Abstract: In hydraulic fracturing,formation may be damaged in two ways,the damage near wellbore by such fluids a.s drilling mud befare fracturing and taae damage behind fracture faces by fracturing fluids after fxacturing.In this paper,a general formula of well productivity ratio has been developed,taking auaunt of the variations of the formation flow capacity and the conductivity of the propped fracture in horizontal fracturing,and has been applied to analyse the practical cases with the damages mentioned above as well as those with the tail-in process.Analyses and discussions axe made an the effects of the damage bath before and after fracturing on the evaluatian of the productivity xatia.A comparison with the electric analog modeling curves gives the conditions under which the presented faxnxulas in this paper can be applied.

摘要： 地层污染包括两种情况.一是压裂前井底附近地层受泥浆等的污染;二是压裂后裂缝壁面周围地层受压裂液的污染.本文从地层系数和填砂裂缝导流能力不均匀的基本情况出发,导出了水平裂缝压裂产率比的一般计算公式.然后应用于两种地层污染和加尾砂等实际情况,讨论和分析了压裂前地层污染对产率比估价的影响和压裂后地层污染对压裂效果的影响.与前人水平缝压裂产率比电模拟实验曲线进行比较,提出了本文方法的适用范围.

关键词: 地层系数, 地层污染, 水力压裂, 产率比, 水平裂缝, 裂缝导流能力, 压裂液, 压裂效果, 计算公式, 污染程度