考虑蚓孔的碳酸盐岩酸化产能计算新模型

A Novel Well Productivity Model of Carbonate Reservoir Matrix Acidizing Considering Wormhole

针对碳酸盐岩基质酸化产能常规计算方法未能考虑酸蚀蚓孔数量和酸蚀蚓孔渗流特性影响这一问题,开展了考虑蚓孔的碳酸盐岩酸化产能的研究,研究中采用了径向蚓孔生长理论模型和蚓孔区等效渗透率模型,建立了考虑蚓孔的碳酸盐岩酸化产能计算新模型。由室内碳酸盐岩岩芯15%盐酸驱替实验结果,优选了最优的注酸速度及蚓孔突破时酸液注入的孔隙体积倍数,计算了有效主蚓孔的长度和直径、蚓孔区等效渗透率和酸化产能,结果表明新模型计算的产能与真实定压求产的产能相当,为碳酸盐岩酸化产能预测提供了一种新的理论方法。

We studied the wormhole effect on the well productivity which conventional well productivity model of matrix acidizing in carbonate reservoir did not take into consideration.On the basis of the wormhole growth model in radial geometry and the equivalent permeability model,this paper established a new well productivity model considering wormhole.Based on the laboratory experiment data of carbonate core displacement by 15%HCl,we selected the optimal acid injection velocity and the optimal pore volume to breakthrough,and calculated the effective dominant wormhole length and diameter and equivalent permeability in post-stimulation area near wellbore.Then we calculated the well productivity,and compared it with the real productivity,and the result shows that when considering the wormhole,the new model is accurate and reliable.This research presents a new method to predict the well productivity for matrix acidizing in carbonate reservoir.