致密气藏岩石应力敏感对气水两相渗流特征的影响

致密气藏岩石孔隙小,喉道结构复杂,一旦骨架有效应力发生变化,骨架颗粒与孔喉结构的原始关系也发生变化,导致气水两相渗流通道发生变化,孔隙度、渗透率进一步降低,产能受到严重影响。通过实验深入研究致密储气层基质岩心和裂缝岩心在不同围压下应力变化导致气水两相流体的相对流动能力变化趋势,有利于认清致密气藏储层流体的渗流规律,并对其合理产能做出准确的评价。以长庆致密气藏P1s、P2h储层岩心为例,基于应力敏感实验,讨论了岩石渗透率应力敏感对致密储气层气水两相流动及产能的影响。

Influence of rock stress sensitivity in tight gas reservoir on characteristics of gas/water two phase flows

There are small ton effective stresses changed changed. As a result, channels pore and complicated structures of pores and throats in tight gas reservoirs. Once the skele- , original relationship between skeleton grains and structures of pores and throats also of gas/water two phase flows also changed, and porosity and permeability of the reservoirs further reduced. These changes seriously affected productivity of the tight gas reservoirs. For matrix cores and fractured cores of tight gas reservoirs, it was studied to the changed trend of gas/water flow ability caused by stress changes under va- rious confining pressures. Lab results are favorable to recognizing the flow rule of the tight gas reservoirs and accurately e- valuating reasonable productivity. Let us take cores of Changqing tight gas reservoirs, P,s,P2h, for examples. According to rock stress sensitive experiments, this paper presents the effect of stress sensitivity of rock permeability on gas/water two phase flow ability and productivity of the tight gas reservoirs.