The Abu Dhabi National Oil Company (Adnoc) is planning to launch four pilot projects to test new enhanced oil recovery (EOR) methodologies, as part of its larger strategy to raise oil production from EOR techniques.

“Starting 2021, we (Adnoc) plan to commission four EOR pilots aiming basically at introducing new EOR concepts that have been customised or designed to suit our reservoir heterogeneity. When we talk about reservoir heterogeneity, in Abu Dhabi we have complex carbonate reservoirs, huge heterogeneity and harsh conditions. So on that basis we have designed new EOR concepts,” Ayesha al-Marzouqi, manager at the enhanced oil recovery department of Adnoc, revealed.

In no particular order of start date or priority, the first pilot will see simultaneous injection of polymer and water in the Asab field; the second pilot will be an experiment of simultaneous injection of polymers and gas in the Bab field; the third pilot will be simultaneous injection of water and gas at the Buhaisa field; while the last one will be water alternating gas at another reservoir in the Asab field.

“The current expectation is that we are going to evaluate the results of those pilots in the middle of the next decade, and then we are going to decide on the full field development of those four concepts. The expansion strategy is based on a phased development,” Al-Marzouqi told MEED, adding that the four pilot projects would be “industry firsts” for carbonate and sandstone reservoirs.

Adnoc currently produces about 3 million barrels a day (b/d), of which only about 200,000 b/d or about 7 per cent comes from EOR, a recovery figure that the UAE oil giant wants to eventually increase to 20 per cent, as part of its Vision 2030 objectives.

“At Adnoc we are blessed with reservoirs in which we can achieve up to 50 per cent of oil production using conventional techniques (compared to the global average of 30 per cent). We of course need to prepare for the future,” Al-Marzouqi said.

“Talking about EOR, we have designed a well-defined roadmap where we basically pursue, or ensure that we sustain the current production level to begin with. Then of course we proceed towards achieving the Adnoc target of achieving 70 per cent ultimate recovery by the end of the field life,” she added.

The Adnoc official further said that the company is looking to develop further EOR technologies beyond the four pilot projects, with techniques such as acid gas injection, low salinity water injection and foam injection.

Al-Marzouqi clarified that Adnoc has no plans of engaging in solar-powered thermal EOR, like its Gulf peer Petroleum Development Oman in the Sultanate, due to Adnoc having light oil reserves. The Abu Dhabi oil major intends to continue performing gas- and chemical-based EOR, “unless we discover a new reservoir with heavy oil,” she said.