INMACO - Nitrogen Generation for Safety and Loss Prevention

INMACO provide safety and loss prevention engineering services, process systems and as safety contractors. We combine industry skills, experience and an understanding of our products to meet the specific requirements of our customers through project execution and integrated solutions.

Through subsidiaries, affiliates and agent networking INMACO's goal is to be a global oil and gas industry provider of safety engineering and contracting services, integrated solutions and advanced technology products.

NITROGEN GENERATION

Inert gas is used for blanketing and purging of chemical tanks, and for purging of equipment and systems before maintenance. The inert gas system can be divided into three sub-systems:

• Nitrogen generator/source
• Storage system
• Distribution system

NITROGEN GENERATOR PACKAGE

The nitrogen gas generator package uses membrane separators to produce nitrogen from compressed air. It is a skid-mounted unit, complete with all necessary instrumentation and controls for unattended operation.

Dry, compressed air is fed to the nitrogen generation package from the FPSO air system. The pneumatic operated isolation valve located at the skid feed air inlet will open at system start-up allowing air to flow into the skid for nitrogen separation. The feed air passes through the particle filter which filters all particles above 0.01 micron size.

Pressure drop across the filter will be continuously monitored by a differential pressure-indicating transmitter. A high alarm will indicate clogged filter element and requirements for replacing. Two 100% capacity filters are included hence filter element can be replaced while in operation.

TYPICAL OPERATING/DESIGN CONDITIONS

Typical supply pressure is 6barg - 9barg when using plant air feed. Typical design and operating criteria for the main equipment:

• Feed air pressure: 6barg - 10barg
• Feed air temperature: 30°C - 50°C
• Feed air particle size: 3µ
• Feed air dew point (at 10bar) -25°C
• Oil free feed air Less than 0.01mg/m&179;
• Design pressure: 8barg - 13.5barg
• Design temperature, min/max -10°C / 60°C

NITROGEN GENERATOR CONSUMERS

Typical consumers of Nitrogen generation include:

• Produced water flash drum
• Compressor gas seals
• Produced water disposal caisson
• Heating medium expansion vessel
• Methanol storage tank
• Low pressure flare header
• Atmospheric vent header
• Hazardous open drain sump
• Closed drain flash drum
• Reclaimed oil sump
• Heave compensation

Nitrogen is used extensively for drilling, completion and workover of oil and gas wells, also for pressure maintenance and gas storage in condensate formations. It can be generated on site at high pressures and low oxygen levels to safely prevent ignition of flammable gases or protection of field tubulars from downhole corrosion.