Groundwater management: how centralisers can help

P1010649As the driest inhabited continent on earth, rapid depletion of Australia’s groundwater resources is becoming an important issue for Australia’s economy and wellbeing. As the mining and drilling industries are major users of this valuable asset, each has an important role to play in the protection and management of the country’s finite supply.  In this article we take a closer look at how the smallest of equipment can make a big difference.  

Groundwater plays a major role in supporting Australia’s industry and population. On a national level, groundwater makes up about 20 per cent of Australia’s accessible water resources and up to 30 per cent of Australia’s water consumption in particular regions.

According to Deloitte’s 2013 report on the Economic Value of Groundwater in Australia, average annual groundwater use is approximately 3,500 GL. Water used for agricultural irrigation is the largest single user group, comprising on average approximately 60 per cent of Australia’s annual groundwater use. Other user groups include mining (12 per cent), manufacturing and other industries (17 per cent), household water supply (5 per cent), and as an input into potable water supply networks (9 per cent).

Current problems

The challenge in utilising groundwater is that its usefulness is commonly limited by the quality of water, as well as its location and rate at which it can be abstracted from the ground.

As industry and population continue to expand, overuse of groundwater reserves is leading to high salinity levels, making it unusable for agricultural or drinking purposes.  Poor management of the resource during mining or drilling applications is also leading to an increase in pollution and contamination.

Mining and drilling

Mandatory requirements set out by the National Uniform Drillers Licensing Committee (NUDLC) provide industry with Minimum Construction Requirements for Water Bores in Australia, and give contractors within the industry clear guidelines to water safety, management and best practices.

According to the NUDLC the following points relate to spacer and centraliser considerations:

Casing: When choosing a casing, plastic or steel casings are recommended. For corrosive water, PVC-U, ABS, FRP, or stainless steel casing provides the longest life possible. Centralisers that do not damage plastic or steel casings must be used.

Sealing: In sealing the bore, the casing should be centred in the hole by means of mechanical centralisers. In corrosive water areas, centralisers should be of inert material, or material of a similar grade to the casing to which they will be attached.

Screens: Centralisers should be used on the screen assembly and be constructed of inert material or the same material as the screen.

In the drilling industries including mineral, coal and coal seam gas extraction, there are a number of ways in which contractors can play a key role in groundwater protection and management.

  • By preferencing non-corrosive construction materials where possible, and adopting effective grouting methods to ensure that screens do not come in contact with different aquifers, inter-aquifer connection and the potential for water contamination transfer between aquifer’s can be prevented.  
  • By providing a long-lasting seal to a tapped aquifer through the use of inert casing, flanges and valves, to prevent contamination as well as aquifer depressurisation.
  • By reducing the potential for cross-contamination of aquifers and sites, particularly in relation to inter-aquifer connection due to corrosion of steel casings, and the clogging of screens and pumping equipment.

How kwik-ZIP can help

kwik-ZIP offers a diverse range of spacers for both the civil and pipeline industries as well centralisers for water, oil and gas wells.

Being made entirely from high-grade thermoplastic, these inert spacers and centralisers do not damage plastic casings and do not corrode in both water and chemical surroundings. The can be used on both plastic casings as well as steel casings, providing a truly versatile solution.

Because of this, kwik-ZIP helps contractors comply with best practice management of groundwater during drilling applications, and adhere to each of the above NUDLC requirements.

Also adhering to the latest Water Services Association of Australia Casing Spacer Standard WSA PS – 324, kwik-ZIP spacers and centralisers have made them the preferred spacing solution across the Australian mining and drilling industry.