Ultra-Deep Copper Drilling Rig High Plateau: CSD3000 in Ali, Tibet, China

Executive Summary

At an elevation of 5,100 m on the Qinghai-Tibet Plateau in Ali (Ngari), Xizang Yanyu Mineral Exploration Co., Ltd. targeted a deep copper horizon that pushed beyond the reach of mid-class exploration rigs. The contractor deployed the CORTECH® CSD3000 — a 3,000 m-class ultra-deep crawler core drilling rig — and completed a 1,688.88 m deep hole at a 75 mm final diameter in 52 days. Where a standard rig struggles to control a 1,600 m steel drill string, the CSD3000's balance-principle weight-on-bit control, 8,170 Nm top drive, telescopic mast and extendable outriggers delivered stable, high-recovery coring on the high plateau — proving the ultra-deep copper drilling rig high plateau capability needed to test deep copper deposits.

Project Background & Challenge

This program shared the thin-air, cold and remote conditions of high-altitude Tibet, but its defining challenge was depth rather than altitude:

• Ultra-deep target horizon: the copper ore body lay at 1,688.88 m. Below about 1,500 m, the cumulative weight of the drill string becomes so large that ordinary pressure-feeding can buckle rods, wreck bits and ruin core recovery.
• Heavy-string management: at this depth, lifting, running and supporting the string requires high pullback and a stable mast base — not a light exploration rig.
• Plateau stability: drilling a 23.5-ton rig and long strings on uneven, soft plateau pads demands a rock-solid base to avoid vibration-induced deviation.
• Schedule pressure: like all plateau work, the campaign had to finish inside the narrow high-altitude working window.

Our Solution

Xizang Yanyu selected the CORTECH® CSD3000, the flagship ultra-deep crawler wireline core drilling rig, specifically for its deep-hole string control. The decisive features:

• Balance-principle WOB control: instead of coarse pressure feeding, the CSD3000 uses a hydraulic balance loop to neutralize the dead weight of the long string and apply micro-precise weight-on-bit (up to 90 kN feed, 250 kN pullback), eliminating rod buckling and protecting diamond bits at extreme depth.
• 3,000 m-class depth rating: reference coring depths of 3,000 m (B size, 55.5 mm), 2,300 m (N size, 71 mm), 1,600 m (H size, 89 mm) and 1,050 m (P size, 114 mm) gave the 1,688.88 m production hole deep margin.
• High-torque power: the 242 kW Cummins L8.9CS4 330C turbocharged engine drives an 8,170 Nm top drive through a 28 MPa hydraulic system, sustaining torque through hard deep-crust formations.
• Telescopic mast and side-shifting head: the 11.2–13.7 m telescopic mast balances low transport clearance with high rod pulls, while the side-shifting top drive clears the borehole for fast wireline tripping.
• Extendable outrigger stabilizers: hydraulic legs widen the footprint and dampen the vibration of the 8,170 Nm head on soft, uneven plateau ground, protecting hole straightness.

Key Results

For the full technical specifications of the CORTECH® CSD3000, see the CSD3000 product page.

Customer Value & ROI

• Reached the deep ore body: the 1,688.88 m hole delivered core from a horizon that mid-class rigs could not economically test, converting a prospective deep target into a drillable resource.
• Protected bit and string investment: balance-principle WOB control avoided rod buckling and bit damage on a 1,600 m string, cutting costly rod loss and redrills.
• Stable on soft plateau ground: outrigger stabilizers and the telescopic mast kept the hole straight, supporting reliable grade and geometry data.
• Delivered in 52 days: the campaign finished inside the plateau working window, keeping the client's resource evaluation on schedule.

FAQ

How deep can an ultra-deep copper drilling rig drill?

The CORTECH CSD3000 is rated for up to 3,000 m of wireline coring on B-size (55.5 mm) rods, 2,300 m on N-size (71 mm), 1,600 m on H-size (89 mm) and 1,050 m on P-size (114 mm). In this Ali, Tibet project it drilled a 1,688.88 m copper exploration hole at 75 mm.

What is balance-principle WOB control?

At 1,500–3,000 m the drill string's own weight is so large that ordinary pressure feeding buckles rods. The CSD3000 uses a hydraulic balance loop to counteract the string's deadweight and apply micro-precise weight-on-bit (up to 90 kN feed, 250 kN pullback), protecting rods and diamond bits.

How does the CSD3000 handle heavy 1,600 m drill strings?

It combines 250 kN pullback and 90 kN feed, an 8,170 Nm top drive, a telescopic 11.2–13.7 m mast and extendable outrigger stabilizers that widen the base and dampen vibration on soft ground to keep the long string stable and the hole straight.

How long did the 1,688.88 m Tibet copper hole take?

The CSD3000 completed the 1,688.88 m hole at 75 mm diameter in 52 days at a 5,100 m elevation site, including tripping, coring and long-string handling on the high plateau.

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