SPECIALISED AIRCORE INVESTIGATION
We have developed a large diameter Aircore system that allows for accurate sampling in unconsolidated and paleo channel formations. The system was first designed by our Director, Mick Bonacchi, during his time as Drilling Supervisor to the Water Authority. The need for a quick, accurate and cost effective method for identifying prospective production bore locations in the Gascoyne during the 1980’s resulted in Commonwealth R&D funds being made available to the Drilling and Testing group. From this initial funding, Mick was able to design and have built the first Aircore system of its kind which was trialed and used successfully during the early 1990’s.
Since starting Austral Drilling Services in 1995, Mick has re-designed and refined the system to what we use today and has proven that it is the most effective Aircore system of its kind. It has proven immensely popular in ground water exploration projects where the investigation holes are completed as 50mm ID monitoring wells where the casing is placed through the inner tube before the drill pipe is withdrawn ensuring the completed casing and screens are set to the exact design depths.
Casing Advanced Drilling
We operate dual rotary casing advancement systems in 8” to 14” diameters (other sizes on request) that are used to case through difficult cavernous and lost circulation formations. This system is particularly suited to drilling formations such as the channel iron deposits and river alluvials that cannot be drilled with standard air and mud methods.
The casing shoe is welded to the casing. The pilot bit and ring bit are locked together by the bayonet coupling. Together they drill a hole large enough to allow the casing to be pulled into the hole. The pilot bit and ring bit rotate with the drill string while the casing shoe and casing do not rotate. After completing the hole, the pilot bit is unlocked by a slight reverse rotation of the drill string. The drill string and pilot bit are then retrieved through the casing.
We specialise in large diameter, artesian water bores and are arguably the most experienced high artesian pressure drilling company in Western Australia. We have carried out some of the most difficult pressurised aquifer bore completions ever undertaken in WA, with heads of 50m and flows exceeding 260 L/sec. We have 4 class 3 artesian drillers in our ranks with more than 100 years of combined expertise and have drilled dozens of artesian bores in the West Canning and Carnarvon Basins. These environments contain extremely complex challenges and the possibility of a lost bore is very real. A lost bore in these situations could mean a very difficult and costly recovery operation to bring the bore back under control and repair damage to environment and property.
We have developed unique drilling methods for combatting the wide range of issues presented by this type of work. From thixotropic mud systems for lost circulation to placement of balanced grout tables as temporary protection of an aquifer during casing grouting operations. Artesian wells often have both lost circulation and flowing conditions from different zones within a well, we have refined a balanced mud system that addresses both issues and allows us to drill deeper and bring in wells that produce far more water than other contractors using standard methods.
This system works by removing the cutting from the drill mud, re-circulating the mud, cleaning and processing it for use back down the bore hole. Cuttings are discarded into skip bins for approved disposals. The benefits of this system include minimised ground disturbance in sensitive areas, smaller footprint, decreased water usage during drilling, faster site rehabilitation, faster setup times and cost savings in mud.
Test Pumping & Bore Management
We undertake testing of new or existing bores, using a wide range of pumps and measuring equipment capable of supplies up to 50 litres/second. Appropriate pumping rates for bores and long term sustainable bore yields can be accurately determined. The effects of pumping can be predicted using our computer modelling packages, these predictions can be integrated into management plans and practices. Down-hole video is available to determine the current status of an existing bore or to assist in bore maintenance.
We have Hydrogeologists on call for the design of water drilling programs, analysis of raw data and Groundwater modelling.
Our Hydrogeological team have successfully and safely carried out projects in locations throughout Western Australia including some of the harshest and most difficult landscapes the state can offer. We can manage and carry out:
- Geological Target Definition
- Geophysical Surveying
- Drilling and Test Pumping
- Resource Estimation
- Borefield Design Consultation
- Borefield Operating Strategies
Down Hole Camera Survey (Video Log)
We own high quality specially built CCTV cameras ready for bore survey inspections.
The cameras provide down and side view with full 360˚ rotating 40mm camera.
Down-hole survey can be crucial to the redevelopment and rescue of a bore. The use of a down-hole camera prior to commencing any rehabilitation work enables us to formulate a plan based on the video log by targeting the exact area in most need of attention. A before and after video log, enables the client to see a visual record of the effects of the work that has been carried out. This type of log can also be used to verify newly constructed bores have been completed to the desired standard and specification required.