Patent ID: 7526413
Filing Date: 2009-04-28
Classification: G01V

Abstract:
1. A method of analyzing data obtained from well logs taken in a subsurface geological formation having thinly interbedded sandstone and shale layers to determine an expected value of the hydrocarbon pore volume of the formation, comprising: (a) defining an initial model of the subsurface formation based upon estimates of different bed types and bed-type parameters in the formation, one of said bed-type parameters being aspect ratio, the initial model including a system of log equations for predicting well logs from bed-type parameters; (b) performing a Monte Carlo inversion to find the ranges of bed-type parameters consistent with the measured well log data, wherein performing the Monte Carlo inversion comprises computing distribution statistical data for interval hydrocarbon pore volume; and (c) generating a statistical distribution for hydrocarbon pore volume representing the expected value for, and an uncertainty in, the hydrocarbon pore volume from said computing distribution statistical data from said Monte Carlo inversion.