压裂水平井非稳态产能分析与影响因素研究——以鄂尔多斯长庆致密油为例

摘要

为研究致密油储层改造参数对压裂水平并非稳态流动特征的影响,有效预测压裂水平井产能,基于复杂缝网特征,建立了缝网双重介质压裂水平井渗流数学模型,采用有限元法对模型进行数值求解.结合长庆油田Z183井区致密油资料,通过对比不同改造方式及不同储层改造体积模式的模型计算结果,分析压裂水平井非稳态产量特征,并采用信息量分析法对压裂水平井产能影响因素进行研究.研究发现,储层改造带宽与初期线性流动阶段持续时间和压裂水平井产能正相关,与产量下降时间负相关;各主要因素按影响的显著程度从小到大依次为:主裂缝半长、水平井段长度、主裂缝导流能力和裂缝条数;次要影响因素包括基质渗透率、孔隙度和裂缝簇数等.%To account for the influence of reservoir stimulation on characteristics of unsteady-state flow and forecast the production capacity of horizontal well in tight oil reservoir,a dual-porosity model for stimulating the fracture network flow is estabhshed and the finite-element method is introduced to achieve numerical solutions.Field data of Z183 is used to study the characteristics of unsteady-state production and the corresponding impact factors of fractured well transient performance by using information analysis method.The results show that the increase of fracture network width helps decrease the decline rate of production at early time and increase well production in the life time.The main factors in descending order according to the significance are as follows:the half-length of hydraulic fracture,the length of horizontal wellbore,the conductivity of hydraulic fracture and fracture stage,all of which are the primary influencing factors.Matrix permeability,porosity and fracture cluster are the secondary influencing factors.