ABSTRACT: Coal bed methane enhancement with CO₂ sequestration - worldwide potential

Gale, John Joseph, and Paul Freund, (1) IEA Greenhouse Gas R&D Programme, Cheltenham, Glos, United Kingdom

A new coal bed methane production technology has the added attraction of tackling greenhouse gas emissions. Injection of carbon dioxide, an important anthropogenic greenhouse gas, into deep coal seams can enhance methane recovery, whilst simultaneously locking up the carbon dioxide in the coal measure. Providing the coal is never mined, the carbon dioxide would be sequestered for many years, and thereby help to avoid climate change.

Initial results from the world's first carbon dioxide-enhanced coalbed methane (CO₂-ECBM) pilot in the south-western United States show this new technology to be technically and economically feasible. Since 1996, over 57 million m³ (2 Bcf) of CO₂ has been sequestered in Cretaceous Fruitland coal seams located in the northern San Juan Basin. Based on current costs and performance, CO₂-ECBM may be profitable in the San Juan and nearby basins at prevailing wellhead natural gas prices of US$0.06 to $0.07/m³ ($1.75 to $2.00/Mcf), representing an estimated 8.5 Gt of CO₂ sequestration potential.

The technology for implementing and operating CO₂-ECBM recovery is based on demonstrated oilfield technology, although further refinements are needed. Apart from the San Juan basin, coal basins in Australia, Russia, China, India, Indonesia, Canada and other countries also have large CO₂-ECBM potential, estimated at 150 Gt CO₂. Analysis of representative CO₂-ECBM projects indicates that 5 to 15 Gt of carbon dioxide could conceivably be sequestered at a net profit, while about 60 Gt of sequestration capacity may be available at moderate costs of under $50/t CO₂.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia