Pri n ce Co n sort R oad , South Ken sing ton , London , SW7 26P . Un ited Ki n gdom Email : j . n .ca rter@ic . ac. u k
Abstrac tThe use of automated inversion methods to condition numerical reservoir models to both static data (we)l-logs) and dynamic data (production data) is becoming more important . It is essential that any methodology should be : robust to problems in the numerical simulation ; able to handle all of the different classes of variables present ; and be efficient both in terms of the number of simulations required and the wal)-clock time taken .In this paper we demonstrate that by using a combination of : geostatistical interpolation ; a pilotpoint method ; and a Genetic Algorithm, one can successfully match a complex Brent sequence reservoir to both production and wel)-log data . The reservoir is a version of the PUNQ Complex Model, which consists of a realistic Brent sequence, within a complex fault system . There are Bleven producers and six injectors, and a total of four years of production was used in the test . The model is characterised by using 513 points for the permeability, the porosity and the net-togross ratio . An additional group of 24 variables are used to control the geostatistical properties, the fault properties, and the wel)-skin factors, this gives a total of 1563 variables .The Genetic Algorithm used was the standard generational replacement with elitism method . The structure of the genome and the crossover operators veere specially designed for the problem being tackled . Using fust 400 numerical simulations it was possible for the methodology to obtain a match similar in quality to that which might be obtained by a good reservoir engineer . Using 20 computers the wal)-clock time taken would have been equivalent to the time taken by 20 numerical simulations . The method we have used is robust to loss of simulation results, able to handle many classes of variables simultaneously and is efficient .