top of page

LSTK execution of three high capacity enclosed ground flare systems for ONGC’s gas production facilities in Assam

  • Jun 5
  • 2 min read


Client: Oil and Natural Gas Corporation (ONGC)

Sector: Oil & Gas

Status: 2 sites fully commissioned, 3rd site in final commissioning

Application: Combustion of relief gases

Inlet Gas: Methane-rich

Capacities:

  • Site 1: 17,500 Nm³/hr (Stack Height: 16 m)

  • Site 2: 108,416 Nm³/hr (Stack Height: 18 m)

  • Site 3: 55,000 Nm³/hr (Stack Height: 18 m)


Overview

As part of ONGC’s drive to modernize its flare infrastructure and eliminate atmospheric venting, CRA was awarded a Lump Sum Turnkey (LSTK) contract to design, engineer, and install new enclosed ground flares across three installations in Assam.


These revamps were aimed at:

  • Improving safety by eliminating outdated open vent stacks

  • Enhancing environmental compliance with OISD and other norms

  • Providing long-term, reliable combustion systems for relief gases


The project scope included complete system replacement, from flare headers to seal drums and knock-out vessels, with all civil, structural, mechanical, electrical, and instrumentation works delivered under a single integrated contract.

CRA worked closely with site teams across the fields, navigating live plant constraints, legacy tie-ins, and aggressive commissioning targets.


Scope of work


CRA’s turnkey scope included:


  • New flare systems with sub-header integration

  • Catch Pots, Knock-Out Drums, Seal Drums and associated pumping systems

  • Pilot ignition network routed from FFG/PLC panel

  • Complete civil work, including design simulations, and in-situ concrete piles

  • PSV/PCV modifications, including isolation upgrades for safer maintenance

  • Complete utility piping (pilot gas, service water, instrument air)

  • Controlled shutdowns and tie-ins across live operating areas

  • Full QA/QC, documentation, and compliance with OISD, DGMS, and CPCB


Challenges and Solutions

Challenge

CRA's Solution

Remote multi-site coordination

Modular execution teams deployed in parallel

Integration with undocumented legacy piping

Comprehensive pre-bid surveys and 'as-existing' validation

Hot work in live plant

Phased shutdown planning with strict safety permits

Infrastructure variability

Customized tie-in and layout solutions for each installation

Performance Assurance


Each flare system successfully commissioned has passed a 72-hour Performance Guarantee Test Run, confirming:


  • Emission control

  • Mechanical integrity

  • Long-term reliability

 
 
bottom of page