The Mid Tapti and South Tapti Fields are operated by the Panna Mukta Tapti Joint Venture (PMT JV) under the Production Sharing Contract (PSC) executed with the Government of India. In accordance with the Tapti PSC and applicable laws, BGEPIL is required to decommission the Tapti Part B facilities. The removal of STB platform and STB-TPP bridge are part of this decommissioning scope.

A HAZCON was conducted to assess risks in removal of STB platform and STB-TPP bridge in the vicinity of TPP-TCPP Complex. Participants representing PMT JV and ONGC (B&S Asset, Engineering Services) participated in this HAZCON. The workshop was chaired by MCE representatives.

Challenges:

• Unique and first of its kind activity in the Indian waters.
• The key components of the TPP-TCPP complex that may be impacted due to risks during removal were:
• Living Quarters with minimum 70 people always staying in it;
• Export sales gas pipeline originating from TPP;
• TPP jacket which has served its design life;
• TPP helideck is the only helideck for TPP-TCPP process complex.
• One main pile (B2) of TPP platform has achieved 50% design penetration.
• Strong tidal currents, tidal changes, shifting sands, and poor visibility (for diving operations) in Tapti Field.
• Extensive potential risk due to large Marine Spread to be stationed at / around the TPP-TCPP complex (for cumulatively ~7 weeks.
• Anchor wires potentially going below the Process Complex bridges for positioning of the barges.

Any uncontrolled movement of heavy lift barge crane during lifting of bridge may lead to collision/ dropped object scenario at TPP Process Complex piping & risers.