测压信息确定油藏非均质性方法研究

Methods for Determining of Reservoir Heterogeneity by Utilizing Pressure Testing Information

在Oliver等人研究工作基础上,引入瞬时渗透率,建立了平面非均质油藏模型,利用扰动理论和拉普拉斯变换,推导了不稳定井底压力及压力导数的近似解析解,在此基础上建立了地层径向渗透率剖面的递归算法。方法中定义的瞬时渗透率是随时间变化的,是测试时间对应的探测区域内渗透率的调和平均。以此瞬时渗透率为基础的渗流模型及递归算法,突破了Oliver等人油藏渗透率随径向距离不能变化太大的限制,能更好地分析油藏的渗透率非均质性,拓展了试井资料应用范围。

Based on Oliver theory,radial heterogeneous reservoir model was established by defining instantaneous permeability to deduce universal pressure and pressure derivative solution on the basis of disturbance theory and Laplace transform method,a recursive algorithm was derived to confirm radial permeability profile of reservoirs.Instantaneous permeability defined in the method changed with time,it was a mediation average on permeability distribution between the wellbore and a radius of investigation.The model and recursive algorithm based on instantaneous permeability concept break the limit that permeability changes little with radial space,can confirm reservoir heterogeneity more accurately,makes well test information more useful.