Patent ID: 6808028
Filing Date: 2004-10-26
Classification: G01V

Abstract:
A method of gathering information on the pore pressure in an earth formation surrounding a wellbore, the wellbore and the surrounding earth formation defining a drilling environment, said method comprising the steps of:(a) selecting at least one suitable property of the drilling environment, whereby values of the suitable property over a plurality of wellbore depths can be correlated with the characteristics of the pore pressure in the earth formation; (b) selecting at least one NMR parameter of an NMR measurement response; (c) conducting an NMR measurement at a plurality of wellbore depths, thereby generating an NMR response from the drilling environment; (d) correlating values of the NMR parameter in the NMR response with values of the suitable property; and (e) determining characteristics of the pore pressure in the earth formation over the plurality of wellbore depths by comparing values of the suitable property over the plurality of depths, and correlating the correspondence between the values with the characteristics of the pore pressure over the plurality of depths.