摘要
考虑体积压裂水平井不同区域渗流特征(裂缝控制外区-裂缝控制内区-压裂水平井),建立了储层-裂缝-井筒耦合流动模型,应用Laplace变换及Stehfest数值反演,给出并分析了压力动态特征曲线。结果表明:基于压力导数曲线斜率,可以将体积压裂水平井压力传播过程划分为7个阶段:(1井筒储集控制阶段;2裂缝内径向流阶段;3裂缝及储层双线性流阶段;4裂缝干扰前线性流阶段;5裂缝干扰过渡流阶段;6裂缝内区线性流阶段;7裂缝外区拟径向流阶段)。同时,结合目标区块地质特征,分析了压裂参数对各阶段压力传播特征影响。结果表明:裂缝导流能力主要影响缝间干扰前早期流动特征,持续时间约200 h;裂缝条数主要影响缝间干扰出现的时间,持续时间约1 000 h;裂缝半长几乎影响整个生产前期与中期流动阶段,影响时间可持续至10 000 h。因此对于目标区块致密储层而言,建议首先优化裂缝半长,其次为裂缝条数,最后为导流能力。研究将对压力传播阶段识别、生产动态解释及裂缝参数优化提供理论基础。
Considering the hydraulically fractured horizontal wells in different flow regions（ fracture control region-fracture control within the region- fractured horizontal wells）,a model coupling of reservoir,fracture and wellbore coupling flow is established. And the dynamic characteristic curves of pressure are presented by using Laplace transform and Stehfest numerical inversion. The results show that： based on the slope of the pressure derivative curve,the pressure transient process of hydraulically fractured horizontal wells can be divided into seven stages.（ 1 Wellbore Storage stage,2 radial flow stage in hydraulic fracture,3 Bilinear flow stage in fracture and reservoir,4 Linear flow stage before interference between fractures,5 Transition flow stage during interference of fractures,6 Linear flow stage of fracture region,7 The pseudo-radial flow stage of fracture region）. Besides,considering the geological characteristics of the reservoir,the influence of fracture parameters on the pressure transient characteristics is analyzed. Results show that,the early flow characteristics before fracture interference is mainly affected by the fracture conductivity,and the duration is about 200 h; The fracture half-length has almost effect on the whole production stage and the mid flow stage,and the impact time can be sustained to 10 000 h; Therefore,for the tight reservoir,it is suggested that the first optimization is the fracture half-length,and then the number of the fracture,the last is the conductivity. This study will provide a theoretical basis for the identification of pressure transient stage,production dynamic interpretation and optimization of fracture parameters.
出处
《科学技术与工程》
北大核心
2016年第15期84-91,110,共9页
Science Technology and Engineering
基金
国家"十三五"科技重大专项(2016ZX05039)资助
关键词
致密储层
体积压裂
水平井
压力传播
解析模型
tight reservoir
volume fracturing
horizontal well
pressure transmission
analytical model
