Objectif The project consists in developing a set of thermodynamic models to provide a really reliable restitution of the PVT laboratory experiments, and hence give a better simulation of injections in a reservoir model, particularly as regards miscible gas. This is essential to optimize the implementation of a pilot phase in a project, which can be extremely expensive, especially in the North Sea(e.g. ALWYN).Phase 1 : the methodology apparatus for determining the measurement of pressure, volume, temperature, has been built and is widely used. It was proven on CO2-isobutane mixtures. The CO2 n-octane studies have been completed, and the CO2-eicosane studies are underway, plus research on the dew point, for strict methods, is underway (dew point detection by image analysis, luminous intensity).Phase 2 : during the development of the parameter adjustement method, the algorithms for calculating the liquid-vapor equilibrium have been made thouroughly reliable; an algorithm for calculating three-phase equilibria (L1-L2-G) has been developed to allow the simulation of CO2 injection into shallow reservoirs. An industrial version will be available in October 1987.This project consists of two phase :PHASE 1 - MEASUREMENTS AND ANALYSESThe thermodynamic model at present available, requires data on the critical properties of the components and the interaction coefficients between the heaviest specific cuts and the lightest components. An apparatus has been developed in order to determine the interaction coefficients between the heavy components and the CO2, by experimental determination of the phase envelopes under given pressures and temperatures.The heavy cut is represented by a pseudocomponent to which are attributed critical properties, based on experimental data, such as density, molecular weight, boiling point. The NMR determination of a typical average molecule, makes it possible to know the molecular weight of the mixture with greater accuracy, and the use of group contributions in the models, allowing a better representation of this type of components.PHASE 2 - MODELLING STUDYThe most commonly used models are derived from Van derWaals' equation (the best known is that of Peng-Robinson). The adjustment of the parameters (Tc, Pc, W, kij) of the pseudocomponent(s), which was almost manual, has been systematized, determining from all the data contained in the PVT laboratory reports, the properties of the heaviest pseudocomponent. The method uses the principle of maximum probability, and integrates the experimental errors through variance and covariance matrices. Other representations of heavy components, such as that by group contributions, or continuous distributions, are being studied. With group contributions, the properties of the cuts will be determined, and in particular, the interaction coefficients can be calculated. In a first phase, the continuous distributions will be used to make the best choice of the number of pseudocomponents representing the heaviest cut, and to determine their characterisitics. Programme(s) ENG-HYDROCARB 1C - Programme (EEC) of Community projects in the hydrocarbons sector, 1973-1985 Thème(s) 1.5 - IMPROVED OIL RECOVERY Appel à propositions Data not available Régime de financement DEM - Demonstration contracts Coordinateur GERTH Contribution de l’UE Aucune donnée Adresse 232 AV. NAPOLEON BONAPARTE 92500 Rueil Malmaison France Voir sur la carte Coût total Aucune donnée
