Patent ID: 7174254

Claim:
A method of interpreting sampled mud gas compositional and isotopic data in a drilling operation of a target area, said method comprising the steps of: obtaining a plurality of mud gas samples from a target area; analyzing the plurality of mud gas samples to obtain hydrocarbon compositional and isotopic data from the samples; plotting the hydrocarbon compositional and isotopic data upon a chart or well log, wherein the step of of plotting the isotopic data upon a chart includes plotting a percentage methane versus isotopic composition; determining a trend of a plurality of points upon the chart; deriving from the chart or log an interpretation of the log indicative of hydrocarbon communication: and wherein the chart or log forms a mixing line derived from an approximately straight line or other trend comprised of at least three data points upon the plot, the indentified mixing line being indicative of a zone of good hydrocarbon communication and compartmentalization.