ABSTRACT: CO₂ injection and sequestration in depleted oil and gas fields and deep coal seams: worldwide potential and costs

In the United States, carbon dioxide is injected commercially on a large scale into many mature oil fields to achieve enhanced oil recovery (EOR). During 1998, a total of 74 active CO₂-EOR projects recovered nearly 200,000 barrels/day of EOR. In the process, an estimated 15 million tonnes of CO₂ was sequestered without emission credit subsidies and at average full-cycle profit of approximately $11/t (@$15/bbl oil price). 20% of injectant is anthropogenic waste CO₂ from natural gas processing plants and fertilizer manufacturing facilities.

Injection and sequestration of CO₂ into deep coal seams is another potential geological sequestration technology. Initial field testing being conducted in the U.S. and Canada, but large-scale commercialization is at least several years away. If a global trading system for CO₂ emissions reductions is established, the economics of EOR and ECBM projects would improve.

This study assessed the global capacity, costs and technical feasibility of sequestering CO₂ in depleted oil and natural gas fields and deep coal seams. Using petroleum production, reserves, and resource data bases recently published by the U.S. Geological Survey, and international coalbed methane project data, a detailed economic model of sequestration was constructed. Capital and operating costs for each province were estimated and the net unit costs for CO₂ sequestration were calculated.

The worldwide CO₂ sequestration capacity of depleted petroleum fields and coal seams was estimated at approximately 1,083 Gt, equivalent to about 150 years of worldwide power plant emissions. In the future, CO₂ sequestration in depleted petroleum fields could become a substantial and profitable new business area for oil & gas companies.

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