摘要
多级酸压、压裂等分层改造后的垂直合采井井周储层往往存在纵向非均匀的改造边界,为了探究改造边界纵向非均匀性对储层流体流动和生产井井底压力的影响,建立了考虑纵向非均匀复合半径(Vertical Non-Uniform Composite Radii,VNCR)的垂直合采井井底压力响应模型。通过Laplace空间变换、Bessel函数、克莱默法则和Stehfest数值反演方法得到了井底压力解,绘制了压力响应特征曲线并划分了流动阶段,分析了VNCR的空间分布类型对井底压力响应和储层流动的影响。结果表明:VNCR会引起储层出现新的过渡流和径向流,造成储层出现三区径向复合储层的压力响应特征,且新的径向流由VNCR在储层的厚度占比决定;VNCR空间分布类型对井底压力响应的影响存在多解性,仅通过井底压力和压力导数不能得到VNCR确切的空间分布,但可以确定VNCR的最小和等效边界、储层占比、内部储层体积大小等信息。结论认为:分层改造储层的体积和等效边界值可以通过井底压力响应得到,但具体的空间分布不能仅依靠压力响应获得;当压力响应出现三区径向复合储层特征时,应当格外谨慎地选择储层模型进行解释。
The multi-stage acid fracturing,fracturing,and other layered stimulation often induced vertical nonuniform composite boundaries near commingled vertical production wells.To explore the influence of vertical non-uniformity of the stimulation boundaries on the flow in reservoir and pressure response of production well,the bottom-hole pressure response model of vertical commingled wells considering vertical non-uniform composite radii(VNCR)was established.Through the Laplace transformation,Bessel function,Cramer’s Rule,and Stehfest inversion method,the bottom-hole pressure solution was obtained,the pressure response type curve was drawn and the flow regime was divided,and the influence of the VNCR distribution on the bottom-hole pressure response and flow regimes was analyzed.The results show that:Firstly,VNCR will cause new transitional flow and radial flow in the reservoir,resulting in pressure response characteristics of three-zone radial composite reservoir,and the new radial flow is determined by the proportion of VNCR thickness in the reservoir thickness.Secondly,there are multiple solutions to the impact of VNCR distribution on reservoir pressure response.Thirdly,the true VNCR distribution type cannot be obtained only by the bottom-hole pressure and pressure derivative curve,but the minimum,equivalent value,thickness ratio,equivalent volume of VNCR can be captured.It is concluded that the equivalent volume and equivalent boundary value of VNCR rather than the true distribution of VNCR can be captured by the bottom-hole pressure response.The reservoir model should be selected with extreme caution for interpretation when three-zone radial composite reservoir characteristics appear in the pressure response.
作者
史文洋
程时清
孙兵
张睿
高敏
SHI Wen-yang;CHENG Shi-qing;SUN Bing;ZHANG Rui;GAO Min(Stuate Key Laboratory of Petrolewm Resources and Prospecing,China University of Petroleum(Beijing),Beijing 102249,China;Petroleum Exploration&Production Research Institute,SINOPEC,Beijing 100083.Chima;No.4 Oil Production Planl,Changqing Oilfield Company of CNPC,Yulin 718500,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2021年第4期481-491,共11页
Natural Gas Geoscience
基金
国家科技重大专项“高含硫气藏安全高效开发技术(三期)”(编号:2016ZX05017)
中石化科技部十条龙科技攻关项目“超深高含硫气田提高采收率技术”(编号:P18062)联合资助。
关键词
径向复合储层
合采储层
复合半径垂向非均匀
压力响应
试井多解性
Composite reservoir
Commingled reservoir
Vertical non-uniform composite radii
Pressure response behavior
Well test multi-solution
