凝析气藏水平井试井分析

Analysis of horizontal well testing of condensate gas reservoirs

受复杂的相态变化和流动特征影响,凝析气藏水平井试井分析一直是凝析气藏动态描述的难点。通过三维全组分模拟器,建立一个理想的均质等厚的凝析气藏水平井模型,设置长时间的压力降落和压力恢复测试序列,研究凝析气藏水平井测试期间的流动规律,为试井分析中的流动阶段识别和参数解释提供依据。研究表明,反凝析影响下的凝析气藏水平井典型试井曲线不同于理想的干气流动,反凝析造成的凝析油饱和度增加、气相相对渗透率降低和表皮系数的增加在试井曲线上一一对应,流动规律的认识验证了不同流动阶段在典型试井曲线上的反应。

Under the influence of the complicated phase behavior change and flow property,horizontal well testing analysis has been a difficult in dynamic description of condensate gas reservoirs. By means of 3D full composition simulator,a model for horizontal wells in homogeneous gas reservoir with constant thickness is established and testing sequence for long-term pressure breakdown and pressure buildup are set up,thus the flow law during horizontal well testing in condensate gas reservoirs can be studied,which provides references for flow stage identification and parameters interpretation. The result shows that the typical testing curve of condensate gas reservoir under the influence of retrograde condensation is different from that under dry gas flow. The increase of condensate oil saturation caused by retrograde condensation,the decrease of gas relative permeability,and the increase of skin factor are corresponding to testing curve. The understanding of flow law has been verified by the behavior of different flow stage at typical testing curve.