摘要
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。结果表明,渗透率越大,注入压力越大,地层压力保持水平越高,采油井井底流压越小,压敏效应影响越小,启动压力梯度越小,技术极限井距越小。与传统方法计算结果相比,所建模型计算技术极限井距需要进一步缩小,平均缩小10 m以上;Y-4-W1井组根据文中计算结果优化设计压裂规模后,实现了有效驱替。该研究成果可为特低渗透油藏有效开发提供理论基础。
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.
作者
李承龙
LI Chenglong(Exploration and Development Research Instiute,Daqing Oilfield Company Ltd.,Heilongjiang Daqing 163712,China;Heilongjiang Key Laboratory of Reservoir Physics and Percolation Mechanics,Heilongjiang Daqing 163712,China)
出处
《非常规油气》
2021年第2期56-61,126,共7页
Unconventional Oil & Gas
基金
国家科技重大专项“外围油田改善开发效果及提高采收率技术研究与应用”(2016E-0209)。
关键词
特低渗透油藏
压敏效应
变启动压力梯度
技术极限井距
extra-low permeability reservoir
pressure sensitive effect
variable starting pressure gradient
technical limit well spacing
作者简介
李承龙(1986—),男,博士,工程师,主要从事油田开发调整、提高采收率等方面的研究工作。E-mail:lcl716@126.com。
