ONGC’s Journey: Mumbai High Is 50 Not Out And Going Strong

The Bombay High was discovered a year before Sholay hit the screens, both considered iconic by the then Prime Minister Indira Gandhi. She remembered how her father, Jawaharlal Nehru, had asked the Planning Commission to set aside funds for ONGC’s oil exploration.

Nehru had even told the young engineers of ONGC that they should not let him down. It was in 1956 when ONGC was formed. And while it discovered oil onshore within a couple of years, it could only look at offshore options after a decade. ONGC began offshore surveys off the Gujarat coast in the late 1960s and ultimately found oil, and then gas, in the Arabian Sea in 1974.

Half a century has passed, and both Bombay High and Sholay retain their glory. ONGC started extracting black gold in 1976 and continues its operations to date. Sholay continues the set the Bollywood bar.

It was a significant year for India. Veteran Gandhian socialist Jayprakash Narain started his agitation against corruption in Bihar, India triggered a nuclear blast in the Thar desert, a 20-day-long railway strike turned out to be the world’s largest recorded industrial action, and would be Bollywood icons like Karishma Kapoor and Farhan Akhtar were born.

The New York Times had once observed that the normal life cycle of an oil or gas field is a little like that of a human being: It is brought into life with expectation, produces vibrantly for a time, steadily declines, and then is buried under clean soil. But that is not true for Bombay High, located some 160 km in the Arabian Sea off India’s western coast. It has produced 527 million metric tonne of oil and 221 billion cubic meters of gas, totalling 70% of India’ domestic production.

Now, it produces 133,000 barrels of oil every day, along with 10 million cubic meters of gas. That is 35% of India’s oil production and 18% of India’s gas production. Even after half a century of continuous production, the Mumbai High field is going strong, considering that the annual decline rate is below 4.5% compared to the international figures of 8-10% for fields of similar size and age.

ONGC, it is reliably learned, has embarked on revitalizing Mumbai High using advanced artificial intelligence/machine learning-based simulation models and low saline water injection in 2022, the first of its kind in offshore carbonate reservoirs. The company has also completed its advanced seismic data acquisition that will help ONGC understand the levels of fluid movement in the main and minor reservoirs. And this could well turn out to be another Mumbai High within the existing Mumbai High.

ONGC continues to bet high on Mumbai High, evident from its huge capex investment for the redevelopment plans. Speaking at a recent energy conference, ONGC Chairman and Chief Executive Officer Arun Kumar Singh expressed hope of discovering a new field similar to Mumbai High soon. Two years ago, ONGC said it had plans to invest more than $500 million to boost hydrocarbon production in its flagship asset, Mumbai High.

Top ONGC executives say Bombay High is top priority for the company. “Mumbai High (no longer Bombay High) saved us the blushes of being a huge oil and gas importer. It gave India energy and economic security,” says C Mathavan, ONGC’s executive director, who has been working at Mumbai High since 1997. 

The field was discovered in February 1974 by the Russian and Indian team from the seismic exploration vessel Academic Arkhangelsky while mapping the Gulf of Cambay. Earlier, a team of geologists from the US had visited India for mapping and told New Delhi it should not waste time looking for oil and gas in the Arabian Sea.

“The geologists from the West were very surprised when we found oil,” Mathavan said in an interview. Bombay High commenced production on May 21, 1976. The field initially produced 3,500 barrels of oil per day and within three years, it reached 80,000 barrels per day. The field hit a peak of 4,76,000 barrels of oil per day and this amounts to peak production of 20 MMT in a year in 1989. A subsea pipeline in 1978 took the oil from the field to Bombay refineries.

Bombay High was magical for ONGC engineers. Old-timers recollect how the rich and famous of Bombay used to see skies of red while venturing out in the Arabian high seas in their expensive vessels; it was the light from the gas flare at the offshore platforms.

A Japanese-built jack-up, self-propelled, self-elevating drill ship aptly named Sagar Samrat was pushed into service after it had drilled a well at Tarapur structure without success. The ONGC engineers were depressed with the Tarapur failure but regained composure and deployed Sagar Samrat at another well near Bombay High. It was big action on the high seas.

The engineers were worried when on Jan. 31, 1974, the four huge legs started going down simultaneously. Eventually, it hit solid ground under the seabed, and the ship was jacked up, 50 feet above water. And a few days later, on Feb. 3, 1974, the drill string went down to touch the seabed, called spudding in the industry parlance. At 962 meters, the sample was studied by the engineers and geologists; it showed "golden yellow" fluorescence- the color of oil. And then, when the core sample was studied, there were streaks of oil band on the outer surface of the rock. It was too good to be true.

A special Drill Stem Testing—the only one available in India—was sought from Ahmedabad. On February 19, 1974, at the break of dawn, the well was opened and oil gushed out in great force. The engineers measured its gravity; it was 43.6 degrees API, another astounding parameter. In oil field parlance, 43.6 degrees API was as good as gold. India’s energy landscape changed forever.

The success of Mumbai High also triggered a subtle tussle between the ONGC top brass and bureaucrats from the Ministry of Petroleum and Natural Gas, the latter repeatedly trying to exert both pressure and influence over ONGC engineers to speed up production. Often, the demand from the ministry was grossly unrealistic. Every minister wanted to push numbers to showcase success.

“The ping pong game continued because the bureaucrats, and at times the minister, wanted the ONGC top brass at their beck and call and demand more production as if there is no tomorrow. And those who defied orders were sidelined,” said a top energy expert on conditions of anonymity.

Former ONGC Chairman Subir Raha’s run-ins with the then oil and gas minister Mani Shankar Aiyer are well documented. Raha wanted total autonomy for ONGC, and the minister would have none of it. Raha was denied an extension after he was involved in a public spat with Aiyer. Worse, Raha’s woes were compounded with Petroleum Secretary TNR Rao’s adverse report on the fire that devastated an oil installation on the Mumbai High field in 2005. The ministry’s interference continued for a very long period. Things, however, have changed.

The government now wants its most successful PSU to get more out of Mumbai High. India’s Minister of Petroleum & Natural Gas and Housing and Urban Affairs Hardeep Singh Puri has described Mumbai High as an extraordinary and glorious journey. He has urged ONGC to deploy cutting-edge technologies like AI and data analytics for both sustainability and reduced environmental impact.

Mumbai High has about 2.2 billion tonne of oil and gas reserves in place in the two blocks, Mumbai High North and Mumbai High South, out of which the current recovery is close to 30 percent.

The future of Mumbai High lies in a combination of ongoing projects, exploring advanced technologies, and potentially expanding exploration efforts. While the field's natural decline is inevitable, the proactive measures being taken can extend its productive life and continue to contribute to India's energy security.

“Mumbai High still has years, rather decades of productive life, and will energise the country well into the 2040s and 50s. And, if at all the fields reach the economic limits of production, the facilities can be decommissioned safely or put into alternate uses like artificial reefs and of course tourists spots for those who want to spend time in the high seas. But that’s a wild guess. Samudra manthan ka pachas saal, bhavishya ab bhi bemisal,” says Mathavan.

Who knows, India’s honeymoon couples—always looking for exotic locations—could eventually land up in Mumbai High for total nirvana.

Shantanu Guha Ray is the Asia Editor of Central European News. He is author of 'Black Harvest: The India Coal Story' that will hit the stands in a few months.

The views expressed here are those of the author, and do not necessarily represent the views of NDTV Profit or its editorial team.