裂缝中气液二相流体临界渗流现象及其随机混合渗流数学模型研究

GAS-LIQUID TWO-PHASE CRITICAL SEEPAGE LAW IN SINGLE FRACTURE AND ITS RANDOM AND COMPOUND MATHEMATICAL MODEL

通过对裂缝中气液二相流体临界渗流现象的分析推理,建立描述这一现象的随机混合渗流数学模型。应用该模型,对出现临界渗流现象的概率分布范围、临界渗流区内气水连通团的微观分布特征以及临界渗流区内压力梯度的分布特征进行数值模拟,从而揭示这一现象产生的机制,并确定临界渗流现象在气体相对饱和度为44%～70%时都可能出现,但出现临界渗流现象的概率范围大于0.8的气体相对饱和度范围为47%～65%,在气体饱和度为57%～60%时,出现临界渗流现象的概率为1.0。

Based on analyzing the micro critical seepage phenomena of gas-liquid two-phase flow in a single fracture,a random and compound mathematical model was constructed to describe this phenomenon.Using this model,the numerical simulations of the probability distribution scope of the occurrence of critical seepage phenomenat,he micro characters of gas/water connected clusters in critical seepage district,and the characteristics of the pressure gradient in critical seepage district are all carried out.The mechanism of the gas-water two-phase critical seepage law is revealed;and the critical seepage phenomena could occur when the relative gas saturation is 44%–77%;but the probability of the occurrence of the phenomenon is above 0.8 when the gas relative saturation is 47%–65%.However,when the gas relative saturation is 57%–60%,the probability of the occurrrence of the phenomena is 1.0.