Tom Whipple: An energy consultant in Mexico City published parts of the study and later the Wall Street Journal got to examine the document. It seems there is only 825 feet between the gas cap over the oil and the water that is pushing into Cantarell from the bottom. This distance is closing at between 250 and 360 feet per year.The more pessimistic of the study's scenarios have Cantarell's production dropping from 2 million b/d to 875 thousand barrels a day by the end of next year and 520 thousand barrels a day by the end of 2008. If the pessimistic scenarios outlined in the PEMEX study come to pass, it will be very serious. The loss of nearly 1.5 million barrels a day of production capacity within three years will be very difficult to overcome either from other Mexican fields or from new production in other countries. Unlike political stoppages from exporters such as Iran or Nigeria , depletion can't be put right. Mexican exports will be seriously reduced or perhaps even eliminated forever.Of course, I am a big believer in technology and the power of markets. However, there is a limit to how quickly these mechanisms can produce alternatives.