Oil India Limited
The story of oil exploration in India began in the dense jungles and swamps of Assam in the 19th century. United by geography with Burma and caught up in the cross-currents of history, the region had the common blessing of commercial oil.

Digboi Well No-1(1889-1890)
The well, started in September 1889, was completed in November 1890 as a producer at a total depth of 662 ft, with an initial production of 200 gallons per day. The decision to drill was taken by the Directors of the AR&T Co. in 1888 under the direction of Mr. W L Lake, an employee of the company and an oil enthusiast.

Uphill and Downhill (1890 – 1920)
After the successful completion of the first well, Digboi Well No-2 was started in February 1891 in the same area, only to be abandoned as dry at 720 ft. The drilling activities of AR&T progressed satisfactorily with 11 wells yielding oil in 1894. A new firm - the Assam Oil Company (AOC), led by the same Chairman, Lord Ribblesdale - was promoted in 1899 to take over the petroleum interests of AR&T, including the Digboi and Makum concessions.

The AOC inherited 14 producing wells, with a total production of 50 barrels of oil per day. Almost immediately on inception, the company expanded the concessional area of the field by purchasing the rights of the Assam Oil Syndicate. In 1912 the rotary system was introduced, Well 47 being the first well to be drilled by this method.

Production almost trebled from 43 bpd in 1901 to 120 bpd in 1902, rising steadily to 247 bpd in 1911, and reaching a maximum of 435 bpd in 1917. By 1920, the AOC had completed 80 wells with a total average production of 350 bpd.

Aftermath of Success (1953 – 1959)
The Nahorkatiya oilfield was discovered in 1953. However, by 1956 only 16 wells had been drilled, and evidence suggested subsurface faults which could have acted either as barriers or conduits to oil movement. Despite this meagre evidence, the AOC announced in September 1956 that proved and probable reserves in the Nahorkatiya area were sufficient to plan a production target of nearly 2.5 million tons of oil per year with 45 million cubic feet of gas per day. On the basis of this assurance, fortified later in the year by new discoveries at Hugrijan and Moran, a public sector refinery was initiated in 1959 at Guwahati with help from Romania. It was commissioned in 1962.

The success of Nahorkatiya Well No-1 set in motion a series of activities. The Burma Oil Company signed a Promotion Agreement with the Government of India (GoI) in January 1958 to form a company - Oil India Private Limited (OIL) - to take over the management of the AOC-discovered fields of Nahorkatiya and Moran. OIL was incorporated on 18 February 1959, with two-thirds of the shares held by BOC and the rest by GOI. The Agreement assured Burmah Oil a dividend of 10% and Digboi Refinery 1.3 million barrels of oil per year. Mr W P G Maclachlan, a key player in the negotiation, became the first Chairman of OIL.

Growth, dynamism, adaptability and technological awareness have marked the activities of OIL from 1959 till today.