Thin-film spreading agent

TFSA molecules have been extensively and successfully used as steam additives in cyclic steam operations(27-32). Recently, results of a TFSA-waterflood which was conducted in West Texas were reported(33). The purpose of the work described in this paper was to further evaluate the feasibility of recovering incremental oil in a mature waterflood by injection of surfactants which change the wettability of reservoir rock surfaces. In this paper, we present the results of laboratory studies with Thin Film Spreading Agents and the results of a carefully conducted TFSA-waterflood pilot in the Torrance Field located in the Los Angeles Basin of California. 

DEMULSIFICATION TESTS. Demulsification tests were conducted using standard bottle test procedures to evaluate the relative performance of Thin Film Spreading Agents in coalescing emulsions of formation brine in crude oil under reservoir conditions. 

Table I. Recovery of Oil from Oil-Wet Sand Increases As Concentration of Thin Film Spreading Agent Increases...

Oil recoveries after the oil-wet sand was contacted with equal volumes of brine containing the reported concentrations of Thin Film Spreading Agents. 

Table II. Thin Film Spreading Agents Make Asphaltene-Modified Surfaces More Strongly Water-Wet...

Alkoxylated phenol formaldehyde resins are a well-known class of demulsifier, and the emulsion coalescence data in Table III confirm that Thin Film Spreading Agents, which belong to this class, can also function as chemical demulsifiers. When water in... 

Table III. Thin Film Spreading Agents Are a Well-Known Class of Chemical Demulsifier...

Thin Film Spreading Agents are synthetic surfactants which change the wettability of reservoir rock surfaces from oil-wet and intermediate wettability to water-wet. 

Since Thin Film Spreading Agents do not produce ultralow interfacial tensions, capillary forces can trap oil in pore bodies even though the oil has been displaced from the surface of the porous medium. Therefore, recovery of incremental oil is dependent on the formation of an oil bank. Muggee, F. D. U.S. Patent 3 396 792, 1968. 

LB multilayer thin films can also be formed from nickel-tetra-tert-butyl-phthalocyanine, iron-tetra-tert-butylphthalocyanine, and mixtures of these phthalocyanines with PHT. The phthalocyanine molecules serve as both a surface active agent to promote spreading and an electroactive material [424,425]. 

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