川中地区须家河组低渗透砂岩气藏储层综合评价方法

An integrated evaluation method of Xujiahe low-permeability sandstone gas reservoirs in Middle Sichuan Basin

根据四川盆地川中地区上三叠统须家河组低渗透砂岩含水气藏储层、渗流及开发的静、动态特征,构建了渗透率、孔隙度、含气饱和度、有效储层厚度、主流喉道半径、阈压梯度和可动水饱和度的储层分类评价7参数体系,应用模糊分析法和灰色关联度分析法建立了相应的储层综合分类评价方法,对18口气井井控储层进行了分类评价,并与常规评价结果和气井产能进行了对比分析,进一步对目标区块进行了区块储层评价。结果表明:新的储层分类评价方法准确度达到90%,比常规评价方法提高了40%,验证了该方法的可靠性和实用性。该研究成果对于川中地区须家河组低渗透砂岩含水气藏富集区优选具有指导作用。

According to the characteristics of formation,seepage and static and dynamic performance of Xujiahe low-permeability sandstone water-bearing gas reservoirs in Middle Sichuan Basin,a classified evaluation system is first established with 7parameters including permeability,porosity,gas saturation,effective reservoir thickness,mainstream throat radius,threshold pressure gradient and movable water saturation.Then,based on fuzzy analysis and gray correlation analysis,an integrated evaluation method is proposed to make a classified evaluation on the reservoirs with 18gas wells under control.The evaluation results are compared with the conventional ones and gas well yield,and thus to evaluate the reservoirs among the target blocks.The comparison results show that the accuracy rate of the new classified evaluation method reaches 90%,which is 40% higher than that by the conventional method.Thus,the reliability and practicability of this method are validated.To sum up,the research achievement provides an important guidance for enrichment zone optimization in Xujiahe low-permeability sandstone gas reservoirs.