Facts:

These five separate gas processing facilities in the Val Verde area of Texas, USA, capture around 1.3 million tonnes of CO2 annually for use in EOR operations at the Sharon Ridge oilfield. The dehydrated and compressed gas is transported via the Val Verde and CRC pipelines.

The five facilities are the Mitchell, Gray Ranch, Puckett, Pikes Peak and Terrell gas plants. EOR is believed to have been used at the Sharon Ridge field since 1972. The projects were formerly known as Sharon Ridge.

Companies involved include refiner Pennzoil, and Altura - one of the largest oil producers in Texas and industry leader in the EOR operations using CO2 flooding. It also has access to extensive seismic data. Altura E&P was formed by Shell and BP Amoco, and sold to Occidental in 2000. No further details are available.