Todd Energy

Hydraulic fracturing is a well established, safe means of increasing the flow of natural gas from rock formations. Todd Energy uses this technology at its Mangahewa field.

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Hydraulic fracturing is a process used throughout the world to access natural gas and oil reservoirs that would otherwise be uneconomic or technically impossible to recover. It involves pumping fluid under high pressure through deep, heavily encased wells into ‘tight’ (low permeable) oil and gas bearing rock formations. The process produces fine fissures in the target rock. When the pressure is released ‘proppant’ (sand or ceramic beads) remains in the fissures to prop them open and provide pathways for the trapped natural gas and oil to flow up the well to the surface.

New Zealand has a robust regulatory framework in place to ensure hydraulic fracturing operations meet appropriately high safety and environmental standards. The technology has been used safely and successfully in New Zealand for over 20 years and has become the standard treatment for maximising the efficiency of deep gas wells in Taranaki. Up until mid-2011, a total of 65 treatments had been undertaken in 39 onshore Taranaki wells.

Todd Energy uses low volume conventional hydraulic fracturing mainly in the Mangahewa field near Tikorangi to access natural gas trapped in tight sandstone at depths of three to four thousand metres. The target formations and fractures are separated from freshwater aquifers by at least 2,500 metres of impermeable rock. Todd Energy performs these operations under New Zealand regulation and at international industry best practice. Todd Energy has had no incidents of fresh groundwater contamination.

The benefits to New Zealand of hydraulic fracturing are:

• enhanced well productivity, enabling currently uneconomic wells to be brought into production
• an increase in accessible natural gas reserves, with increased energy security and reduced dependence on imported hydrocarbons
• a reduction in the number of wells needed, resulting in a smaller surface ‘footprint’ and reduced risks and costs
• a very small ‘footprint’ on the land. Unlike coal, hydro and wind energy, hydraulic fracturing does not involve large scale landscape disruption. In 2011, Todd Energy’s Mangahewa field alone produced almost as much energy as 90% of New Zealand’s wind turbines combined, and
• increased returns to government through royalty and tax payments.