Mud-gas extractor and detector comparison

Although many gas extractors and detectors currently exist, there is no significant comparison between the data quality that they produce. Most advances in mud-gas interpretation and deployable new technologies were driven by service companies' needs to provide operators with the highest standards of data and interpretation while using their most cost-effective systems for mud-gas analysis. This led to rapid growth in the mud logging sector for providing more scientifically rigorous services at the rigsite. Each new method provided a suite of applications and, more importantly, limitations; a comparison study was performed to gather this information. The comparison study focused on quantitative gas measurement (QGM), constant volume (CV), and constant volume and temperature (CVT) extractors with gas chromatographs (GC) and mass spectrometers (MSs). These systems were compared by operating them simultaneously at the rigsite. The CVT system with MS outperformed all other systems. The QGM and CV gas extractors lacked the consistency observed in the CVT system, and the QGM and CV extractors failed to consistently extract C3+ components from the drilling fluid. The MS on the QGM and CV systems added limited value resulting from using atmospheric air as the carrier gas and the lack of a constant temperature. Although the installation of the CVT is more costly and time consuming, these issues are offset by the additional information and consistency provided by the CVT. Comparing the three extraction systems with two different gas detectors helped determine the best solution on a cost and necessary information basis.