BP Sharjah pioneering unique oilfield drilling technology to improve ultimate recovery

This technique, says BP, can be used to extend the working life of mature oil and gas fields for several years after they would otherwise be considered depleted. The impact is to improve oil and gas recovery leading to a benefit measured in hundreds of millions of dollars of reserves. But the really smart thing is that this technique can be used on active wells without interrupting existing production.

The global first is based on 'coiled tubing' drilling technology used successfully by BP in Alaska that employs a long straw-like tube rather than conventional 40-foot 'strings'. The BP Sharjah team have combined this technique with specially made drilling assemblies that are powered by environmentally friendly nitrogen mixed with a small amount of water. As it drills horizontally through the limestone structure of the reservoir, the released gas is immediately gathered and sent to market for sale on the same day.

"This is a great example of how BP develops distinctive technologies and applies them directly in our key oil and gas operations around the world," said Dan Borling, BP Sharjah resource manager. "By combining our Alaska expertise in coiled tubing technology with under-balanced drilling techniques, we are able to access otherwise inaccessible gas reserves, selling it to market the same day rather than flaring it, and doing so in an environmentally friendly way."

The project is assisted by BP's Exploitation Division in Sunbury, UK, using advanced computer generated three-dimensional visualisation technology to advise the Sharjah team on the actual locations of the gas reserves. The so-called HIVE (highly immersive visualisation environment) technology projects seismic data in a 3D format to enable BP geophysicists and reservoir experts to simulate a 'walk through' of the reservoir structure, some 12,000 feet below the surface, to optimise well locations.

Following 12 months of feasibility studies the first well was begun in April 2003. The team recently completed its twenty-first well, a feat described by Borling as "fantastic."

Borling estimates that the ground breaking technology is enabling them to liberate millions of barrels of oil, or billions of cubic feet of gas, that would otherwise be inaccessible. BP operates the Sajaa gas field in a partnership with the government of Sharjah.