【作者】 高建；

【导师】 廖新维；

【作者基本信息】 中国石油大学(北京) ， 油气田开发工程， 2018， 硕士

【摘要】 致密气藏普遍孔隙度和渗透率较低,并具有应力敏感特性,属于非常规气藏。在苏里格气田某些产气井试井测试曲线中,曲线尾部出现了下降的特征,以常规试井解释方法得不到合理的解释结果。本文基于致密气藏储层特征、压裂井渗流模型及补给边界表征模型等国内外文献的广泛调研,建立了针对致密气藏补给边界的表征模型,厘清了各参量含义,建立了补给边界点源函数。考虑补给边界条件和人工裂缝分别为无限导流和有限导流,建立了应力敏感储层压裂井模型,引入摄动变换式处理强非线性,考虑井筒存储系数和表皮系数进行数值反演。获取了考虑补给边界条件下致密气藏压裂井的井底压力响应曲线,分析了响应特征和渗流动态,分析结果表明井筒存储效应和表皮效应会掩盖早期流动阶段,应力敏感效应使曲线中后期产生上翘;补给边界特征将产生隆起,补给强度影响峰顶出现的时间和高度,而补给压力仅影响隆起峰顶的高度。基于特征点法建立了补给边界压裂井试井解释方法,得到了各流动阶段参数表达式,根据补给压力和补给强度的影响特征确定补给边界参数。在实例应用中,采用了补给边界试井模型拟合了异常的实测试井曲线,解释了异常的边界响应特征,验证了致密气藏补给边界压裂井试井模型的适用性。更多还原

【Abstract】 Tight gas reservoir with low porosity and low permeability and serious stress sensibility is unconventional gas reservoir.Well testing curve of some gas wells in Sulige gas field,the tail of which appear downward trend,can’t be reasonably explained by conventional and modern method.In this paper,the extensive research was investigated based on tight gas reservoir,fractured well model and recharge boundary.A representation model of recharge boundary suited to tight gas reservoir is established and parameters are figured out,and source functions of recharge boundary was established.Well test model of fractured well based on recharge boundary and stress-sensitive effect in tight gas reservoir was established,the flow conductivity of whose fracture is infinite and finite.Strong nonlinear is solved on use of perturbation transformation method.The advantage of superposition theorem introduces wellbore storage coefficient and skin factor in Laplace space.Curves of well test model based on recharge boundary in tight gas reservoir are drew,their characters are analyzed,and flow stages are divided.Wellbore storage and skin effect covers up early-stage.Stress-sensitive effect leads to curves rising in middle and later stages.Characters of recharge boundary are heave curve,and its strength impacts on the peak and its appropriate time,and its pressure impacts on the peak only.Based on feature points method,it’s proposed to interpreting methods of well test in tight gas reservoir with recharge boundary.Calculation formula of feature points in flow stages is given,and we can determine parameters of recharge boundary.In the sample application,the model with recharge boundary fitted abnormal well testing curve,and explained boundary characteristic,and applicability of fractured well test model based on recharge boundary in tight gas reservoir was proved.更多还原