A Review of Operations at the Twofreds Field CO2 Injection Project

The emphasis of this paper is on what has been accomplished and how it has been accomplished. It is a matter of public record that from the time carbon dioxide was first injected at the tail end of a waterflood operation eleven years ago until now the production from Twofreds Field has increased from less than 180 bopd, to over 920 bopd, with the associated recovery of over 2.5 MMbbls of tertiary oil. The story that hasn't been told is exactly how this has been accomplished; what equipment is involved in the handling, processing, transportation, injection, and gathering of CO2 and the problems encountered throughout the system in dealing with this corrosive and compressible material. With introductory remarks as to the general nature of carbon dioxide, its unusual properties and how they relate to oilfield equipment and handling, this paper addresses equipment design, operation and maintenance from the source through the processing plant, through compressors and down the line, through injection facilities into the reservoir and finally to the recycling stage.