低渗透油田合理井距确定方法研究——以N油田为例

针对低渗透油田合理井网密度问题,从开发技术条件与经济效益两个方面出发,考虑启动压力梯度影响,采用势的叠加原理,建立了油水两相稳定渗流时的技术极限井距模型,并推导出不同注采压差下技术极限井距与含水饱和度、含水率以及储层渗透率的关系。根据N油田采收率与水驱控制程度、井网密度的关系,考虑销售收入、开发投资的将来值、维修及管理费用等,运用曲线交会法计算出不同油价对应经济极限井网密度及经济合理井网密度。N油田目前开发阶段反九点井网210 m井距小于技术极限井距,仍有加密潜力。

Study on determination method of reasonable well spacing in low permeability oilfield

Aiming at the problem of reasonable well pattern density in low permeability oilfield,starting from technical conditions of development and economic benefits,by considering the influence of starting pressure gradient,the model of technical limit well spacing has been established by using the superposition principle of potential.The relationship between technical limited well spacing and water saturation,water content and reservoir permeability is derived under different injection production pressure.According to the relationship between oil recovery rate and water drive control,well network density,sales revenue,future value of development investment,maintenance and management costs have been considered.The curve intersection method is used to calculate the corresponding economic limit well density and economic reasonable well density.Study shows that the technical level,the current development stage of the anti nine point well 210 m well spacing in N block of Liaohe oilfield is less than the technical limited well spacing,and it still has the potential for encryption.In terms of economic efficiency,the oil field well density is less than the economic reasonable well density,and the well network adjustment space is very large.The research results are of significance for guiding the rational well spacing in low permeability oilfield.