Adnoc studies carbon injection

The Abu Dhabi National Oil Company is testing the use of carbon dioxide to improve production at its oil wells.

The Abu Dhabi National Oil Company (Adnoc) is testing the use of carbon dioxide to improve production at its oil wells, an innovation that will determine whether the Emirate can go ahead with a groundbreaking project to cut emissions from big new industrial projects. The carbon injection plan is an essential part of a multi-billion dollar plan by the Abu Dhabi Future Energy Company, known as Masdar, to reduce the impact of new steel and aluminium projects on the Emirate's growing carbon footprint.

Masdar plans to collect emissions from three locations, compress the gas and pipe it to Adnoc's onshore wells, where it would be pumped underground to increase the flow of crude oil. The gas has been used for years as one method in so-called enhanced oil recovery (EOR) operations in North America, which can markedly increase the amount of oil extracted from underground reservoirs. Now Adnoc has begun tests to see if carbon dioxide would work in the carbonate geology of Abu Dhabi, according to Abdul Munim al Kindy, the general manager of the Abu Dhabi Company for Onshore Oil Operations (ADCO), an Adnoc subsidiary. Adco was now ready to expand the testing to two larger wells, he said, adding a final decision on the technology would be made within a year.

Up until now, EOR has played a minor part in Adnoc's operations, since Abu Dhabi's oil has been relatively easy to extract. But the complicated and costly process of injecting steam, water, chemicals or gas underground to squeeze more oil from the ground would play a growing role in sustaining output and safeguarding Adnoc's strategy to manage its resources conservatively, Mr Kindy said. "If we start now, we can prolong the extraction and utilisation of this wonder fuel," he said of crude oil.

Adnoc could be taking its cue from Oman, which had established itself as a world leader in EOR, said Val Brock, the business development manager for Shell's EOR programme. Oil production peaked in Oman in 2000 at about 1 million barrels a day (bpd). In an effort to keep output levels up for as long as possible, the Sultanate's government has invested in expensive EOR projects and held open the door to private companies to help it produce more.

The country "shows you what, with the right mindset and technology tools, can be done to get more barrels out of the ground," Mr Brock said. "They are really the leading edge for enhanced oil recovery." EOR has slowed production declines and the country now produces a little under 700,000 bpd. At the Marmul field in the north of the country, Shell would start injecting liquid polymers to improve production as soon as next week, Mr Brock said, making it one of the world's first oilfields to employ chemical EOR.

Polymers injection was used in reservoirs that had already been flooded with water by engineers to squeeze out more oil, Mr Brock said. The polymers dissolve in the water and make the liquid thicker, further increasing the pressure of the well and allowing engineers to manipulate which parts of the underground rock are squeezed the tightest. Besides chemical EOR, Shell had also injected steam into Oman's wells to heat the oil and improve flow, and had injected gas into wells to increase pressure, he said.

Depending on the geology of the reservoir, EOR could increase the amount of oil recovered from the ground an average of 10 to 20 per cent. [e-mail]