The profit margins of opencast mining have decreased, necessitating cost reductions while effcient production is maintained, says wireline-logging company Geoline Logging Services.

Geoline manager Charles Gould states that most opencast mines tend to operate on a “best guess” basis in terms of blasting, which could result in costly mistakes.

He notes that variable seam depths and thicknesses are not always accurately reported by drilling apparatus, and that minimal exploration information often results in poor data input for blasting programmes.

Gould says these challenges can be mitigated through downhole geophysics using methods such as wireline logging.

He states that Geoline uses the latest technology to inexpensively measure aspects, such as coal-seam depth and thickness, in-seam partings and rock strength analysis information, in already drilled blasting boreholes.

“All this information can be conveyed in digital format to the responsible person for input into blasting plan systems.”

Gould further notes that, in terms of wireline logging, precision is important. “Mines often make decisions that are worth millions of rands, based on data from geophysics. The more accurate the information, the easier it is for a mine to make a decision.”

He notes that achieving the necessary level of accuracy is possible only through consistent, careful and precise measurements, adding that borehole conditions can be so varied that results from two similar probes can differ significantly if they are not controlled by accurate calibrations.

Gould says Geoline’s equipment is serviced and calibrated monthly, with a full range of spares in stock to reduce downtime. Records are also kept systematically, which makes it easy to see if a probe has a fault.

Meanwhile, Geoline Logging Services is implementing an ISO 9001 quality management system, he says, adding that the system should be operational by midyear.

“This provides complete transparency in terms of our operating systems. Every task and job has a procedure that has to be followed accurately. Should there be any nonconformance, the reason for it will be easily traceable using this system.”

He says the ISO 9001 quality management system will enable the company to have more control over the way it operates, which, in turn, will enable it to continue providing a service that meets the industry expectations for safety, efficiency and effectiveness.

“It will help us to improve the way we carry out our tasks and, therefore, reduce costs and provide us with a system of continuous improvement.”