基于模型地震反演储层预测技术的应用——以牛圈湖油田西山窑组为例

牛圈湖油田西山窑组(J2x)属于低孔、低渗、低压的"三低"油藏,储层非均质性强,储层预测尤为重要。根据测井曲线的对比及交会分析,选择了自然伽马曲线和声波时差曲线来构建具有声波量纲的拟声波曲线,采用宽带约束模拟退火非线性全局寻优反演方法进行了储层预测。通过3种测井资料(10%地震和90%测井、30%地震和70%测井、50%地震和50%测井)约束程度对比,发现使用10%地震和90%测井参与程度的反演结果精度最高,表明基于模型的地震反演技术可获得高分辨率的地层波阻抗资料,并能有效地区分储层与非储层。根据储层预测结果与实钻结果的对比,分析了误差原因和存在的问题。

Application of seismic inversion technique based on model to reservoir prediction:A case study from Xishanyao Formation in Niuquanhu Oilfield

The reservoir of Xishanyao Formation(J2 x) in Niuquanhu Oilfield is characterized by low porosity,low permea-bility,low pressure and strong heterogeneity,so reservoir prediction is particularly important.Through contrast and analysis of well logs,natural gamma ray curve and sonic log curve were selected to build up a sonic-dimensional pseudo-acoustic curve,and broadband constrained simulated annealing nonlinear global optimization inversion method was applied to carry out reservoir prediction.Through comparing three degrees of constraint of logging data(① 10% seismic and 90% logging,② 30% seismic and 70% logging,③ 50% seismic and 50% logging),it is found that the inversion result from using 10% seismic and 90% logging is of the highest accuracy.It shows that using seismic inversion technique based on model can obtain high-resolution impedance information,and effectively distinguish reservoir from non-reservoir.According to the comparison between predicted and actual drilling results,the error causes and problems were analyzed.