Adsorção estática do polímero FLOPAAM em rocha arenítica

Abstract

When the energy from the reservoir rock isn’t enough to produce petroleum in a naturally way or when there is a production decline in depleted reservoirs, it’s necessary to use processes that have the function of intervening in the reservoir, these so-called supplementary petroleum recovery, being conventional or special. It’s the case of the polymer solution injection in the injection well, a special supplementary recovery method that involves chemical processes in order to change the water viscosity and, consequently, improving the petroleum flow towards the producing well. Polymer solutions may be subjected to the retention mechanisms such as polymer adsorption where there is a physical or chemical interaction between the surface of the solid (rock) and the polymer molecules. With this interaction, the polymer of the injected solution sticks to the rock surface, reducing its concentration in the solution, as well as the viscosity of the shifting fluid. Adsorption of the partially hydrolyzed polyacrylamide polymer (HPAM) on the rock surface was studied through static adsorption experiments (finite bath). By analyzing the results obtained according to the Langmuir and Freundlich isotherms and comparing them, it’s possible to state that the Freundlich model was more favorable to adsorption, signaling a multilayer process, where the value of its constant, n, was 2,1295, being within the range of 1 to 10. The graphical relationship between adsorption and equilibrium concentration constructed with the results obtained showed that polymer adsorption occurred unfavorably, an expected result since the polymer used FLOPAAM 3330 S is commercially available and used in the field for non-adsorption.