Allison Unit

Project Overview

The Coal-Seq project is investigating the feasibility of carbon dioxide (CO2) sequestration in deep, unmineable coal seams by performing detailed reservoir studies of two enhanced coalbed methane (ECBM) recovery field projects in the San Juan basin. One of the sites is the Allison Unit, operated by Burlington Resources, into which CO2 is being injected. The purposes of the field studies are to understand the reservoir mechanisms of CO2 injection into coal seams, demonstrate the practical effectiveness of the ECBM and sequestration processes, demonstrate an engineering capability to model them, and to evaluate sequestration economics. The Allison Unit is located in the northern New Mexico portion of the prolific San Juan basin.

The field originally began production in July 1989, and CO2 injection operations for ECBM purposes commenced in April, 1995, six years after beginning production. CO2 injection was suspended in August, 2001, to evaluate the results of the pilot. In this study, a detailed reservoir characterization of the field was developed, the field history was matched using the COMET2 reservoir simulator, and future field performance was forecast under various operating conditions. CO2 is delivered to the site from out of state via a pipeline. A total of 181 million m3 (6.4 Bcf) of CO2 was injected into the Allison Unit over a period of six years, of which 25 % is forecast to be ultimately produced back, resulting in a net storage volume of 277,000 t CO2.

Project Type

Storage

Location

San Juan Basin, New Mexico, U.S.A

Type of CO₂ Storage Operation

Enhanced Coal Bed Methane

Major Stakeholders