Mud gas isotope logging interpretive method in oil and gas drilling operations

摘要

A method of interpreting mud gas samples in a drilling operation of a target area. The method starts with obtaining a plurality of mud gas samples at a plurality of incremental depths of the target area. The plurality of mud gas samples are analyzed to find various isotopic data at each depth. The isotopic data of the mud gas samples are plotting on several charts to provide a visual representation of the isotopic data trends. The charts may include: depth versus ethane/methane; depth versus delta¹³C per mil; and depth versus delta¹³C and gas show. In addition, the percentage methane versus delta¹³C is provided on a separate chart. This percentage methane versus delta¹³C chart provides engineering and geological information such as the location of lithological hydrocarbon seals, barriers, and zones of good hydrocarbon communication (e.g., compartments). This engineering and geological information is then correlated with the other charts.