Energy and Earth Resources
Isotopic analysis of hydrocarbons is helping to build a comprehensive body of geochemical information about New Zealand’s oil and gas resources and mineral deposits
The molecules that make up oil and gas include carbon and hydrogen – elements that have a mixture of naturally-occurring isotopes. Throughout the process of plant materials transforming into oil and gas over millions of years, the isotopic signature of carbon is conserved and provides valuable information about the origin, age, and depositional environment of the precursor plant material.
In a joint government-GNS Science initiative to help oil and gas exploration and move New Zealand closer to self-sufficiency in liquid fuels, our expertise in the isotopic analysis of hydrocarbons is helping to build a comprehensive body of geochemical information about New Zealand’s oil and gas resources. We analysed over a hundred oil, gas and source rocks samples from eight sedimentary basins of New Zealand, including the Taranaki, Great South and East Coast basins. Comparison of the isotopic fingerprints of these samples can indicate a common source or provide valuable information about the pathways the fluids may have travelled to reach the host reservoirs.
This level of isotopic fingerprinting is relatively new to the petroleum exploration industry in New Zealand, and complements geo-chemical bio-marker analysis to determine source, age and deposition of organic material. Isotopic fingerprinting elucidates subtle differences between gas and oil families to reveal timing and generation-specific source contribution to oil and gas, supporting and defining the information derived from bio-markers.
A three-year project being led by GNS Science is using nanotechnology processes to provide a breakthrough in electricity production and greatly enhance thermal and electrical conductivity of power generators.
Most forms of energy generation produce ‘waste heat’ which could potentially be recovered and converted into electrical energy; however this is not commercially viable with present technology.
A three-year project being led by GNS Science, in collaboration with other researchers from New Zealand and America, is using nanotechnology processes to provide a breakthrough where conventional technology has failed. The project will trial a wafer-thin layer of space-age material embedded onto the surface of generator components to greatly enhance thermal and electrical conductivity.
A crucial ingredient in the project is the use of ion-beam technology where atoms are implanted into the surface of materials to form a strongly bonded layer several hundred atoms thick. This creates superior electrical and physical properties, and there is no alternative technology to achieve the same outcome. By the end of three years, the scientists hope to test a thermoelectric power generator concept so industry can then develop it further and commercialise it.
“We see this project as a natural extension of our work which includes over a decade of developing nanostructured materials and semiconducting materials,” project leader Dr John V Kennedy, of GNS Science said.
There are many potential applications for this new technology, ranging from lawn mowers and outboard motors to large industrial plants and power stations. All of these applications will benefit from increased energy conversion efficiencies, lower energy waste and reduced greenhouse gas emissions from energy production.
Using isotope analysis to assist the management of hydro-dam security and geothermal resources
The long-term security of hydro dams depends on the effective control of seepage from the reservoir through the foundations and abutments. Seepage paths are a complex function of dam design and construction, local geology and modification of pre-existing groundwater conditions.
Isotope signatures deliver reliable insights into possible leaks in dam foundations. Using water dating (tritium), stable isotope analysis (oxygen and deuterium) and temperature techniques, we can quickly distinguish leakages from surrounding groundwater and from the reservoir. That’s invaluable knowledge for prompt and successful action, such as grouting design and verification programmes.
Our experts also use natural tracers, including tritium, in regular monitoring of geothermal production fields. In reservoirs used for power generation, tritium can indicate any penetration of young surface waters or injection fluids. Tritium analysis can also be used to determine the circulation time for high temperature geothermal waters. This knowledge assists in effective geothermal reservoir management.
For more information, please contact:
- Joe Manning, Head of Department, Materials and Air, GNS Science
- Mike Sim, Head of Department, Isotope Biogeoscience, GNS Science
- Stew Cameron, Head of Department, Hydrogeology, GNS Science