低渗透油藏垂直井未来流入动态的预测

THE PREDICTION OF FUTURE IPR OF VERTICAL WELLS IN LOW PERMEABILITY RESERVOIRS

针对低渗油藏存在启动压力梯度,动态预测非常困难的问题。推导了具有启动压力梯度的溶解气驱油藏未来流入动态预测关系式,分析得出油井的采油指数和流压之间存在线性关系,且不同地层压力下的流入动态通过最大采油指数联系了起来。同时,以采液指数为桥梁,推导了三相流未来流入动态关系式。将此预测方法应用于现场实际,通过与其他预测方法进行对比,得出方法可信度高。23个测试点预测数据显示,平均误差在11%以内,对油田的生产开发具有指导意义。

With common permeability reservoirs coming into their low productivity periods,the development of low-permeability reservoirs becomes more vital.But the performance analysis prediction of reservoirs is very difficult because threshold pressure gradient.Based on investigation results,the prediction of inflow performance in low-permeability solution-gas-drive reservoirs existing threshold pressures is presented.There is a linear relation between productivity index and bottomhole flow pressure.The inflow performances in different reservoir pressure are connected with ultimate PI.According to the fluid PI,a new calculating method that predicts future three-phase flow performance of vertical wells in low-permeability reservoir is established.The application of 23 sets of oil field data to validate the models shows that the average calculation errors is within 11%.The established predicting future IPR is suitable for different cases and can be widely used in practice.