Core efficiencies

CERTAINTY in core sampling for drilling rig operators is now a reality. Jamie Wade writes

Certainty in core sampling for drilling rig operators is now a reality. Jamie Wade writes.

Core sampling can be a hit and miss affair. However, a Perth-based technology company has developed an award-winning solution that records the amount of core column that has entered the core barrel during coring.

The Core Level Indicator System (CLIS) allows the operator to compare the amount of captured core, against the depth of formation penetrated by the core barrel. If these two parameters do not match, this indicates that core is not entering the barrel and a core sample is not being obtained because either core is being ‘milled’ and/or the core barrel is ‘jammed’.

The key to the technology is a telemetry system that transfers the information to the surface operator in ‘real time’ allowing the coring operator to make an immediate decision to pull the coring assembly if no core is being captured.

Given that coring is an expensive operation, especially in the offshore oil and gas industry with rig rates of around $30,000 per hour, the application of the technology will be highly attractive to oil and gas exploration companies.

Coretrack Limited’s managing director and CEO Nanne van’t Riet, whose company won an Inventor of the Year Award from the Western Australian Government late last year, is confident of the savings the technology will bring to drill rig operators.

“The pulling, checking, refitting and running-back operation of the coring equipment can typically take 10 to 12 hours, which, at the above rig rates, equates to very substantial cost savings,” he told Australian Mining.

Another key benefit of the technology, says van’t Riet, is that it provides a detailed log to geologists after a core is recovered. This detailed log not only tells geologist exactly where a core was captured in a particular formation, but also where a core was potentially lost or dropped out when the core assembly was brought back to surface.

The man behind the Core Level Indicator System, Bill Connell, developed the tool in response to the frustration, uncertainty and guesswork surrounding the existing conventional coring process. However, development of the system has not been without its share of challenges, according to van’t Riet.

“The main challenges in developing the system has been dealing with the down hole environment,” he said.

“Tools must withstand pressures up to 10,000 psi and temperatures up to 150°C. Then there are the different muds in which to operate. Another challenge has been getting access to test wells. While interest in innovation is strong, it’s a case of ‘not it in my well; find another well to test it in’, and given that these wells are $10 million plus to drill, you can see why there is some reluctance within the industry to make wells available to new products.”

Despite the challenges Coretrack is close to perfecting the system to withstand the heat, pressure and other technical requirements of core sampling. With the continuing help of Halliburton and several oil companies access to wells for testing has been more easily accommodated.

The next step for the company, says van’t Riet, is to refine the tool’s telemetry.

“The recorder unit is 95% finished and ready for market. However, the telemetry requires further development — particularly the telemetry from the core level indicator recorder unit to the top of the core barrel,” van’t Riet said.

“We’re working with Edith Cowan University on a magnetic pulse telemetry system, while working on an acoustic telemetry system with other parties as a fallback position,” he said.

To listen to a podcast of the interview with Nanne van’t Riet visit the Unearthed Report on Australian Mining at

Coretrack Limited

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