What To Look For When Choose A Drilling Rig?

Underground diamond drilling is similar to surface drilling, yet several key differences must be taken into account when selecting drilling equipment.

Different objectives

Underground drilling prioritizes production efficiency and penetration speed to avoid slowing down ore‑extraction workflows. Optimized penetration rates are critical. High‑performance coring bits with good rotational speed help achieve faster drilling progress.

Unknown versus known ground

Most mines have multi‑year operating history, so rock formation characteristics are well‑understood. Numerous boreholes have been drilled beforehand, and geological surprises are rare. Instead of using general‑purpose coring bits for varied ground conditions, drill crews can select bits tailored for specific rock types. With known formation properties, operators can choose bits with higher crown profiles to reduce bit‑replacement frequency.

Drilling depth

Underground boreholes are usually relatively shallow, for example around 200 meters instead of 1000 meters. This allows drillers to adopt conventional drilling techniques rather than cable‑tool drilling. Coring bits for conventional drilling produce fine cuttings and deliver improved penetration rates.

Drill hole orientation

Underground boreholes can point downward, upward, or at inclined angles. Different hole orientations may require coring bits with different matrix formulas. In upward‑drilling scenarios, you may need to switch away from the matrix used for downward holes. When drilling downwards, drill‑pipe weight applies extra loading on the bit. For upward drilling, this rod‑derived weight disappears; you must compensate by selecting higher‑series bits with softer matrices. Softer matrices expose diamond grains easily and keep the coring bit sharp even without sufficient bit‑weight pressure.

Low Power Drilling Rigs

Underground working space is limited, therefore drilling rigs deployed underground tend to be compact and low‑power. When drilling upward with low‑power rigs, coring bits equipped with softer matrices are preferred. As noted above, softer matrices readily expose diamond crystals, maintaining sharp cutting performance and acceptable penetration even under insufficient feed‑pressure output.

Proper drilling‑equipment selection heavily influences overall drilling performance. Formation type is important, yet underground diamond drilling involves additional critical considerations. Our engineering team shares practical underground‑drilling guidance: start underground boreholes with pre‑worn coring bits. Pilot‑hole drilling may damage bit surfaces, so reserve brand‑new bits for formal drilling sections.