The Bahrain Field was first discovered in 1932 and has been operational ever since. Mauddud, a lower-cretaceous, oil-wet carbonate reservoir, with crude of 330-API gravity and about 110 feet thick, is the field’s most prolific reservoir and was selected for crestal gas injection starting in 1938.

Gas injection in Mauddud is still continuing, leading to a recovery of about 35 per cent of original oil in place, with a growing gas cap at the crest. The remaining oil saturation in the crest varies from 25-40 per cent in different areas of the reservoir, leaving a large volume of oil behind. In order to recover this, Tatweer Petroleum, a joint venture of the local Nogaholding, the US’ Occidental Petroleum and Abu-Dhabi’s Mubadala Petroleum, planned a new recovery process called the Light Oil Steam Flood.

The method involves injecting steam into a reservoir, which then heats residual oil to the point of vaporisation. Once vaporised, the crude is transported to a well, from where it can be extracted.

A pilot project was implemented in November 2012, after studies confirmed significant reduction in oil saturation after steam was flooded through the Mauddud samples. Reservoir simulation studies were also conducted to decide the pattern size and configuration of the pilot and steam injection rates.

The Light Oil Steam Flood scheme is the first of its kind in the world and could have broad applications if successful.