The Interaction and Rheological Behavior of Preformed Gel Particles with Surfactants

Heterogeneous combination flooding systems are composed of surfactant and viscoelastic preformed gel particles (PGP) that can migrate in the pores. The interactions between PGP and surfactants have an important impact on the system. In our research described here heterogeneous aqueous suspensions of PGP and an anionic surfactant (sodium dodecyl benzene sulfonate, SDBS) or a nonionic surfactant coconut oil alkanolamide, (CDEA) were prepared. The effects of SDBS and CDEA on the swelling and rheological properties of the PGP was investigated. In addition, the influence of SDBS and CDEA on the thermal effects of PGP was studied. The results showed that the swelling ratio, apparent viscosity and storage modulus of the PGP decreased with the increase of SDBS concentration. On the contrary, the CDEA increased the swelling ratio and the rheological properties of PGP. The specific heat capacity (Cp) of PGP increased with the SDBS concentration and decreased with the CDEA concentration. Similar to the rheological behavior, the influence of interactions on the PGP molecular thermal motion was related to the concentration of the surfactants. Therefore, studying the variation of Cp with concentration can provide reference for the reasonable dosage of surfactants in heterogeneous oil displacement systems and a new perspective for investigating the interaction between surfactant and PGP or other polymers.