Compressor Selection for High-Pressure, High-H2S Application

An upstream operator in the Middle East was in the process of revamping a mature oil production installation in a project worth over $10 billion. The field was producing oil and associated sour gas with extreme H₂S fraction, high water and chlorine content.

The production plan envisaged 5 compression train services including Gas Lift and Gas Injection. Given the highly sour, acid, and wet nature of the associated gas, which is outside the oil & gas industry’s experience range, the selection of gas compressors, particularly the high-pressure ones, was extremely challenging.

The client needed a third-party with solid compressor selection experience in similar applications. Since MACH10’s consultants have been directly involved in the selection of virtually all high-H₂S high-pressure compression project built worldwide in the last 20 years, MACH10 was tasked to provide an analysis of each compressor including the preliminary selection (i.e.  machine type, model, configuration, driver and to identify issues to be addressed in the next project phase).

MACH10 reviewed the basic machine configurations, benchmarked the selection against the industry experience with emphasis on previous offshore and high H₂S experience, verified the experience in similar applications stated by the compressors suppliers, identified areas needing further attention with regards to sour service compression, identified potential aero- and rotor-dynamic design issues for the high-pressure machines, highlighted aspects of compressor component design needing further analysis in the FEED phase, identified key selection/design aspects that will improve reliability, made recommendations on material selection including fabrication aspects (critical for this high-H₂S application), anticipated key scheduled/unscheduled maintenance practices for comparable duty machinery.

MACH10’s analysis allowed the client to:

• Identify and shortlist the compressor manufacturers with the technical capabilities to design a machine for such a difficult, unreferenced application.

• Specify the key design features (i.e. type of head and shaft sealing systems, materials selection, etc.) to be included in the next phase’s tender.

• Identify the key safety and maintenance aspects for this application.