Investigation into the application of polymers mixed with sea water for EOR in high temperature reservoirs

A three year research project involving four research institutes from Germany and Norway was initiated by DEMINEX to plan for such a polymer flood project using the Veslefrikk oilfield in the Norwegian North Sea as reference field. Chemicals must withstand temperatures of up to 120 C and be compatible with seawater and reservoir brine. New experimental technique has had to be developed and new products have had to be investigated. Seven water-base polymers were selected and their suitability for the Veslefrikk conditions investigated. The criteria upon which the selection was made were solubility in water, injectability, salt tolerance and long-term temperature stability. Only one polymer, GLUCAN WLF from WINTERSHALL, was able to satisfy all these criteria. Further laboratory work was devoted to describing the behaviour of GLUCAN WLF seawater solutions under flood conditions and estimating its adsorption characteristics in relation to the Veslefrikk reservoir rock. Results obtained were used in reservoir simulation studies. Model runs show that in the case of the Veslefrikk field, with its favourable mobility ratio, the merits of polymer flooding are expected to be an increase in vertical sweep efficiency, compared to that achieved by water flooding, due to the stratified nature of the reservoirs with correspondingly high permeability contrasts. (orig./HS)Presented at the 11. EGPC exploration and production conferenceAvailable from TIB Hannover: D.Dt.F. QN1(6,48) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman