Oil & Natural Gas Corporation Limited (ONGC) is flag bearer of energy security for the nation. With significant Government thrust on increasing Oil & Gas production in India, ONGC planned third phase of Mumbai High North field redevelopment, to boost production by 23 per cent by 2019-20, involved a capital investment of Rs.5813.25 Crores including the facilities cost of Rs. 2693.20 Crores. The implementation of the project will lead to incremental gain of 6.997 million tonne (MMT) crude oil and 5.253 billion cubic metres (BCM) gas by 2030.
The strategy of Mumbai High North Re-Development (MHNRD Phase-III) scheme includes opportunities for further development of LI, LII, S1 and other minor reservoirs along with the major LIII reservoir and integrating the required inputs. Facilities for MHNRD Phase III were planned to be created under two separate Contracts i.e. 5 Well Platform Project (WPP) and Pipeline Project (PLP).
L&T Hydrocarbon Engineering Limited (LTHE) secured the EPC contract for MHNRD Phase III 5 Well Platform Project (MHNRD-3) worth USD 219 Mn on August 11, 2014. The formal contract was signed in September 2014.
The project award also coincided with 'Make in India' initiative launched by the Government of India. LTHE's has major fabrication facilities in India, which include two modular fabrication yards, one at Hazira (Gujarat) on the West coast and other at Kattupalli (Tamil Nadu) on the East coast.
Project Scope
The scope of work for MHNRD-3 Project includes Surveys (Pre-Engineering, Pre-construction/ pre-installation and post-construction), Design, Engineering, Procurement, Fabrication, Load out, Tie down/ Sea fastening, Tow-out/Sail-out, Transportation, Installation, Hook-up, Testing, Pre-commissioning, and Commissioning of new well head platforms N19, N21, N22, N23 and N24. It also included modification works on MNW platform, installation of 3 Clamp-on Structures along with 6 Deck Extensions at N11 Platform and underwater strengthening of jacket with grouted clamp at NQD Platform.
Well platforms facilities include Production header, Test header, 2-phase Test separator, Solar Power system, Hydro pneumatic shut down panel, Deck crane and SCADA.
The project was slated for completion in March 2016. This was a moderate challenge in terms of schedule, for the Engineering, Procurement & Fabrication phase, considering the aggressive timelines delivered by LTHE earlier. The installation schedule was very critical considering requirement of complete installation and commissioning of all facilities within 5 months from start of installation campaign in November 2015.
Engineering
LTHE's Engineering Centre in Bangalore, which specialises in engineering of offshore structures, carried out the detailed engineering for the project. The engineering centre was established in 1992 as John Brown Engineering India Ltd. It was taken over by L&T in 2004 and named L&T Valdel Engineering Limited. Recently this Engineering Centre was merged with parent company i.e. LTHE and now operates as the engineering arm of Offshore Business Vertical.
This Engineering Centre in Bangalore has many credentials to its account, which include engineering of the mammoth and complex MHN Process Platform Project executed by LTHE between 2009-12. The Engineering Centre in Bangalore has performed detail engineering and modifications for over 200 platforms. Engineering for 5 wellhead platforms enhances total no. of wellhead platforms engineered by LTHE to 40, a distinction for an Indian Company.
The engineering of two platforms was very critical considering the load and jacket weights, which were bordering the lift capacity of planned installation vessel. A little increase could have forced change in installation methodology from lift to launch, and resulted in major changes in execution philosophy. Structured weight monitoring approach and focus on equipment layout optimisation, proper integration and weight control of major vendor packages helped to manage the lift weight of jacket & topsides thus mitigating major risks to timely completion.
Procurement
Procurement for the project was done expeditiously thanks to LTHE's vast network of suppliers around the globe which ensured that the delivery of materials and equipment did not hinder the fabrication processes in any way. The key topside packages were procured quickly and delivered at the yard as planned. This was achieved without any deviation from the approved vendor list and stringent material testing requirement as per contract.
Fabrication
This project was especially challenging considering only 19 months' duration to complete entire scope of work and handover the facilities to ONGC. Complete fabrication was done with in-house facilities. In line with the 'Make in India' campaign most fabrication work was carried out in India at LTHE's Modular Fabrication Facility at Hazira, Gujarat. This included 3 Jackets, 5 topsides, Piles and all modification works. Only two jackets were fabricated at LTHE's Modular Fabrication yard at Oman to meet installation schedule requirements.
Precise planning, engineering, synchronized teamwork and coordination across the facilities allowed all structures to be ready ahead of schedule and sail out without any punch points.
Meanwhile, ONGC requested for early completion and handover of N19 platform, one month ahead of original schedule. In line with LTHE's philosophy of meeting customer expectations, the whole team rose to the occasion. N19 Topside fabrication was accelerated and completed ahead of time. This was well appreciated by the client as they could start early production.
Installation
The offshore installation work was subcontracted to an established third party. The installation season began with installation of jacket for N21 Platform followed by N19 Platform and DO Tower installation.
Four platforms and modification at three existing platforms were completed and handed over to ONGC progressively by 27th March 2016 ahead of contractual completion date of 31st March 2016. Due to discrepancy in relied upon soil data and actual soil behaviour, N-23 Platform was completed and handed over to ONGC on 15th May 2017.
For LTHE, the MHNRD Phase III 5 Well Platform Project has been a story of perseverance and overcoming challenges, which few other could have faced. A true team effort, the credit for its successful completion is due to everyone who worked on it.
