Optimisation of the Coal Seam Gas Predrainage Design Process

This project focused on improving the effectiveness and efficiency of gas predrainage programs to be employed in the underground coal industry. It covered a description of fundamental coal seam and gas reservoir parameters as they relate to coal seam gas predrainage and provides a depiction of the availability of gas reservoir data and its application, the current status of gas predrainage design, management and performance.

It delivered a set of gas predrainage design principles that provide a systematic approach to meeting the gas predrainage challenges of low permeability coal, increased coal production rates and greenhouse gas mitigation strategies.

Key to the process proposed is the regular and timely reconciliation of gas drainage performance incorporating the use of reservoir simulators. The reconciliation process permitting:

• Validation of key gas reservoir parameters;
• An update of the mines' gas reservoir characterisation;
• The basis of detailed predrainage plans for the next two years and less detailed plans for the subsequent three years;
• Establishment of predefined targets and deliverables to track the detailed two-year plans against;
• The development of performance indicators that provide the earliest possible indication of underperforming gas predrainage sites.