Phase Behavior of Alkaline Surfactant Polymer in Hard Water

The needs and increasing price of the oil time by time has become the motivation to
have more research on the oil recovery in this recent day such as Alkaline Surfactant
Polymer (ASP) which is categorized as tertiary recovery or enhanced oil recovery
(EOR). The ASP flooding was developed in the early 1980’s as a lower-cost alternative
to micellar/surfactant polymer flooding.
The process of this flooding consists of injecting a slug mixture of alkali-surfactantpolymer,
followed by the injection of additional polymer and then chase water. The
combination of these three chemicals in the slug is more effective than injection of
individual components. Despite the effectiveness of combining these three chemicals,
the ASP flooding will form precipitation as a reaction to the formation water which has
high content of divalent ions such as ferum and magnesium in offshore formation water
(hard water) compared to the onshore formation water.
The precipitation formed will reduce the permeability thus decrease the production.
Hence, in order to prevent the form of precipitation or scale, an optimum concentration
of ASP and salinity of the hard water will be studied experimentally. The experiment
will be conducted by varying the salinity of hard water also the concentration of the
alkali, surfactant and polymer to identify the formulation that will gives no precipitation
and the Winsor Type III microemulsion. This optimum ASP formulation will give
higher oil recovery as the reaction of alkali and acid in the crude oil will create in-situ
surfactant which will reduce the interfacial tension (IFT) and polymer will act as
thickening agent to improve the sweep efficiency.