气藏采收率影响因素研究与启示——以靖边气田A井区为例

以鄂尔多斯盆地靖边气田A井区为例,采用单因素相关分析和数值模拟方法,对比研究了井网控制程度、储层物性及地层废弃压力对气藏采收率影响及其主次关系。结果表明,井网控制程度是影响采收率的首要因素,井网控制程度每增加10%,采收率提高8.5%;渗透率是影响采收率的重要因素,渗透率每增加10%,采收率平均增加6%;废弃压力对采收率亦有较大影响,废弃压力每降低10%,采收率可提高1.6%。三者对采收率影响综合排序为：井网控制程度>储层物性>废弃压力。分析认为,渗透率是储层固有属性,很难从根本改变;而废弃压力受井口外输压力和增压开采成本制约,降低幅度有限。因此,优化井网及增加井网控制程度是提高气藏采收率的有效途径。研究成果具有实践意义,可为改进气田开发方式和提高气藏采收率提供参考。

Study on influencing factors of gas reservoir recovery factor and its enlightenment:A case study of well area A in Jingbian Gas Field,Ordos Basin

Taking well area A in Jingbian Gas Field of Ordos Basin as an example,the effects of well pattern control,reservoir physical properties and formation abandonment pressure on gas reservoir recovery and their primary and secondary relations are comparatively analyzed by using single factor correlation analysis and numerical simulation methods.The results show that the control level of well pattern is the primary factor affecting the recovery factor,and the recovery factor increases by 8.5% for every 10% increase in the control level of well pattern.Permeability is an important factor that affects the recovery factor,for every 10% increase in permeability,the average recovery factor increases by 6%.The abandonment pressure also has a great influence on the recovery factor,and the recovery factor can be increased by 1.6% for every 10% reduction of the abandonment pressure.The comprehensive order of the influence of the three factors on the recovery factors is:Well pattern control degree>reservoir physical properties>abandonment pressure.The study shows that permeability is the inherent property of the reservoir and it is difficult to change fundamentally.However,the abandonment pressure is limited by wellhead export pressure and pressurized production cost,and the reduction range is limited.Therefore,optimizing well pattern and increasing the control level of well pattern are effective ways to improve gas reservoir recovery factor.The research results are of practical significance and can provide references for improving the development mode and increasing the recovery factor of gas reservoirs.