Basin resource management frameworks: 4D geoscience information, modelling and knowledge systems to allow the informed assessment and management of earth resources

摘要

In the 21st century, sedimentary basins are moving rapidly from single-use zones - such as petroleum - to highly complex, vertically and laterally stratified, multiple-use zones. Several independent industry and community sectors, such as petroleum, water, geological carbon storage, coal seam methane and geothermal, will be competing for access to, and the use of, limited pore space and the resources within it. These sectors are often in direct conflict, for example geothermal energy production and geological carbon storage (GCS) are almost mutually exclusive. Geothermal is also in competition with the water sector (agriculture, communities etc) for the right-to-produce fluids. This new environment requires an innovative and proactive response from government, one in which the relative value and benefit of a wide variety of known and potential resources can be quantitatively assessed, and thereby managed, for the benefit of the State. This requires the building of robust and high-resolution geoscience information and knowledge systems which support the informed management of basins as multiple use zones, thus enabling the GCS, geothermal, petroleum and water sectors to co-exist and prosper. These basin resource management frameworks must be constructed at a regional-scale to allow assessments to be made of potential impacts and relative values of all relevant earth resources. As part of the Victorian Government's geological carbon storage assessment, GeoScience Victoria's VicGCS initiative has been collating, interpreting and integrating a wide-range of disparate geoscientific data from the onshore and offshore Gippsland Basin, the premier geological carbon storage location in Australia. The data include the distribution and properties of sedimentary horizons and faults (including the construction of basin-scale 3D models), rock property data, fluid compositions (water, hydrocarbons etc) and fluid flow properties, pressure data, reservoir data and extensive investigations of containment, to build highly complex and predictive geoscience models. In addition to providing a quantitative and agreed means of assessing and managing earth resources, the models provide data and ideas which dramatically improve the understanding of the current and undiscovered resource inventory. The basin resource management framework for the Gippsland Basin provides government with the management tool-kit and knowledge necessary to develop an informed strategy to manage the basin's pore space and other resources, in order to maximize the benefit from each resource and to minimize potential conflicts between competing resource sectors. This knowledge will also facilitate the gazettal of GCS acreage, GCS roll-out, and provide the basis for monitoring the basin through the GCS life-cycle. For example, through sufficient understanding of fluid migration in the basin, it is possible to monitor plumes of injected CO_2, as well as the far-field effects of the injected plumes (e.g. formation pressure and the water table) across the entire basin. The regional or basinscale knowledge required by government complements the focused and much more site-specific studies undertaken by industry.