SKEWED-NORMAL PRODUCTION-PROFILE MODEL AND REVERSE-PROJECTION TECHNIQUE FOR RESOURCE AND SUPPLY PREDICTIONS

This paper discusses a unique approach to the mathematical modelling of the extraction life-cycle of any depleting fossil-fuel resource and is applied to crude-oil and natural-gas production. The skewed-normal production-profile (i.e. production rate versus time) model, (i) yields a better representation than can be achieved with earlier approaches, and (ii) is appropriate for use with production data that rise quickly with time to a peak and then slowly decline, but is unsatisfactory for use when the profile exhibits more than one peak. In many circumstances the profile is less systematic in shape, often as a result of temporary political, economic or on-stream factors. Under such circumstances, it is suggested that the skewed-normal production-profile (SNPP) model be used in conjunction with the reverse-projection (RP) technique. The application of the model, without and with a reverse projection through the data, is demonstrated briefly using UK crude-oil and natural-gas production rates.