提高采收率开发层系组合的渗透率级差界限研究

STUDY ON THE PERMEABILITY CONTRAST BOUNDARY FOR COMBINED LAYER SERIES OF DEVELOPMENT

渗透率极差是划分和组合开发层系时需要考虑的主要因素之一,合理的渗透率极差界限可减少层间干扰,提高纵向波及系数从而使油田获得较好的开发效果。考虑生产成本与开发效果,海上油藏一般采用大井距、多层合采的方式开发,这导致生产过程中层间矛盾突出、层间干扰严重,最终影响油井的产量和油田的最终采收率。为研究开发层系组合的渗透率级差界限,采用物理模拟实验和油藏工程分析方法进行研究。结果表明,物理模拟实验和油藏工程分析方法获得的结论一致,即多层合采时各层流量比大于渗透率极差,且当渗透率极差大于7时低渗层对产量的贡献小于10%。此研究成果为未来海上油田开发层系的合理组合提供了理论依据。

Permeability contrast is one of the most important factor to combine and divide layer series of development,reasonable permeability contrast can reduce interlayer interference effectively,and improve the longitudinal sweep efficiency so that improve the oil field development effect. Considering the production cost and development effect,large well spacing and commingling production techniques were used to explore the offshore reservoirs,and this would result in interlayer contradiction problems and reduce the oilfield ultimate recovery factor. Combining with the physical simulation experiment and reservoir engineering analysis method,the relationship between permeability contrast and production ratio was obtained. The study indicated that the production ratio was higher than permeability contrast when multiple- zone production,and if the permeability contrast was higher than 7,the production percent of the lower permeability reservoir was less than 10%. The research achievements can provide reasons for the combined layer series of development in offshore oilfield.