摘要
为更好地认识压裂充填井渗流规律,有效评价压裂效果,依据物理模型三个区域的渗流过程,建立三区复合油藏数学模型,求出各个区域的压力解,沿着裂缝方向对连续点源进行叠加积分,结合Duhamel原理,得出考虑井储效应和表皮效应的压裂充填井Laplace空间无因次井底压力解,通过Stehfest数值反演绘制无因次压力及导数特征曲线,并对特征曲线进行流动阶段划分和影响因素分析。分析表明,压力特征曲线依次表现为井筒储集阶段、过渡阶段,裂缝系统与地层的双线性流阶段、地层线性流阶段、径向复合特征以及后期的边界反映;裂缝表皮系数主要影响过渡段,表皮系数越大,压力导数的驼峰值越高;裂缝穿透Ⅰ区、Ⅱ区导压系数比越小,压力及压力导数曲线位置越靠下;裂缝穿透Ⅰ区、Ⅲ区导压系数比越小,越早呈现径向复合特征,径向流位置越靠下。该方法提高了对压裂充填井渗流规律的认识,为压裂充填技术试井解释提供理论支持。
To better understand the seepage law of fracpack wells and effectively evaluate the fracturing effect,based on the seepage process in three zones of the established physical model,a mathematical model of the three-zone composite reservoir was established.The pressure of each zone is obtained..Through the superposition integral of the continuous point source along the fracture and combining with the Duhamel principle,the Laplace space dimensionless downhole pressure solution of the fracpack well considering the well storage effect and the skin effect is obtained.The dimensionless pressure and derivative curves are drawn by Stehfest numerical inversion.After that,the flow stage is divided and influencing factors is analyzed for the characteristic curve.The analysis shows that the pressure curve has the stages of the wellbore storage stage,the transition stage,the bilinear flow stage of the fracture system and the matrix,the linear flow stage of the formation,the radial composite feature and the later boundary response.The fracture skin factor mainly affects the transition stage and larger skin coefficient results in higher hump peak of the pressure derivative.The smaller the pressure conductivity coefficient ratioω-21,the lower the pressure and pressure derivative curve are.Smallerω-31 leads to the earlier radial composite feature and the lower radial flow curve.This method improves the understanding of the seepage law of fracpack wells and could provide theoretical support for the well testing interpretation of fracpack well.
作者
高杰
冯青
黄子俊
杨浩
王艳红
杨慰兴
GAO Jie;FENG Qing;HUANG Zijun;YANG Hao;WANG Yanhong;YANG Weixing(Oilfield Production Research Institute of China Oilfield Service Co.,Ltd.Tianjin 300459,China)
出处
《油气井测试》
2018年第6期8-13,共6页
Well Testing
关键词
压裂充填井
试井
复合油藏
渗流模型
压力特征曲线
敏感性分析
fracpack well
well test
composite reservoir
seepage model
pressure characteristic curve
sensitivity analysis
