Mumbai’s business story does not end at Nariman Point, BKC or Lower Parel. A large part of the city’s industrial strength lies far away from the skyline, in the Arabian Sea. Offshore platforms, supply vessels, subsea pipelines, diving teams, marine engineers, fabrication yards and oilfield support companies quietly keep India’s energy system moving.
In simple terms, offshore companies are those that work on sea-based oil and gas projects, offshore platforms, subsea services, marine construction, offshore vessels, drilling support and engineering work. Mumbai is one of India’s most important offshore hubs because of Mumbai High, ONGC’s western offshore operations, nearby ports, marine talent and the presence of major engineering and oilfield service companies.
Based on Mumbai presence, offshore project experience, reputation, service range and 2026 relevance, here are the top 5 offshore companies in Mumbai.
1. Oil and Natural Gas Corporation Ltd. — ONGC
Address: ONGC Vasudhara Bhavan, Western Express Highway, Bandra East, Mumbai – 400051, Maharashtra.
ONGC is the most important name in India’s offshore oil and gas sector. Its Western Offshore Assets, Mumbai High Asset and Neelam & Heera Asset offices are located at ONGC Vasudhara Bhavan in Bandra East, while the 11 High Office Complex is at Dharavi, Mumbai.
ONGC operates major offshore oil and gas fields on India’s western coast. Mumbai High is one of the most important offshore oilfields in the country, and ONGC’s Mumbai offices play a key role in offshore production, planning, technical support and asset management.
In 2026, ONGC remains at the top because it is not just an offshore service provider; it is the main operator behind India’s major western offshore production assets. For engineers, geologists, marine professionals and oilfield workers, ONGC is one of the biggest names connected with offshore careers in Mumbai.
2. L&T Energy — Hydrocarbon Offshore
Address: Quadrant 4, 10th Floor, AM Naik Tower, L&T Campus, Gate No. 3, Jogeshwari-Vikhroli Link Road, Powai, Mumbai – 400072, Maharashtra.
L&T Energy’s Hydrocarbon Offshore business is one of the strongest offshore engineering and EPC names in Mumbai. Its offshore business contact address is located at AM Naik Tower, L&T Campus, Powai.
The company works across offshore platforms and modules, modular fabrication, brownfield modifications, subsea systems and pipelines, transportation and installation, decommissioning solutions and floating solutions. Its offshore page describes the business as delivering EPCIC solutions across the offshore energy value chain, from concept to commissioning.
In 2026, L&T Energy stands out because offshore projects need heavy engineering, fabrication strength, safety systems and project execution skill. Whether it is offshore platforms, subsea pipelines or energy transition-related offshore work, L&T remains one of Mumbai’s most reputed engineering companies.
3. Afcons Infrastructure Ltd.
Address: Afcons House, 16, Shah Industrial Estate, Veera Desai Road, Azadnagar, Andheri West, Mumbai – 400053, Maharashtra.
Afcons Infrastructure is a major engineering and construction company from the Shapoorji Pallonji Group. Its head office is located at Afcons House, Andheri West, Mumbai.
Afcons is highly relevant in this list because it has a dedicated Oil & Gas vertical covering onshore and offshore oil and gas projects. The company states that it has executed several large-value offshore oil and gas projects, including offshore process platform work for ONGC.
Afcons is also strong in marine and industrial infrastructure. Its marine work includes ports, harbours, jetties, dry docks, wet basins, breakwaters, intake structures, LNG tanks and material handling systems. The company says it has executed 235 marine and industrial projects across 15 countries.
In 2026, Afcons is one of the best offshore-linked companies in Mumbai for marine construction, offshore oil and gas EPC, ports and heavy infrastructure projects.
4. Greatship India Ltd.
Address: One International Center, Tower 3, 23rd Floor, Senapati Bapat Marg, Elphinstone Road West, Mumbai – 400013, Maharashtra.
Greatship India is a well-known offshore services company from Mumbai. Its head office is located at One International Center, Tower 3, Elphinstone Road West.
The Greatship Group describes itself as a provider of drilling and marine support services to the offshore oil and gas industry across the world. It owns and operates jack-up rigs and dynamically positioned vessels, which are important for offshore drilling and support operations.
Greatship is important because offshore oil and gas work cannot happen without specialised vessels, rigs, crews, safety systems and marine logistics. In 2026, it remains a strong Mumbai-based offshore company for drilling support, marine support vessels and offshore energy services.
5. SEAMEC Ltd.
Address: A-901–905, 9th Floor, 215 Atrium, Andheri-Kurla Road, Andheri East, Mumbai – 400093, Maharashtra.
SEAMEC Ltd. is one of India’s important offshore oilfield service companies. Its official contact page lists its office at 215 Atrium, Andheri-Kurla Road, Andheri East, Mumbai.
SEAMEC is known for Diving Support Vessel-based services. It provides subsea inspection, repair, maintenance, light construction and utility services for offshore oil production. Its profile also says that SEAMEC operates from its registered and corporate office in Mumbai and has played an active role in oil and gas developments on India’s west coast.
In 2026, SEAMEC deserves a place in this list because subsea and diving support services are critical for offshore platforms, pipelines and oilfield maintenance. It is especially relevant for people looking at offshore marine careers, diving support vessels, subsea inspection and offshore maintenance work.
Conclusion
Mumbai is one of India’s most important offshore business centres because it connects oil and gas production, offshore engineering, subsea services, marine construction and offshore vessel operations. ONGC leads as the main offshore oil and gas operator. L&T Energy is strong in offshore EPC and engineering. Afcons brings heavy marine and offshore construction strength. Greatship is important for drilling and marine support services. SEAMEC stands out in subsea and diving-support vessel operations.
Together, these five companies show why Mumbai remains a powerful offshore hub in 2026.