裂缝-孔隙型砂岩气藏可动储量综合界限

Comprehensive Limits of the Movable Reserves in Fractured-Porous Sandstone

明确可动储量界限是确定气藏可动储量和难动储量的基础。综合应用裂缝性气藏等效介质模拟方法和单井经济极限评价方法确定了川西地区平落坝须二段裂缝-孔隙型砂岩气藏不同裂缝发育程度储层的可动储量综合界限。结果表明,基质物性对单井累计产气量影响最为显著,而裂缝角度影响很小;基质渗透率越低,裂缝密度对单井累计产气量的影响越大;天然裂缝越发育,可动储量的综合界限越低;对于裂缝不发育储层,可动储量的综合界限为:覆压渗透率下限0.008 mD,含水饱和度上限42%,孔隙度下限6.4%。

The identification of limits in the movable reserves of a reservoir is the basis for the determination of its movableand immovable reserves.Through the simulation of fractured gas reservoirs using equivalent medium models,and evaluationsbased on the economic limits of single wells,we have identified the comprehensive limits of movable reserves in reservoirs withvarying levels of fracture development in the XU-2fractured porous sandstone gas reservoir of Pingluoba in Western Sichuan.The results of this study have shown that the properties of the matrix have the most significant impact on the cumulative gasproduction of a single well,whereas the fracture angle only has a very small effect.The influence of fracture density on thecumulative gas production of a single well was found to increase with decreases in matrix permeability.The comprehensivelimits of the movable reserves also appear to decrease as natural fractures develop further.In reservoirs without developedfractures,the comprehensive limits of its movable reserves are as follows:its lower limit of permeability under overburdenpressure is0.008mD,while its upper limit of water saturation is42%,and its lower limit of porosity is6.4%.