Study On Gelled Foam System For Profiling And Flooding

Gelled foam,formed by gel foam agent, crosslinking agent and polymer solution underthe condition of gas , has the characteristics of foam and gel , and it can also overcome theshortcomings of the both former. In this paper, the formula of the gelled foam system isdetermined through experiments, and factors are examined, including components, pH, salt,oil and temperature, ect. And the applicable conditions of the system are put forward. Effectsof gas liquid ratio, permeability and oil concentration on gelled foam's sealing properties areinvestigated, and the result is that oil saturation is the most important aspect. That's to say,when oil saturation increases, gelled foam's sealing capacity declines. Hence, layers of largepermeability and high water saturation, have priority to being sealed by gelled foam system.Single core and parallel core profile control experiments showes that gelled foam can wellcontrol the flow value and invalid displacement which helps to improve the swept volume.Inaddition, three main generation mechanisms leave behind, neck snap off and fluid filmdivision are drawn from the micro phenomenon of gelled foam generating and flowing inporous medium through visual physical model. Gelled foam enhances oil recoery mainly byextruding and occupying, selectively blocking large channels and impacts of shearing andcarrying. Finally, gelled foam profile control experiments of W354038 well in xiaowa ofLiaohe oilfield reveals that the effect is good with increased oil output up to 300 tons, anddecreased water content up to 30%, which represents the integration of compiling andcontroling.