摘要
低渗透油藏开发到高含水期阶段,钻加密井和调整井距是挖潜剩余油、提高原油采收率的重要措施。技术极限井距是挖潜剩余油的一个重要指标。针对低渗透油藏存在启动压力梯度的特征,以油水两相稳定渗流理论为基础,通过引入视粘度和拟势的概念,采用势的叠加原理推导建立了低渗透油藏技术极限井距计算公式,并以实际油藏参数为例,分析了储层渗透率、含水饱和度和注采压差等技术极限井距的影响因素。结果表明,技术极限井距随着储层渗透率、含水饱和度和注采压差的增加而增大。将计算结果应用到实际油藏井网部署中,储层物性较好、剩余油饱和度较低的区域,技术极限井距最大约为350 m;储层物性较差、剩余油饱和度较高的区域,技术极限井距最小约为250 m。调整后的井网对剩余可采储量的控制能力增强,预测提高采收率4.1%。
When the development of low permeability reservoir reaches the high water-cut stage,infill well or well spacingadjustment is needed to exploit the remaining oil and enhance the oil recovery efficiency. The technical limited well spac-ing is an important factor of tapping the potential of the remaining oil. Based on the feature of start-up pressure gradient inthe low permeability reservoir and the theory of the oil-water two-phase flow,concepts of pseudo-viscosity and pseudo-po-tential were introduced. A calculation formula of the technical limited well spacing in the low permeability reservoir was es-tablished based on the potential superposition principle. The influencing factors such as the reservoir permeability,watersaturation and the inject-production pressure difference were analyzed with the actual reservoir parameters. The resultsshow that the technical limited well spacing increases with the reservoir permeability,water saturation and the inject-pro-duction pressure difference. The calculation results were applied into the actual well pattern arrangement. The maximumwell spacing is about 350 m in the areas with better physical properties and low remaining oil saturation and the minimumone is about 250 m in the areas with poor physical properties and high remaining oil saturation. Adjusted well pattern hasstronger control ability on remaining recoverable reserves and the oil recovery efficiency will be enhanced by 4.1 percent.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2015年第2期88-92,共5页
Petroleum Geology and Recovery Efficiency
基金
国家科技重大专项"胜利油田薄互层低渗透油田开发示范工程"(2011ZX05051)
关键词
低渗透油藏高含水期拟势
叠加原理
技术极限井距提
高采收率
low permeability reservoir
high water cut stage
pseudo potential
potential superposition principle
technicallimited well spacing
enhanced oil recovery
