钻柱测试“压衰”的原因分析

从理论上分析了钻柱测试中产生“压衰”的原因：不渗透边界，远处物性变差，双重介质储层，物性存在很大差异的多层合试都可引起“压衰”现象，只要恢复时间足够长，上述原因导致的“压衰”可消除；对于非自喷井测试资料，若用Ｈｏｒｎｅｒ法分析，且Ｈｏｒｎｅｒ生产时间采用实际生产时间时，通常会产生“压衰”，通过采用非自喷井解释方法。其“压衰”现象会自动消失；压力系统不同的多层合试可产生“压衰”。

REASON ANALYSIS OF PRESSURE DECLINE IN DRILLING STEM TEST

In this paper,pressure decline reasons were analysed in drilling stem test.Pressure decline resulted from the for-mation with non-flow boundaries.or the formation with matter characters changing bad in distant place from well.ordual medium reservoir,or multi-layered reservoirs with large difference in matter characters in DST.So long as shut-in time was enough long.the pressure decline resulted from the aforementioned reasons would vanish.Nonartesian welltest data were interpreted with Horner's method and taking real flowing time to be Horner producing time, whichmight lead to pressure decline. it might vanish with nonartesian well interpretation methods.Pressute decline was alsocaused by the two-layered reservoir with different pressure systems in DST.