Pétrole, gaz, environnement : quelle approche de la R&D en exploration-production pour la fin du siècle ?

Oil, Gas and the Environment: What Approach by R&D in Exploration-Production for the End of the Century?

Institut Français du Pétrole

Résumé

Cet article rappelle tout d'abord, un constat du XVe Congrès du Conseil Mondial de l'Énergie (Madrid, septembre 1992) : au cours des 30 prochaines années, les énergies fossiles vont continuer à être à la base de tout approvisionnement énergétique . Examinant les conditions de ce maintien dans un contexte géopolitique difficile, il montre qu'une des voies à privilégier est d'accroître les efforts de recherches pour réaliser les progrès scientifiques et technologiques qui permettront de satisfaire la demande en pétrole et en gaz pour le début du 21ème siècle. L'effort de R & D nécessaire pour disposer des technologies pétrolières et gazières de la prochaine décennie nécessite une recherche faite en commun, car seule une recherche coordonnée évitera une dispersion des efforts français. L'élargissement des réserves économiquement exploitables, la maîtrise du coût de production et la réduction des coûts des chaînes gaz des champs de production aux régions consommatrices, tout en assurant la protection de l'environnement sont les prochains défis à relever. Pour faire face à ces attentes de l'industrie, d'importants efforts de recherche doivent être menés dans les domaines scientifiques correspondants, afin de mieux appréhender les phénomènes et de développer les solutions les plus appropriées. En définitive, les progrès scientifiques et technologiques, nécessaires à l'élargissement des réserves économiques exploitables, à une plus grande accessibilité aux ressources pétrolières et gazières, ainsi qu'à une utilisation mieux ciblée de l'énergie face à la protection de l'environnement, demandent un accroissement sensible des efforts de recherche. Une telle politique ne peut se concevoir sans recourir à un partenariat plus large et sans une incitation et un financement substantiel de la part de la puissance publique, française ou européenne.

Abstract

This article begins by recalling a statement made at the 15th World Energy Council (Madrid, September 1992): during the next 30 years, fossil energy sources will continue to be the basis for all energy supplies . By looking at the conditions of this assertion within a difficult geopolitical context, it shows that one of the privileged routes is to increase research efforts to make scientific and technological advances that will make it possible to fulfill the demand for oil and gas at the start of the 21st century. The R&D effort required to make oil and gas technologies available for the next decade calls for concerted research to be done, for only coordinated research will prevent the dispersal of French efforts (Fig. 6). Increasing economically exploitable reserves, mastering production costs and reducing the costs of gas chainsfrom producing fields to consumer regions, while ensuring environmental production, are the challenges that have to be faced. To cope with these expectations for the industry, great research efforts must be made in the corresponding scientific areas so as to gain a better understanding of phenomena and to develop the most suitable solutions (Fig. 7). The leading R&D axes to be promoted between now and 2000 are then explained. Reducing exploration risks requires, above all, a better petroleum assessment of basins. The progress expected will be based on the scaling up of 2D basin modeling to 3D modeling for assessing the ultimate reserves of a basin (Fig. 8 and Plate I). Improving the determining of the geometry of subsurface geologic structures will benefit from progress in structural imaging, whose aim is to obtain an assessment of the position and shape of seismic reflectors. These are geologic concepts (the understanding the geologist has of the architecture of deltaic or alluvial deposits, of different types of reefs, etc. ) which, based on geostatistics and expressed by numerical modeling, will make lithological interpolation among wells (Fig. 9 and Plate II), thus leading to the better characterization of reservoirs. In structures where there is already a good understanding of the formations, the progress expected for the years to come, thanks to geophysical techniques, will involve prestack inversion, which will ascertain important characteristics such as the presence of gas or even the distinction of two fluids as well as the obtaining of three-dimensional data. Concerning production from fields, the stakes for R&D are considerable since the problem is now to produce from the great majority of small and structurally complex fields, or even, in some countries, to resume production from fields hampered by a relatively rustic recovery method. Such undertakings are essentially based on a better understanding of reservoir dynamics. On line of reflection that is certainly important for the future will be to analyze behavior laws in complex cases. In this area as well, numerical modeling is what will synthesize all the data (Plate V). After the reservoir has been characterized and the production method decided upon, it is indispensable to ascertain the most effective ways of operating. In this area, the technical mastery sought after aims to reduce the cost-to-quantities produced ratio while ensuring environmental protection, for example such as replacing oil-base driling fluids by nonpolluting fluids. Achieving optimum production at less cost will require better use of the processing capacities already in place. This will be achieved by the development of multiphase production, in particular for marginal or deep offshore fields. Concerning new production systems and within a context in which oil companies are seeking to exploit marginal fields and deep-water discoveries under the best possible economic conditions, the Nomad project (Plate VI) for multiphase evacuation via a light floating support seems to be destined for a great future. To decrease costs, another alternative is to use automated and unmanned installations. Gas transportation often entails the constraint of exorbitant costs, thus compromising the competitivity of gas projects. This is especially the case for the international transport of natural gas in the form of LNG, which will expand in the most competitive markets only if decisive technological progress is achieved so as to bring about a substantial decrease in costs throughout the entire LNG chain. Lastly, the chemical conversion of natural gas into fuels or petrochemical base stocks may be considered as an alternative solution to liquefaction for production from gas fields very far away from the consumer markets. For both economic and environmental reasons, natural gas appears to be the best possible base stock for manufacturing synthetic fuels. All in all, scientific and technological progress required for the increasing of economically exploitable reserves, for gaining greater accessibility to oil and gas resources, and to better target use of energy in the face of environmental production, require an appreciable increase in research efforts. Such a policy is inconcevable without having recourse to more widespread partnership and without incentives and substantial financing by both French and European public authorities.