相应提高。

As a whole,P oilfield is a typical thin interbedded reservoir,which is characterized by uneven reservoir thickness,thin layer development,rapid lateral change of reservoir,poor reservoir connectivity,and less testing and production performance data,so it is difficult to predict the real water flooding degree.The corresponding rate of injection and production in water flooding reservoir directly determines the water flooding degree,which has an important impact on the prediction accuracy of key indicators such as recovery rate,decline rate and water cut rise rate.Based on the comparison on the geological fine layers,starting from the injection production corresponding rate of thin interbedded reservoirs,the average static injection production connectivity rate of the oilfield is about 75%.Further analysis of the pressure measurement while drilling data and actual production data shows that the actual dynamic injection production corresponding rate of the reservoir is 70%.Through the establishment of a typical numerical model which can represent the geological characteristics of thin interbedded reservoir,the influence of injection production corresponding rate on decline rate,recovery rate and water cut rise rate is judged.The results show that under the same liquid production rate,the higher the injection production corresponding rate,the smaller the decline rate;On the contrary,the greater the decline rate.With the increase of the injection production corresponding rate,the oil recovery rate and water cut rise rate are also increased.