无措施定向井表皮系数为负值原因分析

Analyzing the causes of negative skin factors in directional wells without stimulation

矿场试井解释经常出现无措施定向井表皮系数解释为负值的情况,这与常规的无限大均质油藏试井解释理论相矛盾。在对渤海油田大量试井实例分析的基础上,结合试井解释理论分析总结出了径向复合油藏、高渗透条带连通井筒油藏、层间物性差异大合采油藏等3类可能导致负表皮系数的油藏模型,并以渤海油田实例数据验证了理论分析的正确性,对矿场试井解释具有一定的参考价值。

Negative skin factors often occur in the well testing interpretation for directional wells without stimulation, but this is in contradiction with the traditional interpretation theory of well testing in an infinite homogeneous oil reservoir. By analyzing a lot of well testing examples in Bohai oilfields, three types of oil reservoir model that may result in negative skin factors were summarized, including the radial composite reservoir, the reser- voir in which wellbores are connected through high permeable zones and the commingled producing res- ervoir with great inter-zone differences in petrophysi- eal property, and the soundness of this theoretical a- nalysis was validated by the data from Bohai oilfield examples, providing a certain reference for the well testing interpretation in other oilfields.