Conceptualisation and modelling of geological fault zones: New insights from teaming-up environmental tracers and geophysics

Coal seam and shale gas development in Australia worth trillions of dollars are being proven. Groundwater plays a pivotal role in those developments because it is required for stimulation and/or is produced to release the gas. As water resources are limited in Australia, this can lead to conflict with other users. To strengthen Australia’s capacity for making decisions on developments, confidence in groundwater impact assessment models must improve. Fault zones can impact on the efficiency of dewatering, provide pathways for loss of stimulation fluid, and establish a connectivity between geological formations. Needless to say characterising hydrogeological connectivity is a long-standing challenge. This symposium aims to develop a novel framework for fault zone characterization and modelling by fusing geophysics, structural geology, environmental tracers and modelling.

Pricing

  • Free

Event date: 18Sep 2018

Tuesday 18 - Wednesday 19 Sep 2018

Serafino

39 Kangarilla Road, McLaren Vale SA

More information

Scientific Challenges

Understanding the influence of geological fault zones on groundwater flow has been a long standing hydrogeological challenge. On the one hand faults can be a barrier to horizontal groundwater flow, effectively leading to compartmentalisation of groundwater systems, while at the same time faults may act as vertical conduits allowing deep fluids and dissolved chemicals to emanate at the surface. This way faults may provide connected pathways for fluid exchange between deep reservoirs and shallower groundwater systems.

Fault zone investigations based on a joint tracer-geophysics analysis are rare. These studies provide improved means of constraining plausible fault conceptualisations for subsequent flow modelling. This symposium aims to identify novel ways to unlock information from combined analysis of large-scale and deep-reaching geophysical measurements and noble gas tracers such as helium to improve fault zone characterization and hydrogeological modelling.

Symposium scope

A two-day symposium is planned for 18-19 September 2018 in McLaren Vale, near Adelaide. Four themes will be explored via presentations by invited international and national experts. Topics will include:

  • Hydrogeological challenges in unlocking unconventional gas reserves in Australia
  • Noble gas and other environmental tracers for deep fluid flow characterisation
  • Geophysical characterisation of fault and fracture networks
  • Data fusion and modelling of fault zones.

Early career Australian scientists will be invited to present their work at the symposium and to interact with experts. Travel and accommodation for guest speakers and early-career scientists will be provided.

The new, fully automated noble gas facility of CSIRO at the Waite Campus (Adelaide, South Australia) The new, fully automated noble gas facility of CSIRO at the Waite Campus (Adelaide, South Australia) measures all noble gases (He, Ne, Ar, Kr, Xe) in water samples with any amount of helium (old groundwater) and significant contaminants (e.g. CH4 from coal seam gas). It is the only such facility in the Southern Hemisphere

Invited speakers

Johanna Lippmann-Piepke (BGR). Pore water, fluid inclusion and fracture fluids – noble gas studies constrain dynamics of fluid reservoirs

Jonathan Caine (USGS): Characterisation of fractured and faulted bedrock aquifers using outcrop data and numerical modelling

Henning Prommer (CSIRO). Combining tracers and numerical models of groundwater flow

Rolf Kipfer (EAWAG). Continuous field-based noble gas measurements: Applications to understand deep fluid flow behaviour

Daniel Faulkner (University of Liverpool). Physical properties of fault zones.

Alignment with new CSIRO activities

Integration of near surface geophysical data and noble gas tracers to conceptualise fault hydrodynamics (Mallants et al. 2017)Integration of near surface geophysical data and noble gas tracers to conceptualise fault hydrodynamics (Mallants et al. 2017).

Robust and at-scale assessment for resource development is a key research portfolio for the CSIRO, including via initiatives such as the Gas Industry Social and Environment Research Alliance (GISERA) and Geological and Bioregional Assessment Program being implemented for tight and shale gas.

CSIRO has recently invested in new capability to study fluid flow in deeper geological systems. With an investment of AU$ 2.5M, CSIRO's Environmental Tracer Laboratory has been developing new instrumentation and expertise that will allow for the first time in Australia to measure all stable noble gases in water samples.

In partnership with the University of Adelaide, CSIRO is also developing new facilities to collect and measure radioactive noble gases (85Kr, 39Ar and 81Kr), including via the first ATTA system in the Southern Hemisphere. Noble gases are among the most versatile tracers to evaluate deep fluid flow but have seen limited use to date in Australia due to a lack of facilities and expertise.

CSIRO has also invested into the development of advanced geophysical evaluations via its Deep Earth Imaging (DEI) Future Science Platform. The Land and Water involvement in the DEI initiative seeks to greatly improve our ability to infer structural geological features that may impact on groundwater flow.

Science areas: Environment

Event type: Exhibition or workshop