Estimating the Ultimate Recoverable Reserves of the Paris Basin, France

The Paris Basin is a mature basin from an exploration point of view. More than 800 exploration wells have been drilled over the last 40 years and 52 fields have been discovered from which 33. 4 Mt of petroleum have been produced by the end 2000. Based on past production data, the future exploration and production potential of the Paris Basin is estimated using classical statistical methods. The mean size of a field in theParis Basin is about 100 000 t with a 5% chance of a field whose size is greater than 2. 5 Mt. The ultimate recoverable reserves based on the creaming curve analysis were about 15 Mt in 1986, 29 Mt in 1991 and 46 Mt in 1996. At present, there is a 5% chance of finding a field in the Dogger and Keuper formations that is bigger than 4 Mt. The drilling success ratio increases from 1/66 for the shallowest, the Cretaceous Neocomian formation to 1/8 in the deepest and latest to be drilled Triassic Keuper formation. The data analysis presented in the paper is based on known production data which do not take into account additional production gained by enhanced recovery methods or additional reserves added by discoveries based on new plays, that however may significantly increase reserves beyond the numbers presented here as the creaming curve analysis has shown