Integrated Technologies to Improve Low-Permeability Coalbed Methane Production Outcomes and Coal Mine Methane Pre-Drainage Efficiency and Emissions Reductions

This paper presents a comprehensive evaluation of emerging technologies designed to enhance coalbed methane (CBM) production, improve coal mine gas pre-drainage for safety, and reduce emissions of coal mine methane (CMM). The integrated framework and workflows combine advanced diagnostic, drilling, and fracturing techniques to address the challenges of developing low-permeability coal seams. Broader applications of Diagnostic Fracture Injection Tests (DFITs) are explored, extending their use beyond conventional stress and reservoir characterisation to include the identification of Pressure-Dependent Leakoff (PDL) and directional permeability through multi-well interference testing. This enables improved stress profiling, drainage pattern assessment, and more informed development planning. In addition, the paper discusses the evolution of indirect hydraulic fracturing and tight radius drilling (TRD) to enhance mine gas pre-drainage and emissions control, supported by innovations in micro-proppant materials and placement strategies to maintain fracture conductivity in coal seams. Field results demonstrate how DFITs and indirect fracturing improved pre-drainage at an underground Bowen Basin mine. Complementing this, the paper reviews the historical use and future potential of Tight Radius Drilling (TRD) and Surface-to-In-Seam (SIS) wells combined with reservoir barriers to further lower CMM emissions. This integrated approach brings together proven, tested, and modelled technologies suited to the unique conditions of the Surat and Bowen Basins and other low-permeability, highly stressed coal reservoirs in the Eastern Hemisphere. The novel contribution lies in presenting these methods as a cohesive workflow for CBM and CMM operators seeking practical, accessible solutions to unlock challenging reserves while enhancing safety and reducing greenhouse gas emissions. Barrier implementation models are also highlighted, indicating the potential for open-cut mines to achieve up to 46% emissions reduction per square kilometre of drainage area, demonstrating substantial environmental benefits alongside production gains.