
Crawler-Mounted Water Well Drilling Rig

The WR400S is a telescopic mast crawler water well drilling rig that combines 400 m drilling depth, 6 m drill pipe operation capability, and transport convenience. The S in the model represents the telescopic mast. Compared with a conventional straight mast structure, it can shorten the overall transport profile while continuing to support direct construction with 6 m drill pipes or 6 m casing in working condition. This makes it more suitable for water well drilling teams that need frequent loading and relocation while hoping to reduce the number of pipe connections.
The value of the telescopic mast is mainly reflected in the balance between transport and operation. During relocation, the mast can shorten the transport profile, reducing the difficulty of loading, road passage, and site turning. After reaching the hole position, it can be extended into working condition and continue to maintain 6 m drill pipe construction capability. For cross-regional drilling, village and township projects, and continuous construction across multiple sites, this structure makes transport arrangements more convenient.
The WR400S supports direct operation with 6 m drill pipes and 6 m casing, with recommended drill pipe diameters of 89 / 102 mm. Long drill pipes can significantly reduce the number of pipe connections in 300–400 m class water wells, lowering auxiliary time and manual handling frequency. For projects requiring continuous footage, reducing drill pipe connection and disconnection often improves the actual construction rhythm more than simply increasing fast-action speed.
The maximum drilling depth is 400 m, and the drilling diameter is 105–325 mm, covering a large number of rural, agricultural, industrial, and general engineering water well needs. For areas where shallow groundwater is unstable, the water table is relatively deep, or greater water-finding margin is needed, a 400 m class rig has a wider construction range than small shallow well rigs. The actual completed well depth should still be determined according to hydrogeological conditions.
The WR400S is suitable for irrigation well construction in farmland, orchards, greenhouses, and nurseries. Large-scale agricultural projects often require continuous construction of multiple water wells. The 6 m drill pipe can reduce pipe connection frequency, while the crawler chassis facilitates movement on field roads and general unpaved sites. Well diameter and pump type should be designed according to planned water output and irrigation area.
In villages where centralized water supply coverage is insufficient or groundwater depth is relatively large, the WR400S can be used for household water wells, village-level water supply wells, and small public water source wells for schools, clinics, and similar facilities. The 400 m class drilling depth provides greater space for finding aquifers, but the target well depth should still be reasonably determined based on local hydrogeological data before formal construction.
Livestock farms and ranches require long-term stable water sources for drinking, cleaning, and production. The WR400S can be used for livestock water wells and remote agricultural projects. Diesel power does not depend on a fixed power grid, making it suitable for construction sites far from towns. For long-term pumping wells, well casing, screen pipes, and pump configuration should be designed according to the water-bearing layer.
Factories, workshops, construction camps, and infrastructure projects may also require independent groundwater sources. The WR400S can be used for general production auxiliary water, construction water supply, and site service water wells. In environments with limited space in plant areas, enclosures, and roads, the telescopic mast offers advantages for transport and site entry.
The equipment has a lifting force of 22 T and an axial pressure of 4 T. In 400 m class boreholes, drill pipe weight, borehole wall friction, and casing weight gradually increase, so greater lifting capacity is beneficial for normal tripping and tool recovery. If abnormal pulling resistance occurs, the hole should first be cleaned and the presence of diameter reduction, falling blocks, or sticking should be determined. The maximum lifting force should not be used directly for forced handling.
The rotary system has a maximum torque of 8000 / 4000 N·m, corresponding to maximum speeds of 75 / 150 r/min. The low-speed high-torque mode is more suitable for larger diameters and higher resistance conditions, while the higher-speed mode is suitable for drilling stages with lower resistance. During construction, switching should be based on drilling tools, rock formations, and cuttings return conditions rather than maintaining a single mode for a long time.
Fast lifting and feed are mainly used for power head return, drill pipe handling, and non-drilling actions, which can reduce auxiliary time. Actual formation footage efficiency still depends on rock hardness, hole diameter, bit, DTH hammer, and air compressor capacity. Long drill pipes combined with fast hydraulic actions can further reduce ineffective working time.

When using a DTH hammer, the recommended working air pressure is 1.2–3.5 MPa, and the air consumption is 16–55 m³/min, compatible with medium and high-pressure series DTH hammers. Air compressor selection needs to consider both pressure and displacement. Especially in large-diameter, hard rock, and high-altitude environments, insufficient displacement will directly affect impact and cuttings removal.
After entering relatively complete rock formations such as limestone, sandstone, and granite, DTH hammer pneumatic drilling can be used. Hard rock construction should ensure DTH hammer lubrication and sufficient air volume, and regularly check bit wear. If cuttings return suddenly decreases or air pressure is abnormal, the hole should be cleaned in time to prevent cuttings accumulation at the bottom and drilling tool sticking.
Data shows that the WR400S also supports mud drilling. For soil, clay, sand, and other loose overburden layers, mud circulation can help with wall protection and cuttings carrying. After the upper loose layer is stabilized, DTH hammer can then be used in rock formations, better balancing hole stability and hard rock drilling efficiency.
Weathered rock often has faster footage, but the borehole wall is prone to falling blocks and diameter reduction. When soft and hard layers alternate, rotary torque and footage speed change frequently, so feed and rotation speed should be adjusted according to drilling tool load. When the upper unstable hole section is thick, follow-up casing can be considered to reduce borehole wall problems in the deep hole stage.
Fractured and broken formations may cause air leakage, sticking, and falling blocks. During construction, excessively fast feed should be reduced, continuous hole cleaning should be maintained, and foam or casing should be selected according to actual conditions. If air leakage is severe, simply increasing air compressor pressure is not enough; it is also necessary to determine whether large fissures or cavities exist.
After entering the main aquifer, groundwater will change DTH hammer cuttings removal and working conditions. The aquifer depth should be recorded in time, and air supply and hole cleaning methods should be adjusted according to water inflow. During well completion, well casing, screen pipes, and sealing sections should be reasonably arranged to ensure long-term pumping performance.
The equipment walking speed is about 2.5 km/h, and the maximum climbing angle is referenced at 21°. The crawler structure is suitable for rural roads, gravel ground, and general uneven sites. Before relocation, the mast should be in a safe transport state, and ground bearing capacity, slope, and wet slippery conditions should be evaluated to avoid heavy equipment sinking on soft ground.
The hydraulic outrigger stroke is 1.6 m, which can be used for equipment leveling and stable support. 400 m class water well construction has a relatively long cycle, and the level state of the equipment affects hole deviation and mast stress. On soft ground, pads should be used to ensure uniform outrigger stress and avoid settlement during construction.

The WR400S uses a 92 kW Yuchai engine to provide power for rotation, feed, crawler walking, and auxiliary hydraulic systems. During long-term hard rock construction, focus should be placed on checking engine cooling, air filters, and hydraulic oil temperature. Dusty construction sites require more frequent cleaning of radiators and filter elements.
The auxiliary winch has a lifting force of 1.5 T and can be used to handle DTH hammers, drill pipes, casing tools, and other site accessories. When using long drill pipes and long casing, reasonable lifting points and manual guidance should be used to avoid lateral swinging of drill pipes or collision with the mast.
The overall weight is about 9.8 T, and the dimensions are about 6.26 × 1.85 × 2.43 m. Compared with a fixed long mast, the telescopic structure can improve the transport profile and is more suitable for construction teams that need frequent loading. During transport, still check mast locking, equipment fixing points, and separate bundling of drill pipes.
Mud pumps, centrifugal pumps, generators, and foam pumps can be selected according to the project. Loose layer projects need mud systems more, hard rock projects focus on air compressors and DTH hammers, and formations with severe air leakage may use foam assistance. Configuring accessories according to actual working conditions is more conducive to controlling equipment investment.
In addition to routine inspection of the engine, hydraulic system, crawler, outriggers, and drilling tools, the WR400S should also focus on checking the telescopic mast guide rails, hydraulic cylinders, pins, and locking structures. When using 6 m drill pipes or casing, ensure the mast is fully extended and reliably fixed, avoiding drilling and drill pipe handling in an unlocked state.
Due to differences in actual geological conditions, downhole tools, drilling angle, and operating methods, the final drilling efficiency, drilling depth, and well completion effect should be based on on-site working conditions.
| Parameter Item | Parameter Value |
|---|---|
| Basic Parameters | |
| Product Model | WR400S |
| Equipment Type | Telescopic mast crawler fully hydraulic water well drilling rig |
| Maximum Drilling Depth | 400 m |
| Drilling Diameter | 105–325 mm |
| Applicable Formations | Loose formations and rock formations |
| Telescopic Mast and Drill Pipe Configuration | |
| Mast Structure | Telescopic mast |
| Drill Pipe Length | 6 m |
| Casing Length | Supports direct operation with 6 m casing |
| Recommended Drill Pipe Diameter | 89 / 102 mm |
| Rotary and Feed System | |
| Axial Pressure | 4 T |
| Lifting Force | 22 T |
| Fast Lifting Speed | 29 m/min |
| Fast Feed Speed | 56 m/min |
| Maximum Rotary Torque | 8000 / 4000 N·m |
| Maximum Rotary Speed | 75 / 150 r/min |
| Auxiliary Winch Lifting Force | 1.5 T |
| Hydraulic Outrigger Stroke | 1.6 m |
| Pneumatic System Matching | |
| Recommended Working Air Pressure | 1.2–3.5 MPa |
| Recommended Air Consumption | 16–55 m³/min |
| Compatible DTH Hammer | Medium and high-pressure series |
| Power System | |
| Engine Brand | Yuchai |
| Engine Power | 92 kW |
| Walking and Overall Parameters | |
| Walking Speed | 2.5 km/h |
| Maximum Climbing Angle | 21° |
| Overall Weight | 9.8 T |
| Dimensions | 6.26 × 1.85 × 2.43 m |
| Drilling Methods | |
| Top drive hydraulic rotary drilling | Suitable for conventional water wells and construction with different diameters |
| DTH hammer drilling | Suitable for weathered rock, fractured rock, and relatively complete rock formations |
| Mud drilling | Suitable for soil, clay, sand, and other loose formations |
| Optional Accessories | |
| Mud pump | Optional |
| Centrifugal pump | Optional |
| Generator | Optional |
| Foam pump | Optional |
| Typical Applications | |
| Agricultural irrigation | Water wells in farmland, orchards, greenhouses, and large-scale planting areas |
| Rural water supply | Groundwater development for households, villages, and small communities |
| Livestock water | Water supply for livestock farms, ranches, and remote agricultural projects |
| Industrial water | Factories, workshops, and general production auxiliary water wells |
| Construction projects | Construction site water supply and general groundwater drilling |

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