Selection of Oil displacement Agent and performance evaluation for foam complex system

DIGEST: With the Interfacial tension test, researched the active agent interface behavior of HXJ-1 and HXJ-2.Test study indicates that the alkali concentration less than 0.6% and 1.2% respectively, the active agent HXJ-and HXJ-2 can form ultralow interfacial tension, besides the area of ultralow interfacial tension formed by HXJ-1 is larger than HXJ-2. As can be seen from the chorogram chart of foam composite index, without alkali and polymer, the two kinds of surface active agent generate the foam composite index similarly in the different density of active agent. The exist of alkali is not effect positively for the formation of super foam in the system, and adding appropriate(<200mg/L) polymer can increase the system foam effectively. When add the alkali or polymer, the area of super foam formed by HXJ-1 will larger than HXJ-2.By the percentage of foam quality, the HXJ-1 required less amount of active agent and concentration to transfer the whole system into the foam than HXJ-2, may draw a conclusion that the HXJ-1 is more easily foam than HXJ-2. The chemical flooding recovery efficiency of HXJ-1 improved three percentage point compared with HXJ-2. PREFACE With its further development of chemical flooding technique, by using flooding technology of the polymer flooding, SP flooding and alkalescent ASP flooding in the oilfield achieved good favorable and lead to make the oil recovery increased significantly([1-2]). According to statistics, there are still 40%-50% remnant oil not exploited in the oil reservoir, which indicates that it needs to apply a better way to exploit that remnant oil. Recent years, foam flooding is much accounted of as an efficient way in the tertiary oil recovery technology. Research suggests that foam has a great plugging effect, it can plug big channel but easy go through in the small channel, so it can displace the tinny channel that the high viscoelastic polymer solution can not spread to, therefore it is really an advantage for the remnant oil which isn't affected in the low permeability layer in a displacement([3,4]). This thesis aims at optimize a better active agent as foaming agent, study the foam-ability of foamable system to select the best foam system, further it can pass the test of displacement efficiency and possess the ability to improve the recovery efficiency.