考虑启动压力梯度低渗双重介质油藏垂直裂缝井试井模型  

Well Test Model of Vertical Fractured Wells in Double Porosity Reservoir with Low Permeability with Consideration of Startup Pressure Gradient

作　　者：刘永良[1] 徐艳梅[2] 刘彬[1] 徐艳霞[1] 黄伟岗[2] 

机构地区：[1]西南油气田分公司川东北气矿,四川达州635000 [2]中国石油勘探开发研究院廊坊分院,河北廊坊065007

出　　处：《油气井测试》2010年第5期5-8,共4页Well Testing

基　　金：教育部博士学科点新教师类基金资助(20095122120012)

摘　　要：常规低渗透双重介质油藏垂直裂缝井试井模型均未考虑启动压力梯度的影响。根据低渗透双重介质地层水力压裂后的渗流特点,结合Warrant-Root模型,建立了考虑启动压力梯度的低渗透双重介质油藏双线性流数学模型,推导出其在Laplace空间的解析解。通过Stehfest数值反演获得了试井样板曲线,讨论了主要油藏参数和工程参数对样板曲线的影响。研究表明,启动压力梯度对低渗透垂直裂缝井试井曲线影响显著,表现为无因次压力及压力导数曲线后期呈上翘趋势,且随启动压力梯度增大,压力及压力导数曲线上翘幅度越大,上翘的时间也越早。None of conventional well test models of vertical fractured well in double porosity reservoir with low permeability take the influence of startup pressure gradient into account.Bilinear mathematical model of double porosity reservoir with low permeability and taken startup pressure gradient into account is established based on the flow characteristics of fractured well in double porosity reservoir with low permeability and integrating Warrant-Root model;its analytic solution in Laplace space is derived.Type curves are obtained by Stehfest numerical inversion,and influence of the main parameters of reservoir and engineering to type curves is discussed.The study result showed that the startup pressure gradient influences seriously well test curves of vertical fractured wells in reservoirs with low permeability,and the influence is represented by going up of dimensionless pressure and its derivative curves in late time,the higher the startup pressure gradient,the bigger the range of going up and the earlier the going up appears.

关 键 词：启动压力梯度 双重介质油藏 低渗透 垂直裂缝 有限导流 双线性流 

分 类 号：TE312[石油与天然气工程—油气田开发工程]