J&S drilling continues works at Rio Tintos RMA facility in Yarwun QLD. J&S Drilling have been carrying out the Rio Tinto RMA Drilling QLD programs at the since late 2016. The drilling programs to date have consist of Geotech investigations, Monitoring bore drilling & installations, Drilling of potential Class 3 flowing bores and de-watering bores.
J&S carried out 26 geotechnical holes working along side GHD. The hole were drilled with HW advance drilling techniques with SPTs and Push tubes until competent ground was encountered. The HW was then cased off and the boreholes were then HQ cored to the target depth decided by GHD. On completion of the bores, packer testing was carried out to determine how much water the natural fractures would take.
In 2017 a depressurization monitoring bore program was carried out by J&S drilling. J&S drillers hold a class 2 water well license. As these bores had the potential to flow, J&S engaged a class 3 driller to supervise the drilling works. The 4 bores were drilled to depth of around 60m to determine bores flow. Air drilling techniques were used, and the bores were drilled from surface in accordance to the minimum bore construction standards to be setup as a class 3 bore. The 4 bores had surface casing installed with heavy grout mixes pumped around the annulus to prevent the bore from potentially flowing out of control if pressurized ground water encountered. None of the bores flowed in the end and it was a great result for everyone involved in the program.
For the Majority of 2018, J&S drilling have been carrying out drilling for monitoring bores around the RMA and the purposed RMA 2. J&S have been working along side KCB hydrogeology department. Over 50 bores have been drilled in these 2 areas over the past 9 months. The ground conditions prove very testing for the driller and crew. Tubex methods (air casing advance) have typically been used to date to manage the highly fractured siltstone at the surface of the holes. Once competent ground has been encountered J&S revert to conventional open hole hammer method to ascertain water intervals, flows and quality readings for KCB. On completion of drilling J&S drilling utilizes the licensed Class 1 and Class 2 drillers to install monitoring bores in accordance with the minimum standards for drilling and installing bores. The succession rate for these bores is near perfect considering the ground conditions.
J&S remain the preferred drilling contractor for all drilling works at the RMA facility and will continue to present results to the client.