One-Minute Analysis of Mud Logging Gas Using the Agilent 990 Micro GC

Significance of the Topic

Rapid quantification of mud logging gas in oil and gas exploration is essential for identifying productive formations and optimizing drilling operations. One minute analysis improves decision making in real time and enhances safety by monitoring hydrogen sulfide and other hazardous gases.

Objectives and Overview of the Study

The study introduces a method using the Agilent 990 Micro GC to achieve complete separation and quantification of permanent gases and hydrocarbons up to C8 within 40 seconds, reducing the total analysis cycle to under one minute.

Methodology and Instrumentation

The 990 Micro GC was configured with three separation channels:

• Channel 1: 1 m plus 10 m Agilent J&W CP-Molsieve 5Å with backflush and retention time stability filters for H2, O2, N2 and CH4.
• Channel 2: 1 m plus 10 m Agilent J&W PoraPLOT U with backflush for CO2, ethane, H2S, COS and propane.
• Channel 3: 4 m Agilent J&W CP-Sil 5 CB for C4 to C8 hydrocarbons.

Helium served as carrier gas with column pressures between 250 and 300 kPa. Injection times ranged from 20 to 40 ms with backflush enabled for channels 1 and 2. A fully inert flow path allowed low ppm level detection of sulfur species.

Main Results and Discussion

• All analytes eluted within 40 seconds with retention time RSD below 0.1% and area RSD below 1%.
• Lower detection limits were in the ppm range for channels 1 and 2 and sub-ppm for channel 3.
• Hydrogen detection at high concentration showed non-linear peak behavior with helium carrier gas.
• Inert sample line provided robust analysis of hydrogen sulfide at ppm levels.

Benefits and Practical Applications

Rapid one minute analysis supports real time mud logging, enabling early detection of producible zones and hazardous gases. The compact Micro GC platform is suitable for field deployment in drilling rigs and remote operations.

Future Trends and Possibilities

• Integration of advanced detectors to lower detection limits.
• Automation and remote monitoring for continuous gas analysis.
• Expansion to additional analytes and real time data analytics with machine intelligence.
• Development of miniaturized modules for on site laboratory applications.

Conclusion

The Agilent 990 Micro GC provides a high performance solution for sub-minute analysis of mud logging gases, offering excellent repeatability, sensitivity and portability for field analytics.

References

1. Zhang J Rapid Analysis of Mud Logging Well Gas Using the Agilent 990 Micro GC Agilent Technologies application note publication number 5994-1039EN 2019
2. Toonen A Hydrogen Detection with a TCD Using Mixed Carrier Gas on the Agilent Micro GC Agilent Technologies application note publication number 5991-3199EN 2013