This paper discusses the applications of gas and water tracers in the Central Fault Block (CFB) of the Snorre Field in the North Sea. An extensive tracer program was initiated in 1993 to improve the understanding of the flow dynamics in the field. The CFB of Snorre has been produced by WAG injection since 1994. The tracer program has involved 3 injectors and 4 producers. Tracers applied were perfluorinated hydrocarbons (PFCs) and SF6 as gas tracers. As water tracers tritiated water (HTO), chemical SCN- and radioactive S14CN- have been applied in addition to the new tracer 4-fluoro benzoic acid (4-FBA). Results from this integrated tracer study have improved the understanding of fluid flow and WAG injection efficiency in the reservoir. The tracer program will be continued and will also be expanded to other fault blocks.

No abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper presents the application of water tracer flow simulations as a means for better characterization of the Central Fault Block (CFB) reservoir in the Snorre field in North Sea. The simulations of the tracer flow were carried out using a numerical model, developed by the Institute for Energy Technology for modeling of tracer flow in porous media, coupled to CMG-STARS chemical/thermal simulator. The tracer data was first analyzed to establish reservoir continuity between three injectors and six producers in the fault block. Then, tracer flow simulation results were matched with measured tracer field data in order to improve the history match of the water cut in the reservoir model.History matching of tracer production profiles is presented together with history matching of water cut before and after the consideration of tracers to highlight the improvement of the reservoir model.

No abstract