Abstract: A method is described for quantitative pay summaries from mud logs, real-time fluid typing, and to minimize logging expense in high-angle or horizontal wells. The method may include receiving at least one mud log; selecting extraction system type, operating, and drilling parameters for the at least one mud log; determining hydrocarbon parameters such as methane (C1) extraction efficiency, trap response factor (TRF), and relative responses for ethane-pentane (C2-C5); correcting gas-in-mud volume to an earth surface to generate a corrected C1-C5; calculating a gas-to-oil ratio (GOR) from the corrected C1-C5; calculating a reservoir gas volume from the gas-in-mud volume to an earth surface and the GOR; determining pay cutoffs; and generating least one pay summary. The method may be executed by a computer system.

Abstract: A method of detecting changes in return drilling fluid flow during drilling operations includes injecting at least one tracer gas at a measured rate into a return drilling fluid. A first sample of gases are extracted from the return drilling fluid at a location downstream of injection of the at least one tracer gas. A first concentration of the tracer gas in the first sample of gases is measured. A second sample of gases is extracted from the return drilling fluid at the location. A second concentration of the tracer gas in the second sample is measured. Changes in measured concentration of the tracer gas from the first and second samples are determined. The method includes using the change in measured concentration to infer a change in the flow rate.

Abstract: Methods and apparatus for improving the quantitative measurement and detection of gas entrapped in drilling fluid during a drilling operation are disclosed. A sealed gas sampler is provided for agitating the mud to evolve gas samples. A known quantity of a standard gas is injected into the evolved gas stream. By monitoring the quantitative amount of the standard gas measured, the samples of evolved gas may be corrected for various error sources such as gas saturation of the sample stream.