火山岩气藏气水动态渗吸效率研究新方法

火山岩气藏孔、缝发育且多为含水气藏,为研究火山岩气藏开发过程中的气水动态渗吸作用及其影响因素,综合运用岩石物理模拟试验、核磁共振及离心试验技术建立一套定量研究火山岩动态渗吸效率的新方法,并应用大庆火山岩气田的实际岩心试验验证方法的可行性。结果表明:动态渗吸效率随驱替速度的增加先增大后减小,在流速为0.04 mL/min时达到渗吸作用和驱替作用的动态平衡,并实现渗吸效率的最大化;渗吸效率随初始含水饱和度的增加而降低;同一岩心在不同状态下的渗吸效率不同,干岩心的静态渗吸效率最大,其动态渗吸效率次之,束缚水条件下岩心的渗吸效率最低。

A new method of researching gas-water dynamic imbibition efficiency in volcanic gas reservoir

Most of volcanic gas reservoirs are water-bearing gas reservoirs with holes and fractures.In order to find out the degree and influencing factors of the gas-water dynamic imbibition in the development of volcanic gas reservoir,a new method was established to quantitatively study the dynamic imbibition efficiency using petrophysical simulations,NMR and centrifugal experiment technology.The feasibility of this method was proved by experiments using real cores from Daqing volcanic gas reservoir.The results show that the efficiency of dynamic imbibition rate increases at the beginning and then declines with the increase of the displacement rate.The imbibition and the displacement reach dynamic balance at a flow rate of 0.04 mL/min,and the maximum imbibition efficiency is achieved at this rate.The imbibition efficiency decreases with the increase of initial water saturation.The imbibition efficiency of the same core is different in different imbibition states.The static imbibition efficiency of dry core is the highest,the dynamic imbibition of dry core takes the second place,and the imbibition efficiency of core with bound water is the lowest.