【作者】 王晖；

【导师】 姚军；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2010， 硕士

【摘要】 压裂是开发低渗油藏的有效措施,已在油田现场广泛应用。低渗油藏压裂后形成垂直裂缝和水平裂缝,因此需要充分认识压裂后裂缝对油藏渗流的影响,再结合试井资料正确了解地层性质。本文应用Green函数方法和Newman乘积方法,建立了垂直裂缝压裂井垂直裂缝在无限大油藏、封闭边界油藏、定压边界油藏三种情形下的试井解释理论模型,每种情形下又分为不考虑裂缝开度和考虑裂缝开度两种情形,并求得了井底压力的解析解,绘制了压力和压力导数的双对数曲线,分析了裂缝开度、对称性、油藏和裂缝尺度等的影响;其次本文还应用上述方法建立了垂直井水平裂缝试井解释理论模型,同样分为不考虑裂缝开度和考虑裂缝开度两种情形,得到井底压力解析解,绘制了压力和压力导数的双对数曲线,研究发现由于水平裂缝开度很小,对井底压力影响可以忽略不计,但水平裂缝在垂向上的位置对井底压力影响较大,必须予以考虑。最后建立了考虑启动压力梯度的低渗油藏数学模型,通过Laplace变换得到拉氏空间下井底压力的解,通过数值反演得到了井底压力的数值解,发现启动压力梯度的存在使渗流偏离达西渗流,且启动压力梯度越大,偏离线性渗流的时间越早,偏离幅度越大;另外还分析了裂缝导流能力、水力扩散系数、井筒存储和表皮系数等参数的影响。更多还原

【Abstract】 Fracturing is the effective measures for development of low permeability which have been widely used in the oil field. After fracturing in low permeability reservoir vertical fractures and horizontal fractures formed,it is necessary to fully understand the impact of fractures on reservoir flow,and then combined with well testing data we can fully understand the nature of the reservior. In this paper,the Green function method and Newman product method are used to build the vertical fracture welltesting models in the infinite reservoir,closed boundary reservoir,constant pressure outer boundary reservoir,each case is divided into two cases,considering fracture aperture and without considering fracture aperture,the analytic solutions of bottom pressure is obtained and drawing the pressure and pressure derivative log-log type curves,analyse the influences of the fracture aperture,fracture symmetry and reservoir and fracture scale; Using the same method the horizontal fracture model in vertical well is built and obtain the analytic solution,drawing its pressure and pressure derivative log-log type curves,generally the horizontal fracture aperture is very small and its influence can be ignored,but the vertical position of horizontal fracture in the reservoir should be taken into consideration. Finally considering the actuating pressure gradient,the flow model for low permeability reservoir are built,the numerical solution of bottom-hole pressure is derived,it is found that the flow deviates from the Darcy flow because of the presence of actuating pressure gradient ,and the greater the actuating pressure gradient is ,the earlier the flow deviates from the linear flow and the greater deviation; analyse the influemces of fracture conductivity,hydraulic diffusivity,wellbore storage and wellbore storage for bottom hole pressure.更多还原