Emulsion Breaker EOR for Interfacial Tension Reduction and Emulsion Control

Oscar Rojas Bermudez

Research output: ThesisMaster's Thesis

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Abstract

The driving forces controlling fluid flow in porous media during water flooding are diverse and include viscous forces, capillary forces, and gravitational forces. At the end of water flooding, the capillary force, which can be related to the residual oil saturation, Sor, is the dominant trapping mechanism. This force is the result of the fluid-fluid and rock-fluid interaction. In order to mobilize the residual oil, a significant reduction of capillary force is needed. The interfacial forces at the interface of two fluids in a porous media are directly related to capillary forces and their state of energy can be modified by natural or synthetic surface-active materials. This research project investigated the application of economical, chemically enhanced oil recovery methodologies. The target is to reduce the interfacial energy of the oil-brine systems coming from a reservoir which can be considered as special due to its interesting characteristics such as high reservoir temperature, low salinity, and importantly, the possible presence of tight emulsions. During this research fluid characterization was performed, where the produced mixture containing water in oil emulsions was classified as tight emulsions. The emulsions showed stability at temperatures up to 94 °C and to centrifugal forces, as high as 4400 m⁄s^2. Since a clear oil-water separation could not be achieved, samples containing emulsified water were used for the screening experiments. The plausibility of Alkali application (Sodium Carbonate, NaCO3) was tested under phase behavior (turbulent conditions) and dynamic interfacial tension (centrifugal force) experiments but discarded due to its limited ability to reduce the interfacial tension. The emulsion breaker solutions proved effective at reducing the interfacial tension and thereby breaking the emulsions. Droplet morphology deformations were observed during IFT measurements. Ellipsoidal and ballooning droplet shapes were observed under low and high emulsion breaker (EMB) concentrations respectively. These shapes are hypothesized o be linked to the EMB concentration of the brines and the temperature used during the experiments. The demulsifying effect improved drastically with an increase of the kinetic energy in the system (temperature), which enhanced the diffusion of the demulsifier molecules to the interfacial film of the water in oil emulsions. Core flooding experiments are needed in order to approve or discard the emulsion breaker application as an EOR agent.
Translated title of the contributionEOR-Demulgator für Grenzflächenspannungsreduktion und Emulsionskontrolle
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Knudby, Christen, Supervisor (external), External person
  • Kharrat, Riyaz, Co-Supervisor (internal)
  • Ott, Holger, Supervisor (internal)
Award date25 Oct 2019
Publication statusPublished - 2019

Bibliographical note

embargoed until null

Keywords

  • EOR
  • Enhanced Oil Recovery
  • Surfactants
  • Reservoir
  • Engineering
  • Interfacial Tension
  • Petroleum
  • Capillary
  • Emulsions
  • Phase behavior
  • Tensiometer
  • Emulsion Breaker
  • Demulsifier

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