RC400

⛏️ RC400 400 m Crawler Reverse Circulation Drill Rig

The RC400 is a crawler reverse circulation drill rig designed for mineral exploration, geological sampling and medium-to-deep water well construction. Compared with ordinary water well drill rigs, it places greater emphasis on reverse circulation cuttings return and sampling capability; compared with core drill rigs, it mainly obtains cuttings samples returned by depth rather than continuous intact cores. With a maximum drilling depth of 400 m and a drilling diameter of 105–305 mm, it is suitable for mine exploration teams, geological service companies and drilling contractors that need to undertake both exploration holes and water well projects.

🔄 The core of reverse circulation drilling is to return cuttings through the inside of the drill pipe

Reverse circulation drilling usually establishes an independent return channel through dual-wall drill pipes. After compressed air drives the downhole drilling tool, cuttings quickly return to the surface through the inner tube. Compared with ordinary outer annulus discharge, this method helps shorten the mixing path of cuttings in the hole, facilitates collecting samples by depth intervals, and provides a basis for on-site geological judgment and subsequent laboratory analysis.

🧪 High cuttings sampling efficiency, suitable for early-stage mineral exploration and infill verification

The advantage of RC drilling is not obtaining complete cores, but quickly obtaining continuous cuttings samples. For gold, copper, iron, lithium and other mineral exploration, samples can be collected at fixed footage intervals, recording changes in color, lithology, alteration and mineralization, and sent to the laboratory for grade analysis. For projects that require a large number of boreholes to quickly verify anomalous zones, the reverse circulation method offers high on-site efficiency.

🥇 Gold exploration: quickly verifying mineralization anomalies and orebody boundaries

In gold projects, the RC400 can be used for surface anomaly verification, mineralization investigation below overburden, orebody boundary control and peripheral extension drilling. Compared with continuous coring, RC sampling emphasizes efficiency and sample quantity, making it suitable for quickly establishing more borehole control points in large exploration areas, and then deciding which key areas require further core drilling based on the results.

🟠 Copper, iron and lithium investigation

Copper, iron and lithium projects can also use reverse circulation samples to identify lithology, alteration and mineralization trends. For areas with thick overburden or inconspicuous surface outcrops, obtaining cuttings at different depths through 400 m-class boreholes can help exploration personnel understand stratigraphic changes and potential mineralization locations, and provide a basis for the next stage of borehole layout.

📐 45° / 90° working angles facilitate hole layout for different targets

The working angles given are 45° and 90°, allowing inclined holes or near-vertical holes according to project needs. Vertical holes are suitable for groundwater, overburden investigation and some mineral exploration, while 45° inclined holes can be used for inclined orebodies, structural zones or specific target verification. Before formal construction, the hole direction and hole angle should be confirmed according to the geological design.

📏 400 m drilling depth covers medium-depth exploration and water well projects

The maximum drilling depth of 400 m and drilling diameter of 105–305 mm enable the RC400 to undertake both mineral exploration holes and medium-to-deep water well construction. Actual drilling depth will be affected by hole diameter, drill pipe, air compressor capacity, formation conditions, hole deviation and drilling tool wear, so 400 m should be understood as a reference capability under typical configuration.

🔩 89 / 102 mm RC drill pipes are suitable for conventional reverse circulation systems

Recommended RC drill pipe diameters are 89 / 102 mm, with a drill pipe length of 3 m. RC drill pipes differ in structure from ordinary single-wall drill pipes and require reliable sealing and connection of the inner and outer channels. During construction, the dual-wall drill pipe joints, seals and inner tube wear should be checked regularly to avoid air leakage and sample contamination affecting sampling quality.

💪 22 T lifting force provides margin for handling 400 m-class drill strings

The RC400 has a lifting force of 22 T and an axial pressure of 6 T. The strong lifting capacity can be used for tripping drill pipes, recovering drilling tools and some casing operations. If pulling resistance suddenly increases during reverse circulation drilling, first determine whether there are falling blocks, hole shrinkage, sticking or poor cuttings discharge, then take hole cleaning and slow pulling measures.

🔄 8000 / 4000 N·m dual-condition rotary torque

The rotary system has a maximum torque of 8000 / 4000 N·m, corresponding to maximum speeds of 75 / 150 r/min. The higher torque condition is suitable for large-diameter and high-load drilling, while the higher speed is suitable for hole sections with less resistance. Reverse circulation construction should simultaneously consider bit cutting, downhole impact and cuttings return status, and should not pursue speed or torque alone.

💨 1.2–3.5 MPa working air pressure determines RC cuttings discharge capacity

Recommended working air pressure is 1.2–3.5 MPa, with air consumption of 16–55 m³/min. RC drilling has relatively high requirements for both air compressor pressure and displacement. Especially when hole depth increases, hole diameter increases or rock formations are hard, if air volume is insufficient, cuttings return speed will decrease, possibly affecting sampling continuity and hole bottom cleanliness.

🧹 Sample return status directly affects the quality of exploration data

Reverse circulation sampling requires not only "drilling fast" but also ensuring continuous sample return by depth. During construction, observe the returned sample volume, particle size, dust changes and whether there is obvious sample cross-contamination. Each time after adding a rod, cleaning the hole or restarting sampling after stopping drilling, the transition section should be handled according to on-site sampling procedures to avoid mixing samples from different depths.

🏷️ RC sample management is stricter than ordinary water well cuttings discharge

When used for mineral exploration, samples should be numbered, weighed and sealed according to fixed hole depth intervals, and the borehole number, depth, time and abnormal conditions should be recorded. The sampling system, cyclone or sample splitter also need regular cleaning. The RC400 provides a drilling platform; the final sample quality also depends on on-site sampling procedures and personnel operation.

💧 Can also be used for deep water well construction in rural, agricultural and mining areas

Although the RC400 has obvious mineral exploration attributes, the data also lists deep water wells as one of its main applications. For rural water supply, farmland irrigation, industrial water and mining area groundwater development, DTH hammer, mud drilling or other suitable methods can be selected according to formation and well completion requirements. Water well construction does not necessarily require the RC sampling system throughout the entire process.

⛏️ Mining area water supply and mine investigation can share the same platform

Mining projects may require both exploration holes and water wells for domestic use, dust suppression and auxiliary production. The RC400 supports multiple drilling methods and can adjust configuration according to the target of different holes within one project, improving equipment utilization. Exploration holes focus more on sample quality, while water wells focus more on hole stability, well diameter and aquifer.

🌧️ Mud drilling can be used in loose overburden

Soil, clay, sand and gravel layers are prone to collapse and may not be suitable for direct pneumatic RC drilling. The data indicates that this model supports mud drilling, so in the upper loose formations, mud circulation and casing can be selected according to hole wall conditions, and after entering stable rock formations, the process can be switched to pneumatic or reverse circulation.

💎 Weathered rock and intact hard rock can be matched with medium and high air pressure DTH hammers

The equipment can be equipped with medium and high air pressure DTH hammers for weathered rock, fractured rock and relatively intact hard rock. For hard rock conditions, attention should be paid to air compressor displacement, DTH hammer lubrication, bit wear and cuttings return status. If sample return volume decreases, check for air leakage, drill pipe sealing and whether there is accumulated cuttings at the hole bottom.

🧱 Pay attention to sample contamination in fractured zones and fissure-developed formations

Fault fracture zones are prone to falling blocks and local hole enlargement. Cuttings may remain in the hole and then return in concentrated amounts, causing poor correspondence between samples and depth. During construction, control the penetration rate, maintain stable air supply, and keep records in abnormal hole sections. If sampling accuracy requirements are high, on-site geologists should be added to monitor changes in returned samples.

🚜 Crawler chassis is suitable for mining areas and field transfers

The RC400 has a walking speed of about 2.5 km/h, a maximum climbing angle of reference 21°, and an overall weight of about 11 T. The crawler chassis is suitable for gravel roads in mining areas, field construction platforms and generally uneven ground. Due to the relatively large overall weight, ground bearing capacity, slope and transportation route should be confirmed before transfer.

⚡ 92 kW Yuchai engine meets the hydraulic needs of multiple systems

The equipment uses a 92 kW Yuchai engine to provide power for rotation, feed, crawler walking and auxiliary hydraulic systems. Reverse circulation projects are usually also equipped with air compressors, sampling and sample splitting equipment, so fuel, equipment layout and construction access should be planned in advance on site to avoid interference between systems.

🦵 1.6 m hydraulic outriggers ensure stability for inclined hole and high-torque operations

The hydraulic outrigger stroke is 1.6 m, which can be used for equipment leveling and drilling support. Especially in 45° inclined hole construction, equipment stability directly affects hole direction control and operation safety. On soft ground, pads should be added to avoid outrigger sinking during long-term high-load drilling.

🧵 1.5 T auxiliary winch facilitates handling of drilling tools and accessories

The small auxiliary winch has a lifting force of 1.5 T and can be used to handle RC drill pipes, DTH hammers, sampling accessories and other on-site tools. When using the winch, follow rated load requirements and prevent personnel from entering below suspended objects and in the direction of wire rope force.

📦 11 T overall machine and site layout

The overall weight is about 11 T, and the overall dimensions are about 7 × 1.85 × 2.86 m. At a mineral exploration site, in addition to the drill rig itself, air compressors, cyclones, sample splitters, sample bags and vehicles may also be placed at the same time, so the hole platform area should be planned in advance to ensure personnel access and safe distances for equipment.

🧰 Mud pump, centrifugal pump, generator and foam pump are optional

The equipment can be configured with a mud pump, centrifugal pump, generator and foam pump according to the project. Projects with many loose layers rely more on the mud system; formations with severe air leakage may consider foam assistance; remote mining areas may require independent power generation equipment. The specific configuration should be determined around the main drilling method and on-site basic conditions.

⚠️ Construction and sampling precautions

During mineral exploration, focus on checking RC drill pipe sealing, sample return pipelines and sampling equipment to ensure continuous samples and accurate numbering; during water well construction, focus on the hole wall, casing and aquifer. Regardless of the application, the engine, hydraulic system, high-pressure air pipe, rotary head, outriggers and drill pipe connection status should be checked daily.

Due to differences in actual geological conditions, downhole tools, drilling angles and operating methods, the final drilling efficiency, drilling depth, sample recovery and well completion effect should be based on on-site working conditions.

📊 Main technical parameters