State oil giant Saudi Aramco plans to inject carbon dioxide into the world's biggest oilfield by 2012, a year ahead of previous plans, a government official said on Monday.

The giant field Ghawar pumped 5 million barrels per day (bpd) in 2008, more than half of top oil exporter Saudi Arabia's output. The kingdom announced plans last year for a pilot project to pump the climate-warming gas into the field to both improve production and reduce emissions.

This is a major project that will be implemented by Aramco by 2012, said Muhammed al-Sabban, head of the Saudi delegation to UN talks on climate change and a senior economic adviser to the Saudi oil ministry. It is a pilot project that will try to reduce or sequester carbon emissions.

The project would be entirely financed by Aramco, he added.

The kingdom plans to inject 40 million standard cubic feet per day (cfd) of CO2 into the field, and has said this is part of the global push to trap emissions rather than because it needs to enhance oil recovery from the field.

Carbon capture and storage is looked upon favourably by oil producers as they need to inject gas into oilfields anyway to maintain oil pressure. If they can use CO2 instead of natural gas, they can send the natural gas to local grids where it can be used by industry or in power plants.

Aramco is also making efforts to reduce emissions from oil products it makes by upgrading refineries to produce cleaner fuels. The kingdom has said it supports moves to reduce climate change, but registered opposition to schemes that singled out oil's role in global warming while promoting other fuels.

Last month, Sabban told Reuters the United Nations' climate talks are a bigger threat to Saudi Arabia than increased oil supplies from rival producers. [ID:nLDE60N07E]

Sabban reiterated on Monday that the top oil exporter was looking to start exporting power from solar energy by 2020. (Reporting by Asma Alsharif;, writing by Reem Shamseddine; editing by Simon Webb and James Jukwey)