An operator’s coalbed-methane (CBM) -development projects in Queensland, Australia, are designed with a large volume of wells that will need to be drilled and evaluated over the next decade. At present, the cost of logging is forcing the operator to choose between early data coverage vs. restricted logging. To resolve this issue, the operator has embarked on a series of technology trials to investigate various cost-effective formation-evaluation solutions. This paper presents the results of a comparison of state-of-the-art mining logging technology and conventional oil-and-gas logging technology.
The Surat basin is a broad intracratonic downward that covers an area of approximately 300 000 km2 in southeastern Queensland and northeastern New South Wales. The operator’s interests are solely in Queensland. The basin comprises a primarily nonmarine Jurassic succession overlain by a mixed nonmarine and marine Early Cretaceous succession. (For detailed geological information, please see the complete paper.) The operator’s proposed Surat CBM project is located in the eastern part of the basin, in Queensland only, with an area of 22 000 km2.
It is important to use geophysical logs as part of the data-acquisition program, especially during the early development phase. The geophysical logs are used for coal identification, derivation of coal properties, and coal ranking. Current mining logging technology consists of a basic logging suite such as gamma ray, density/photoelectric factor, and neutron and resistivity tools. For advanced logging operations in exploration and appraisal wells, these must be replaced by conventional oil-and-gas logging tools to ensure holistic subsurface characterizations and front-end engineering work for future project-development decision making.
Formation-Evaluation Log-Off Results for Coalbed-Methane-Field Development
26 July 2016