India’s ONGC, one of the largest Asia-based oil and gas exploration and production companies, has announced that it may have discovered third largest field in India’s Western Offshore Basin.
While carrying out development drilling in D1 Field, ONGC discovered a new pool of reserves which may catapult D1 to become the third largest field in Western Offshore after prolific Mumbai high and Heera. Earlier the D1 was known to have IOIP (Initial Oil In-place) to the order of 600 million barrel (82.20 million tonne oil equivalent). After the discovery of the new pool, its total IOIP is expected to be in excess of One Billon Barrel (140 mtoe).
D1, primarily an oil producing field, is situated about 200 km West of Mumbai city in Deep Continental Shelf at a water depth of 85m – 90m. The Field comprises of 4 blocks namely D1-4, D1-12, D1-14 and D1-2/5.
The first well in D1-4 block was drilled in the year 1976. The low Gas to Oil Ratio (GOR) and the then understanding of reservoir led to slow pace of exploration and appraisal of the field. As a result, the first development scheme for the D1 Field was confined only to the D1-4 Block in which a total 12 wells were drilled in two phases. After completion of Phase-II, the field achieved a peak oil production of 17,500 BOPD in the year 2009. Currently, D1 is producing on an average of 12,500 bopd.
In the next phase of development, ONGC is presently implementing an Integrated Development Plan for D1 Field. Three new well platforms namely D1-B, D1-C and D1-D have been commissioned in 3 different blocks viz. D1-4, D1-12 and D1-14. Development drilling activities in the blocks of D1-4 and D1-14 have been taken up, which will increase the production from current level of 12,500 to 36,000 bopd by February, 2013
The first development well (D1-D#1) in the block of D1-14, spudded in May, 2012, was initially planned to be drilled up to a depth of 2648 m. On noticing presence of oil in the zone of 2635-2640m, it was decided to drill 100m further. This entire 100 m encountered oil bearing sand. Subsequently the well was drilled up to a depth of 2830m.
This discovery, notified to DGH, has unfolded an additional oil bearing zone of about 142m. On complete development of the field D1, the production is expected to go up to 60,000 bopd. This additional development program will start yielding results from January, 2014.
CMD, ONGC Sudhir Vasudeva exuberated on this discovery and said, ‘This discovery indeed has come up with a lot of promise signifying a substantial increase in the production for the company. Finally we have made it to a large discovery which was eluding us for long’.
Press Release, August 13, 2012