Das Projekt "Entwicklung von Zellulosederivaten fuer den Einsatz als Viskositaetsbildner in Einpressmedien fuer eine verbesserte Oelfoerderung" wird vom Umweltbundesamt gefördert und von Wolff Cellulosics GmbH & Co. KG durchgeführt. Objective: The aim of the project is the development of cellulose derivatives that can be used as viscosifiers in flooding media in enhanced oil recovery. These novel cellulose polymers ought to be used in polymer flooding but also as a mobility control agent in micellar-polymer-processes. General Information: The project is divided into three parts. Part A: 'Modification of carboxylmethyl cellulose (CMC)' contains two phases: The improvement of the injectibility and specific viscosity of CMC insertion of a second substitutent into CMC to improve the electrolyte stability. Part B: 'Development of a new cellulose derivatives' is the main part of the project which is divided into four phases. Preparation of new cellulose derivatives by using unusual substitutions. Optimization of the processing and product properties of the new cellulose derivatives. - Insertion of a second substitutent into these new derivatives. The use of bulky substitutes as a third substitutent into new cellulose derivatives. Part C: 'Screening of the products under practical aspects' is continuously done during the whole processing of the project. Achievements: Novel cellulose derivatives with one and two substitutents were prepared and characterised in accordance with the project schedule. The product properties were investigated in distilled water and synthetic formation water. The qualifications as viscosity builders in flooding media were tested at the Bayer AG using an establishment lab program. Novel cellulose derivatives with very good properties, defined by a certain combination of substitutents, were comprehensively investigated and optimised. The properties of these types of cellulose products are: - excellent salt stability/good temperature stability; - excellent injectivity; - deoiling efficiency of 7 to 8 per cent OOIP. The deoiling efficiency of Xanthan under these conditions is between 3 and 6 per cent OOIP. The novel cellulose ethers can be prepared with standard processes of cellulose ether technology. One drawback, however, which could not be overcome as yet, is the insufficient viscosity yield compared with Xanthan. For a certain viscosity level, e.g. the concentration of the new developed cellulose products has to be 2 - 3 times higher than of Xanthan. Moreover, the structure viscosity is less pronounced for the new types.