CO2 management at ExxonMobil’s LaBarge field, Wyoming, USA

Abstract

Production of natural gas from the LaBarge field in southwest Wyoming began in 1986. This gas contains high concentrations of carbon dioxide (CO2), and from the very beginning, ExxonMobil has successfully implemented several technologies and approaches to effectively manage the substantial volumes of CO2 associated with its production. Many of the technologies and approaches used for managing CO2 at LaBarge are examples of technologies and approaches being proposed for use in carbon capture and storage (CCS) by other industries. The Shute Creek Treating Facility (SCTF) processes the gas produced from the LaBarge field. The SCTF handles the lowest hydrocarbon content natural gas commercially produced in the world. The gas composition entering Shute Creek is 65% CO2, 21% methane, 7% nitrogen, 5% hydrogen sulfide (H2S) and 0.6% helium. The SCTF separates CO2, methane, and helium for sale and removes hydrogen sulfide for disposal. Most of the CO2 captured at Shute Creek is used for enhanced oil recovery (EOR). EOR is consistently cited as one of the most viable early opportunities for large scale implementation of CCS. ExxonMobil’s LaBarge operation is the largest deployment of this approach to CCS in the world today. Currently ExxonMobil provides 4 to 5 million tonnes per year of CO2 for EOR. Ongoing facility expansion will increase this capacity to over 7 million tonnes per year in 2010. A concentrated acid gas stream of about 60% hydrogen sulfide and 40% CO2 is injected into a carefully selected section of the same reservoir from which it was produced, safely disposing of the hydrogen sulfide along with approximately 400,000 tonnes of CO2 per year. Other technologies and approaches that have reduced CO2 emissions include the ExxonMobil patented low BTU fuel co-generation system that substantially reduces CO2 emissions when compared to emissions from purchased power. Cumulatively, through the application of these technologies at LaBarge, ExxonMobil will have the capacity to capture and manage over 75% of the CO2 produced from the LaBarge field. Additionally, new technologies are being developed that may provide additional reductions in emissions, either at this site or at others with similarly challenged production streams. Construction of a commercial demonstration facility for ExxonMobil’s Controlled Freeze ZoneTM (CFZ) gas treatment technology has been completed at Shute Creek and operations are about to begin. The CFZTM technology allows the single step separation of CO2 and other contaminants from a natural gas stream without the use of solvents or absorbents. Its successful commercial demonstration would enable the development of increasingly sour gas resources around the world by substantially reducing gas treatment and geo-sequestration costs from these sources.