压裂火山岩气井不对称裂缝产能模型研究

A research on the asymmetric fracture productivity models for fracturing volcanic gas wells

随着松辽盆地徐深气田火山岩气藏投入开发,急需开展压裂火山岩气井产能的研究,从而指导气田开发。基于气体单相稳定渗流规律,针对压裂后不对称裂缝特征,引入保角变换和等值渗流阻力原理,建立了压裂火山岩气井不对称裂缝产能模型,同时分析了火山岩气井压裂裂缝的不对称性对产能的影响。结果表明:火山岩气井单条裂缝产能与不对称性没有关系,随着裂缝长度的增加,产能增加幅度相同;对于压裂双裂缝气井来说,随裂缝长轴长度增加产能增加的幅度最大,随裂缝短轴长度增加产能增加的幅度最小;对称裂缝产能模型是不对称裂缝产能模型的特例,不对称裂缝产能模型具有更广泛的适用性。

With the development of volcanic gas reservoirs of Xushen gas field in the Songliao Basin,the researches of fracturing volcanic gas wells productivity are urgently needed to guide the development of this gas field.On the basis of the gas single-phase steady seepage law,and according to the characteristics of asymmetric fractures after fracturing,we introduced the principles of conformal transformation and equivalent flowing resistance to establish the asymmetric fractures productivity model for fracturing volcanic gas wells,and analyzed the impact of the asymmetry of fractures after volcanic gas wells being fractured on the productivity.The results show that ①the single-fracture productivity has no relation to the asymmetry;②for the fracturing double-fracture gas wells,the increasing extent of productivity,which is the greatest along with the increasing of fracture long axis length,but the smallest along with the increasing of fracture short axis length;and ③the symmetric fracture productivity model is only a special case of the asymmetric fracture productivity models,so the latter is more widely used.