Unconventional Resources: The Next Generation. Assessing Coal to Liquids, Oil Shale, Underground Coal Gasification, Microbial Coal Conversion and Other Technologies within the SPE-PRMS.

Abstract

Abstract As unconventional resources such as Shale Gas and Coal Bed Methane become mainstream, many companies are looking towards the next generation of resource types. Coal to Liquids, Oil Shale, Underground Coal Gasification and Microbial Coal Conversion are examples of resource types that are being assessed and in the early stages of commercial exploitation within the Asia Pacific region. How can companies looking to exploit such resources assess their projects within a common framework? Such projects run the risk of falling between the cracks of petroleum assessment guidelines such as the SPE-PRMS and mining guidelines such as JORC. These resources often do not occur naturally as hydrocarbons. They typically involve a mining, or in-situ, extraction process followed by a direct or indirect upgrading process whose end product is a saleable liquid product such as synthetic crude oil. In some cases, in-situ extraction is possible. Whilst such mining and upgrading processes are clearly included within the SPE-PRMS for such deposits as tar sands and bitumen (which are already naturally occurring hydrocarbons), the situation is less clear when the raw material is not naturally occurring hydrocarbons. Coal to Liquids involves mining the coal/lignite followed by an upgrading process to produce synthetic hydrocarbons. Oil Shale is essentially an immature kerogen-rich source rock which requires artificial maturation to generate hydrocarbons. Various techniques are available, either in-situ or mining followed by an upgrading process at the surface. Underground Coal Gasification is an in-situ process used in non-mined coal seams to generate gases including methane through injection of oxidants and steam to fuel an underground combustion process. Another emerging technology is microbial coal conversion. Although they do not fully satisfy all of the definitions of the SPE-PRMS, the authors believe that the principles of the SPE-PRMS can be used to assess such resources. The project can be evaluated as a whole i.e. from mined raw material through upgrading process to saleable end product. Further clarity and definition within the SPE-PRMS would assist such assessments. Overlap and integration with JORC and other mining codes would also aid understanding and transparency. There are also challenges required during the assessment of such projects. Traditional petroleum industry skills must be supplemented with expertise in mining and product upgrading in order to perform a full analysis. With many companies in the Asia-Pacific region, especially Australia and China, assessing such resources and looking to commercialise them, improvements in their understanding and assessment would be beneficial to all stakeholders.