ZJ70/4500 Skid-Mounted Refurbished Drilling Rig
1. Product Overview
This unit is a ZJ70/4500 onshore skid - mounted oil drilling rig, fully refurbished to industry high standards. It is available in two versions: ZJ70J mechanical drive and ZJ70DB AC VFD electric drive. Featuring a modular skid - integrated structure and low-level design for integral hauling, it enables easy installation and fast relocation.
It is mainly used for onshore deep oil & gas wells, geothermal wells, deep water wells, mineral exploration wells, cluster wells, directional wells and horizontal wells. It operates reliably in extreme climates from - 45°C to +55°C, including deserts, Gobi, plateaus and remote alpine mining areas. The rig complies with API and Chinese industry standards, has no structural damage and no major accident history, and its performance after refurbishment is close to new equipment.
2.1 Drilling Capacity
Nominal drilling depth: 4 ½" DP: 4,500-7,000 m; 5" DP: 3,600-5,800 mMaximum hook load: 4,500 kN (450 tons)Drawworks rated power: 1,470 kW / 2,000 HPHoisting system: 12 - line configuration, with φ38 mm drilling line2.2 Mast & Substructure
Mast type: K - type two - section telescopic mastEffective mast height: approx. 53 mDrill floor height: 7.5 m / 9 m / 10.5 m (optional)Substructure clearance: ≥7.2 m, suitable for large BOP installationSite relocation cycle: 5-7 days for full move2.3 Rotary System
Standard ZP495 rotary table, opening diameter 1,257.3 mm (49.5")High torque, smooth operation; supports independent or combined drive for deep-well applications.2.4 Mud & Power System
Standard: 2 × F - 1600 high - pressure mud pumpsComplete 4 - stage solids control system: shale shaker, desander, desilter, centrifuge and mud tanks for efficient mud treatmentMechanical (ZJ70J): High-power diesel engine combination driveElectric (ZJ70DB): Multiple high-power diesel generator sets + full VFD system for stable and energy-saving power output3.1 Borehole Diameter
1st spud: 26" / 24"2nd spud: 17.5" / 12.25"3rd / 4th spud: 8.5" / 6"Max. borehole diameter: 26", covering all section requirements.3.2 Applicable Bit Types
PDC bits, tricone roller bits, diamond core bits, directional bits, reaming bits - suitable for soft, medium-hard, hard and gravel formations.
3.3 Drilling Methods
Conventional rotary drilling, top drive drilling (optional), mud positive circulation, air/foam drilling, directional & horizontal drilling - flexible for various formations and trajectories.
4.1 Steel Structure
Mast, substructure and drawworks base: full NDT inspection, straightening, weld repair, sandblasting and heavy anti-corrosion coating (≥200 μm).
4.2 Hoisting Components
Crown block, traveling block, hook: all bearings replaced, load tested (1.25× rated load). Drawworks: fully disassembled & overhauled, worn gears/brakes replaced, no-load & full-load run-in passed.
4.3 Hydraulic & Pneumatic Systems
All valves, cylinders and high-pressure lines: disassembled, cleaned, seals 100% replaced. 24 - hour zero - leak pressure test. Pneumatic system: aging components renewed.
4.4 Electrical & Control System
Motors, transformers, VFDs: insulation tested; aging cables & faulty components replaced. PLC console & driller cabin fully calibrated. All pressure, torque and depth gauges recalibrated or replaced.
4.5 Main Assemblies
Rotary table & mud pumps: complete strip - down, bearings, liners, pistons and valves replaced; clearances adjusted for long-term stability.
4.6 Safety System
Anti-collision limit, emergency stop, anti-jam protection: full functional test. Fire protection, lightning protection, handrails and walkways: repaired or replaced to meet site safety requirements.
5.1 Standard Package
K-type mast + skid-integrated substructure2,000 HP main drawworksComplete 12-line hoisting systemZP495 rotary table + bushingsFull power unit2 × F1600 mud pumps4-stage solids control systemVFD / mechanical control systemDriller consoleComplete wellhead toolsLighting & safety facilities5.2 Optional Upgrades
DQ700 top driveHigh-pressure BOP stackAuto-drilling systemAutomated pipe handlingLow-temperature anti-freeze packageDesert dust-proof packagePlateau power boost package6. Key Advantages
Cost - effective: 50-65% of new rig price with near-new performance.High reliability: Critical wearing parts renewed, structures NDT-approved, low failure rate, easy maintenance.Fast mobilization: Skid-modular design for quick rig - up and relocation, saving time and transport costs; ideal for cluster wells.High capacity: 450 - ton hook load for deep & ultra-deep wells; wide application range.Short delivery: In stock, 30-45 days delivery (new rigs: 6-12 months).Good parts availability: Standard components, easy after - sales support, long service life under normal conditions.7. Price
Price depends on manufacture year, refurbishment grade, brand, overall condition, optional equipment and delivery terms.
8. Warranty & Documentation
Warranty: 6 - month coverage for core components.Delivered documents: Refurbishment report, NDT report, load test report, electrical test report, factory acceptance certificate.Services: Full containerized export, customs clearance, overseas logistics, remote technical support.
