Experimental study and application of air foam flooding system in high salinity tight reservoir
Aiming at the problem of unstable performance of conventional foam flooding system in gas flooding process of tight oil reservoir with high salinity medium and unable to effectively displace crude oil,laboratory evalu-ation experiments were conducted on 4 kinds of foaming agents and 2 kinds of foam stabilizing agents,and a gas flooding foam system suitable for high salinity medium was selected and combined.The foaming and bubble stabilization performance and field recovery efficiency of the compound system were evaluated under the condition of indoor high salinity medium.The results showed that under the same concentration of foaming agent,the foaming volume and half-life of foaming agent HK559 were much higher than those of the other three foaming agents.The optimal concentration of foaming agent HK559 was 0.25%,and the optimal volume ratio of foaming agent HK558 was 5∶5.Compared with other foams,the 5∶5 composite system of HK559 and HK558 had the characteristics of strong Ca2+resistance,good foam stability,oil resistance and stability,which was the best choice for air foam displacement system in high salinity tight reservoirs.After the HK series 5∶5 compound system was adopted for air foam flooding in 4 injection&production well groups in Block L,the daily oil production per well increased by 91.89%,the average oil of 4 well groups increased by 5.28 t/d,the average water cut decreased by 6.4%,and the oil increased by precipitation was significant.This study can provide reference for the efficient and reasonable development of similar tight reservoirs.
high salinitytight oil reservoirair foam displacementperformance evaluation
NETL
NSTL
万方数据
