The Development, Testing, and Successful Application of Arrangement 2 Seals for Co 2 Pipelines

The use of CO2 for Enhanced Oil Recovery (EOR) has been around since the early 70’s and was developed to enable oil extraction from declining fields. The process involves injecting CO2 from either natural or man-made sources into the ground to free up trapped crude oil that would otherwise not be possible to obtain. This process significantly improves the lifetime production of oil from mature fields. Moving the CO2 from one field to another is accomplished through a series of pipelines and pumps using centrifugal technology. In the early days of this process, pumps were sealed using double pressurized mechanical seals. This particular sealing arrangement was selected because of the very poor lubricating qualities of CO2, the desire for high reliability, and the lack of capability to seal this fluid in the liquid state using a single seal. The downside to this arrangement was the cost and complexity. This paper will focus on new technology that allows for contacting seal faces with minimal seal face temperature rise, minimal wear, and leakage almost an order of magnitude less than non-contacting gas seal technology. Details of the design, testing and successful field application of a contacting type liquid seal using engineered seal face micro features in a CO2 pipeline application are presented.