不同渗透性地层气井产能试井综合评价——以国外F气田为例

Comprehensive Evaluation of Gas Well Deliverability Testing in Formations With Different Permeability formation by Taking Examples of “F" Foreign Gas Field

国外F气田地层渗透率相差几个数量级,产能试井前清井效率明显受地层渗透率影响。12层产能试井结果表明,不合理的清井制度会导致产能方程系数B为负值,而指数N大于或约等于1,导致计算无阻流量误差较大。多层合试情况下,层间非均质差异也会对产能试井造成不同程度的影响。通过总表皮和渗透率的交会图可以评价污染表皮对射孔参数的敏感性,引入单位无阻流量的概念,并制作其与渗透率的交会图可以定性评价中高渗层的改造潜力。此研究分析,对合理制定产能试井制度和优选射孔方案有较强的指导意义。

F gas formation permeability vary widely abroad,productivity well test before well cleanup efficiency significantly affected by the formation permeability. Well testing results of 12 layers in ' F' Foreign gas field show that the irrational regime for well cleanup can result in the negative deliverability equation coefficient B and the index N more than 1 or approximately equal 1,to cause AOFP having greater inaccuracy. In the case of multi-layer test,the difference between the non-homogeneous layers has an effect on deliverability testing in some degrees. By compassion,it is found that the improvement of the total skin factor of reservoir in F gas field is comparatively sensitive to hole depth. Through the cross plot of pseudo skin and permeability can evaluate the sensitivity of the real skin to perforation parameters. The unit AOFP was defined and by the cross plot of the unit AOFP and formation permeability can qualitatively evaluate the reconstruction potential of middle-high permeable zones. Analysis developed in this paper has a strong significance for the reasonable deliverability testing design and the optimization of perforating program.