【摘要】 针对定量计算页岩气储层水平井压裂后含水对产气量影响程度的问题,应用渗流力学、油藏数值模拟及油层物理学等理论与方法,建立了考虑解吸-吸附、扩散、滑脱及应力敏感的双重介质气-水两相渗流模型,并进行了差分离散及方程组系数线性化处理,建立了数值模型。利用新模型对页岩气储层压裂水平井进行了气、水产量的预测,并对比分析了不同含水饱和度、压裂缝网参数、扩散、滑脱及应力敏感等对气井生产的影响。结果表明,原始含水饱和度决定产量回升幅度和稳产时间,原始含水饱和度越小,压裂液返排率对产量影响越大;当裂缝导流能力和缝网区域半长较大时,再提高其增产幅度会减小;扩散作用弱于滑脱作用,应力敏感作用要明显大于扩散和滑脱,增产稳产目标要重点考虑应力敏感。更多还原

【Abstract】 It has been an important scientific issue to quantitatively calculate the influence degree of water content on gas output after horizontal well fracturing in shale gas reservoirs.The flow mechanics,reservoir numerical simulation and petro-physics,and other basic theories and methods were applied to establish a dual-media gas-water two phase porous flow model considering absorption-desorption,diffusion,detachment and stress sensitivity.Meanwhile,differential dispersion and equation coefficients linearization were performed to obtain a numerical model.Through case application,this newly created model was applied to predict water and gas output and comparatively analyze the influences of water saturation,fracture network parameters,diffusion,detachment and stress sensitivity on gas well production.The results show that the output recovery magnitude and stable production duration are determined by original water saturation.The smaller the original water saturation is,the larger the influence of fracturing fluid flow back rate on production will be.When fracture conductivity and the half length of fracture network are large,the increase of both values will lead to the reduction of yield rate.The diffusion effect is weaker than detachment effect,while the effect of stress sensitivity is significantly greater than that of diffusion and detachment.Therefore,stress sensitivity should be focused for the target of yield increase and stabilization.更多还原