Drilling And Work Over Updated Date:15/04/2015


OIL currently owns and operates 13 drilling rigs and 14 work-over rigs, besides charter hiring drilling rigs based on operational requirement.

Over 1,000 wells covering over 3.5 million metres, varying in depth from 1,000 – 5,000 metres, have been drilled in various surface and sub-surface environments, including high underground pressures and temperature conditions.

To minimise land acquisition time, OIL has resorted to cluster well drilling to develop its oil and gas fields, which has resulted in protection of green belts surrounding OIL's operational areas.

OIL’s all round excellence in performance is attributed in part to efficient well drilling by the rig building team and proper maintenance of equipment at the company's well-equipped Workshop, which has achieved a peak performance level of over 20,000 m/rig year.

Wireline Logging Services
The process of recording formation parameters against depth for locating reservoirs, their contents and the ability to produce oil, gas or water after interpretation is known as ‘Well Logging’.

OIL’s Well Logging Department (WLD) was set up in 1978 under the directive of the Ministry of Petroleum & Chemicals, to develop self reliance and save foreign exchange being paid to service contractors. This in-house setup, equipped with basic logging equipment, started its logging operations from 1979 by recording a Cement Bond Log (CBL) in Well Jorajan # 12.

The WLD now provides around 75% of OIL’s total logging requirements. The balance 25% is supplemented by service contractors since the WLD has not invested in specialised logging equipment, which is extremely expensive and not cost-effective. Log interpretation, which was earlier outsourced, is now executed by OIL’s personnel. The WLD uses RS6000 workstation and software ‘ULTRA’, procured from Halliburton Energy Services, USA for log interpretation.

The WLD has recorded continuous awards as the best engineering installation in OIL’s internal safety competitions from 1994 till date, besides a continuous accident free record for several years. The WLD won the first prizes in the North-eastern Oil Mines Safety Competition as the Best Engineering Installation and for the Best Safety Performance.

The WLD has constantly stretched its manpower and equipment to their limits to serve OIL’s internal projects. In the onshore Bay Exploration Project at Orissa, it provided the entire logging services for 4 wells in 1987-88. Similarly, in the Rajasthan Project in 1988, the WLD provided logging services for the first well, followed by 3 drilling and 4 work-over wells at Kumchai in Arunachal Pradesh in 1992-93 and in Simen Chapori # 1 under BVEP in 2002. The WLD is also providing Cased Hole logging and perforating services to the Rajasthan Project.

The WLD currently provides self-designed, essential logging services as desired by the management. However, specialised logging services such as those for offshore, horizontal and multilateral wells will be outsourced in the future as well.