OIL, GAS AND THE ENVIRONMENT - WHAT APPRO ACH BY RESEARCH-AND-DEVELOPMENT IN EXPLORATION-PRODUCTION FOR THE END OF THE CENTURY

This article begins by recalling a statement made at the 15th World En ergy Council (Madrid, September 1992): ''during the next 30 years, fos sil energy sources will continue to be the basis for all energy suppli es''. By looking at the conditions of this assertion within a difficul t geopolitical context, it shows that one of the privileged routes is to increase research efforts to make scientific and technological adva nces 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 d ispersal of French efforts (Fig. 6). Increasing economically exploitab le reserves, mastering production costs and reducing the costs of ''ga s chains'' from producing fields to consumer regions, while ensuring e nvironmental 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 bet ter understanding of phenomena and to develop the most suitable soluti ons (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 assess ing the ultimate reserves of a basin (Fig. 8 and Plate 1). Improving t he 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 archite cture of deltaic or alluvial deposits, of different types of reefs, et c.) 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 struc tures where there is already a good understanding of the formations, t he progress expected for the years to come, thanks to geophysical tech niques, will involve prestack inversion, which will ascertain importan t characteristics such as the presence of gas or even the distinction of two fluids as well as the obtaining of three-dimensional data. Conc erning production from fields, the stakes for R&D are considerable sin ce the problem is now to produce from the great majority of small and structurally complex fields, or even, in some countries, to resume pro duction from fields hampered by a relatively rustic recovery method. S uch undertakings are essentially based on a better understanding of re servoir dynamics. On line of reflection that is certainly important fo r the future will be to analyze behavior laws in complex cases. In thi s area as well, numerical modeling is what will synthesize all the dat a (Plate V). After the reservoir has been characterized and the produc tion method decided upon, it is indispensable to ascertain the most ef fective ways of operating. In this area, the technical mastery sought after aims to reduce the cost-to-quantities produced ratio while ensur ing environmental protection, for example such as replacing oil-base d riling 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 prod uction, in particular for marginal or deep offshore fields. Concerning new production systems and within a context in which oil companies ar e seeking to exploit marginal fields and deep-water discoveries under the best possible economic conditions, the Nomad project (Plate VI) fo r multiphase evacuation via a light floating support seems to be desti ned for a great future. To decrease costs, another alternative is to u se automated and unmanned installations. Gas transportation often enta ils the constraint of exorbitant costs, thus compromising the competit ivity of gas projects. This is especially the case for the internation al transport of natural gas in the form of LNG, which will expand in t he most competitive markets only if decisive technological progress is achieved so as to bring about a substantial decrease in costs through out the entire LNG chain. Lastly, the chemical conversion of natural g as into fuels or petrochemical base stocks may be considered as an alt ernative solution to liquefaction for production from gas fields very far away from the consumer markets. For both economic and environmenta l reasons, natural gas appears to be the best possible base stock for manufacturing synthetic fuels. All in all, scientific and technologica l progress required for the increasing of economically exploitable res erves, for gaining greater accessibility to oil and gas resources, and to better target use of energy in the face of environmental productio n, 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 E uropean public authorities.