Surfactant / Hydrophobically Associating Polymer Binary System Flow Degeneration Study

The problems after ASP compound flooding that alkali reduces viscoelasticity of polymer solution making sweep efficiency and displacement efficiency reduced, also reduces the permeability, and alkali incrustation is formed. So polymer/surfactant flooding gradually became a new emphases of research on oil recovery technologies. The binary system with no-alkali of ultralow interfacial tension and high viscosity became a key to binary flooding technologies. Depth and systematic understanding of various kinds binary system rheological properties,including the rheological properties and displacement characteristics of the polymer/surfactant interaction and different construction of polymer and surfactant and compound mode of polymer/surfactant will contribute to a correct understanding and application of the binary displacement system,also will contribute to the design/selection the molecular structure of polymer and surfactant,is the basis of the study of binary systems.Aim at those questions, this essay systematically study the rheological of binary systems with the variation of composition, including different kinds of surfactant (incluing several novel molecular structure surfactant of laboratory-made,compound of anionic/non-ionic surfactant and the molecular structure of polymer (including different content of hydrophobic and different length of hydrophobic).Study found that SDBS and OP-10 and multi-polarity surfactant BH interaction with hydrophobically associating water-soluble polymer(HAWSP),the changing trend of viscosity consistent with "three-phase model",SDBS can increase the viscosity in wider range of concentrations,and highest viscosifying, BH is second and OP-10 is least. Additionally, study found that the viscosity of binary systems increases with the FNR concentration in 0-3000mg/L,and viscosifying is much higher than the other surfactant. Analysis consider most common non-ionic surfactants are ethoxylates,their huge hydrophilic will obstruct the interaction between surfactant and HAWSP, different from those surfactant, complex FNR molecules may contain some groups of more easily interaction with associating polymer.The same time, binary systems has higher viscosity in wider range of FNR concentrations. When added OP-10 to the binary system of SDBS/HAWSP and BH-2/HAWSP, the viscosifying and increasing viscosity interval of composite system are reduced.It shows that OP-10 obstruct SDBS and BH interaction with HAWSP.When add little FNR to complex solution, the system Viscosity increases sharply, once again proved FNR have good viscosifying.Study found that self-made multi-polarity surfactants of sulfonate BH series, with the alkyl chain length of the molecule increased, the increasing viscosity interval and viscosifing all increased. Also found that, with the increase of hydrophobic group content and hydrophobic length of HAWSP in a certain range, the increasing viscosity interval and viscosifing still increased, but more than a certain value, the viscosify of the binary system decreased.By measuring some elastic parameters,such as G'/G", N1, R, etc., when the binary system with the same viscosity, the flexibility of system increases as the surfactant concentration increasing; With the increasing of multi-polarity surfactant's alkyl chain length, the system's flexibility has also increased; With the increasing of hydrophobic groups content, the system's flexibility is still increasing; Hydrophobic length increases within a certain range also helpes to increase system's flexibility.The study showed that,On the one hand, SDBS,BH-2 and FNR increase in a certain range of concentration will help improve the viscosity of binary system, the hydrophobic group content and hydrophobic length of HAWSP increase in a range also favored improving of the viscosity; On the other hand, the length of alkyl chain in multi-polar surfactant, favored increasing of the flexibility of system, increasing of the content of hydrophobic groups and appropriate hydrophobic length also greatly enhance the system's flexibility. Therefore, take as much as possible favorable factors when selectes binary system formulations, also need to consider the interfacial activity, in order to obtain better integrated nature of the binary flooding.