含多条垂直裂缝的压裂气井产能研究

Study on productivity performances of horizontal fractured gas well with many vertical fractures

根据压裂水平气井的渗流过程,对压裂水平气井的压降进行了分析,将气体从地层流入水平井底的压降分为三部分:一是气体从地层流入裂缝,通过复位势理论和势的叠加原理得出了有关产能的压降公式;二是从裂缝流入水平井段,通过对裂缝微元体的分析得出有关裂缝参数的产能压降公式;三是气体从水平井段指端流入水平井的跟端,通过动量定理得出了压降关系。这样就得出了产量与裂缝半长和裂缝条数等参数的关系模型,由于整个模型的建立都是通过严格的解析方法来得出的,因而该方法与目前所用的方法相比,准确性较高。

By analyzing the hydrauliclly fractured horizontal gas well,the pressure drop of gas seeping from the formation into wellbore is divided into three sections. In the first section,the pressure drop formula about productivity from the formation into fractures is got by the potential function and superposition principles.In the second section,the pressure drop formula about productivity from the fractures into horizontal well section is obtained by the analysis on fracture microelements.In the third section,the pressure drop formula from fractures into horizontal wellbore is obtained by momentum theorem.So the models between output and fracture half- length,fracture number and so on is educed. Because the model is constructed basing on strict analytical method,its accuracy is higher than the existing methods.