低渗透气藏压裂井产能研究

【作者】 岳建伟；

【导师】 段永刚；

【作者基本信息】 西南石油学院 ， 油气田开发工程， 2004， 硕士

【摘要】 在已发现的天然气藏中,属于中、低渗透,甚至特低渗透的储集层,占了相当大比例,具有广阔的开发前景。由于水力压裂是对这类气藏进行开发和增产的一种有效手段,因此,本文以油气渗流理论为基础,以压裂气井为研究对象,以压裂气井产能为研究目标,对压裂气井的渗流模型、产能预测模型以及产能影响因素进行讨论,开展了以下研究工作。 (1) 通过对有限导流垂直压裂井的渗流数学模型进行求解,得到了裂缝线性流、双线性流、地层线性流以及拟径向流四个阶段的井底压力解,并对各阶段的流动特征进行了分析,作出了考虑井筒储集系数和裂缝污染系数的井底压力图版。 (2) 依据有限导流垂直压裂井的渗流数学模型求得的井底压力解,通过数学变换,得到了有限导流垂直压裂井的二项式瞬态产能预测模型。 (3) 将裂缝平分为多个微元段,运用格林函数及线源函数,推导了无限导流垂直压裂井模型的微元段流量分布与无因次裂缝距离关系方程,从而得到了裂缝微元段的无因次流量分布方程组,根据方程组的求解结果,得出了无限垂导流垂直压裂井模型的井底压力解。 (4) 根据无限导流垂直压裂井模型的井底压力解,结合回压试井的原理,得到了改进的等时试井的压降和压恢通式,进一步得到了它的二项式产能预测模型。 (5) 根据上面提出的压裂井产能预测通式,用气田实例进行了产能预测模型的验证,选择了产能预测模型,并对产能影响因素进行了分析。 通过本文的研究,得到了压裂气井的产能预测模型,并提出了模型的选择对比方法,从而为压裂后的产能评价,以及压裂井的优化设计提供了可靠的理论基础。更多还原

【Abstract】 The gas reservoirs, which have been found middle-low or very low, are in the majority, Exploiting them has capacious foreground. Because hydraulically fracturing is an effective measure of the gas reservoirs exploited and productivity increased, this paper is based on oil and gas seeping theory, by a research object of gas well fractured, by a research target of gas well productivity fractured, which studied the seeping model, productivity forecast model and productivity influence factors of gas well fractured.(1) By the Finite-conductivity Vertically Fractured Well Model solved, we gained four of the fracture linearity flow solution, the bilinear flow solution, the formation linearity flow solution and the pseudo-radial flow solution. The character of every flow phase is analyzed. And the well-bottom pressure graphic tablets involved in the effect of wellbore storage and fracture damage have been plotted.(2) According to the well-bottom pressure solution of Finite-conductivity Vertical Fractured Well Math Model, which is transformed in Mathematics , the Binomial Ephemera Productivity Forecast Model was derived.(3) After fracture is plotted out into many puny parts on average, flux distributing equation of puny parts of Infinite-conductivity Vertical Fractured Well Model, which is related with dimensionless distance, is derived by Green Function and Line-source Function. So dimensionless flux distributing equation group of puny fracture parts is gained. By the solution of the group, the well-bottom pressure solution of Infinite-conductivity Vertical Fractured Well Model is derived, which is combined with Uniform Flux Horizontal Fracture Model.(4) By the well-bottom pressure solution of Infinite-conductivity Vertical Fractured Well Model, which is combined with the Back Pressure Well Test principle, the generic formulas of the pressure-down and pressure-back of isochronous Improved Well Test are derived. Fartherly, the form of Binomial Ephemera Productivity Equation is derived.(5) As the result of the formulas put forward of productivity forecast model. The productivity forecast models are validated by the actual example of gas field. So The productivity forecast models is chosen. And the influence factors of productivity are analyzed.Through the research of this paper, the productivity forecast models are gained. And the choice methods of the model are put forward, so for the economicappraise and optimize design of fracture, a dependable theory base is offered.更多还原