Case Study 1
PRO-DRILL SONIC INNOVATION CHRISTCHURCH EARTHQUAKE
Over 275,000 meters of Sonic drilling delivered with 100% core recovery and operating costs dropping by 75%
Importantly we now operate Sonic Rigs with dual head and capable of performing Sonic, CPT and Traditional Rotary drilling. Complemented by State of the art Specialist Rotary Drilling systems.
The 2011 earthquake in Christchurch was a powerful natural event that severely damaged New Zealand’s second-largest city, killing 185 people. A national state of emergency was in force until April 30, 2011. After that day the city became the focus of the biggest geo technical investigation programme in the world. Pro-Drill arrived in a devastated Christchurch.
The scope of drilling was daunting,’ Russell Sherwin, owner of Pro-Drill, says. The company brought three rotary rigs, all set up on HO triple-tube coring systems. The region’s geology contains sands, silts and gravel; outwash from the Southern Alps some 100km to the west. There is a static water level of less than one metre. After the first month’s drilling, the company came to the conclusion that it had to find a better way of coring. The mud rotary HQ had an average of 40% recovery. Average daily production was 15m a day per drilling rig. Due to the abrasive nature of the formations, it was calculated that the entire drill string would need replacing every three months.
Sherwin spent the next six months researching sonic options, and in November 2011, Pro-Drill purchased an Eijkelkamp SonicSampDrill rig, which had only been on the market for 12 hours.
More rigs followed, including a nearly new CompactRotoSonic XL, and Pro-Drill also commissioned the building of a new CompactRotoSonic XL from the Netherlands. The new drilling rig was transported by air to New Zealand.
The various activities to identify and perform soil stabilisation methods are diverse. Traditionally several machines are needed, making this operation complicated and expensive. The PRO-DRILL Dual head Fraste Eijkelkamp Multi Purpose SonicSampDrill drilling rigs are fully thought through and developed, making them highly versatile. From (sonic) CPT testing, undisturbed soil sampling to soil injection, all can be performed with one rig; eliminating the need for multiple rigs on site will result in significant improvements in core recovery to 100% and immense cost savings to our Clients with costs dropping by 75%.
By April 2012, Pro-Drill had four Eijkelkamp SonicSampDrill rigs operating in Christchurch. A fifth CompactRotoSonic head sat in a crate as standby. Each rig came with on-site training to certify the driller.
In an average eight-hour day, Pro-Drill managed to sample 40m, with standard penetration tests every 1.5m. A record day on one rig was 76m.