考虑压敏效应的技术极限井距计算方法研究

传统技术极限井距计算方法未考虑特低渗透油藏压敏效应对注采井间驱替压力及启动压力梯度的影响,导致计算结果与矿场实际情况存在较大差距.针对这一实际问题,该研究通过建立考虑压敏效应油水井附近驱替压力公式及变启动压力梯度计算公式,基于传统技术极限井距计算公式,推导了考虑压敏效应的技术极限井距计算公式,并对模型进行参数分析.结果...

Study on calculation method of technical limit well spacingconsidering pressure sensitive effect

The traditional calculation method of limit well spacing does not consider the influence of pressure sensitive effect of ultra-low permeability reservoir on the displacement pressure and start-up pressure gradient between injection and production wells,resulting in a large gap between the calculation results and the actual situation of the mine.In view of this practical problem,this study has established the displacement pressure formula and variable starting pressure gradient formula near the oil-water well with pressure sensitive effect.Based on the traditional formula for calculating the technical limit well spacing,the formula for calculating the technical limit well spacing with pressure sensitive effect is derived,and the parameters of the model are analyzed.The results show that the larger the permeability,the greater the injection pressure,the smaller the bottom hole flow pressure,the smaller the pressure sensitive effect,and the smaller the technical limit well spacing.It is found for the first time that the formation pressure maintaining level has a greater impact on the technical limit well spacing.Compared with the calculation results of traditional methods,the modeling results the ultimate well spacing of type B computing technology needs to be further reduced,with an average reduction of more than 10 m.According to the calculation results in this paper,the fracturing scale of well group Y-4-W1 is optimized and effective displacement is realized.The research results can provide theoretical basis for effective development of ultra-low permeability reservoir.