In a move that has the potential to open up a new exploration play & contribute to strengthening the country’s energy security, the consortium of ONGC and Essar made a natural gas discovery in the Mumbai Offshore Basin. The discovery was made in the first exploratory well MBSO53NAA1 in Block MB-OSN-2005/3 in the Mumbai Offshore Basin, which was awarded under New Exploration Licensing Policy (NELP) VII Round.
The discovery is significant geologically because it’s the first on the west coast in the Pliocene formation, with the reservoir depths being about 1000 metres. The presence of gas at a shallower depth can significantly bring down both costs and the time period involved in commercialising the find, thereby ensuring a quicker access to potential gas reserves. The Operator, on behalf of the Consortium, has filed details of the discovery with the Directorate General of Hydrocarbons (DGH).
During the conventional testing of the discovery, gas flowed at around 47,000 standard cubic metres per day (scmd) through a 32/64” bean. In a secondary and shallower reservoir object, gas was also encountered during MDT and DST. The Pliocene exploration target was mapped based on a high quality 3D Seismic data acquired by Essar, as Operator, during Phase I of the Exploration Period. Presently, ONGC with 70% participating interest, is the Operator. The Consortium finds the results encouraging and shall be appraising this discovery to establish the reserves.
India is the fourth largest primary energy consumer after China, USA and Russia. Currently, 56% of India’s primary energy requirement is met through coal. The next big contributor of India's consumption of primary energy is crude oil, accounting for nearly 28% of the total energy basket. Natural gas accounts for 7.15% while nuclear energy (1.26%), hydropower (4.64%) and renewables (2.2%) together account for close to 8% of our energy demands, as of 2015.
To address the issue of hydrocarbon import dependence of the Nation, Hon’ble Prime Minister, Shri Narendra Modi had, at the Urja Sangam in 2015, emphasised to work towards achieving energy security and urged all the stakeholders to increase domestic production of oil and gas to reduce import dependence from 77% to 67% by year 2022, being the 75th year of independence. Towards this objective, discoveries in new and existing hydrocarbon plays in India present opportunities to contribute towards energy security target.
As per a recent news report, analysts estimate that the total resources could be of the order of in the 350-500 bcf (billion cubic feet) though the estimates should be considered as premature and should be defined based on outcome of appraisal programme. Owing to the relatively shallower depth of the find, if the discovery becomes commercial, it is expected that the time to market should be relatively less due to possible utilisation of existing infrastructure in Mumbai Offshore. The Mumbai High reservoirs are typically at a depth of 2,000-2,500 m while the current find in the Pliocene formation is at a depth of 1,000m.