油气地质与采收率2025，Vol.32Issue(6)：137-145,9.DOI:10.13673/j.pgre.202508033
裂缝性特低渗透砂岩油藏控速增渗注水提高采收率技术及应用
Technology and application of controlling injection rate and increasing imbibition effect to enhance oil recovery in fractured sandstone reservoirs with ultra-low permeability:A case study of Ordos Basin
王香增 1王小锋 2梁全胜 2党海龙 2侯玢池 2崔鹏兴 2高涛2
作者信息
- 1. 陕西延长石油(集团)有限责任公司,陕西 西安 710065
- 2. 陕西延长石油(集团)有限责任公司 研究院,陕西 西安 710065
- 折叠
摘要
Abstract
The pore-throat of the fractured sandstone reservoir matrix with ultra-low permeability is fine,and micro fractures are developed,which provides favorable conditions for the role of imbibition and oil displacement;surfactant solution can change the interface reaction between rock and fluid,enhance imbibition effect,and have an important impact on enhanced oil recovery.Through interface tension experiments,wettability determinations,and spontaneous imbibition experiments,the interface tension,wettability,and spontaneous imbibition and oil displacement efficiency of the anionic non-ionic surfactant YCSX-1 solution with different mass fractions were studied,as well as the influence of the injection mass fraction and injection rate of the surfactant on the oil displacement efficiency.A matrix-fracture dual-medium core was innovatively designed based on the Warren-Root model,and a dual-medium mathematical model considering the effects of surfactants and imbibition was constructed.Physical and numerical simulation methods were comprehensively employed to investigate the oil displacement laws under different injection mass fractions and injection volumes of surfactants.The experimental results demonstrate that the interfacial tension and wetting contact angle decrease first and then increase with the increase in surfactant mass fraction,which are the key factors affecting the imbibition's oil displacement efficiency.The surfactant system with a mass fraction of 0.4%has the strongest imbibition effect and the highest oil displacement efficiency,and the enhanced imbibition effect improves the mobilization of crude oil in the matrix.The oil displacement efficiency shows a trend of increasing first and then decreasing with the increase in injection rate.The optimal injection rate is 1.2 mL/min.Based on the experimental results,the constructed dual-medium mathematical model was used for simulation calculation,and the injection parameters were optimized.The optimal injection mass fraction is 0.4%,and the optimal single-well injection volume is 12 m3/d.The simulation result was applied to the water injection development in the X Block,yielding an obvious effect,and the maximum increase in daily oil production is up to 54%.The technology of controlling injection rate and increasing imbibition effect to enhanced oil recovery changes the interfacial tension and wettability of matrix pores through the mass fraction optimization of surfactant solution;it simultaneously controls the water injection rate to ensure that the meniscus of the two-phase fluid remains in an ideal dynamic state during the oil displacement process,exerting the dual dynamic effects of capillary force and displacement pressure,further enhancing the relative contribution of flow and absorption in the oil displacement process,and increasing the flow capacity of crude oil in the small-pores of matrix.More crude oil in the pores of the matrix is recovered,improving the oil displacement efficiency.关键词
特低渗透砂岩/表面活性剂/基质-裂缝岩心/注入速度/驱油效率/提高采收率Key words
ultra-low permeability sandstone/surfactant/matrix-fracture core/injection rate/oil displacement efficiency/enhanced oil recovery分类
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王香增,王小锋,梁全胜,党海龙,侯玢池,崔鹏兴,高涛..裂缝性特低渗透砂岩油藏控速增渗注水提高采收率技术及应用[J].油气地质与采收率,2025,32(6):137-145,9.
