SJ Self-Propelled Workover Rig Specifications (235HP to 1300HP)

1

SXJ150 (XJ150)

300 (67440) / 585 (131508)

175 (235)

1. Hook wear from repeated light-load cycles; 2. Hydraulic system leakage due to seal aging; 3. Engine overheating from prolonged low-speed operation.

1. Inspect hook latch and wear liner weekly; 2. Replace hydraulic seals every 12 months or if leakage is detected; 3. Avoid idling for over 30 minutes to prevent engine overheating.

Hook: Alloy steel (40Cr) with quenching treatment (HRC 45-50); Frame: Q355B low-alloy steel for corrosion resistance; Hydraulic seals: Nitrile rubber (NBR) compatible with oilfield fluids.

2

SXJ250 (XJ250)

400 (89920) / 675 (151740)

242 (325)

1. Wire rope abrasion from contact with wellhead equipment; 2. Gear wear in the transmission system from load fluctuations; 3. Tire damage from uneven oilfield terrain.

1. Lubricate wire rope every 5 working days; 2. Adjust transmission gear backlash quarterly; 3. Inspect tire pressure and tread depth before each operation.

Wire rope: Galvanized steel (6×19S+FC) with tensile strength ≥1570MPa; Transmission gears: 20CrMnTi alloy steel; Tires: Off-road radial tires (14.00-24) for rough terrain.

3

SXJ350 (XJ350)

600 (134880) / 900 (202320)

287 (385)

1. Hook bearing wear from increased load cycles; 2. Hydraulic cylinder corrosion from outdoor exposure; 3. Engine air filter clogging from oilfield dust.

1. Replace hook bearings every 200 working hours; 2. Apply anti-corrosion coating to hydraulic cylinders semi-annually; 3. Clean or replace air filters every 30 working days.

Hydraulic cylinders: 27SiMn alloy steel with chrome plating; Hook bearings: High-carbon chromium bearing steel (GCr15); Air filter: High-efficiency paper filter with dustproof cover.

1

SXJ400 (XJ400)

980 (220304) / 1020 (229296)

335 (450)

1. Transmission gear fatigue from frequent high-load starts; 2. Hydraulic valve wear from pressure fluctuations; 3. Frame deformation from uneven ground loading.

1. Avoid sudden high-load starts; 2. Calibrate hydraulic valves every 6 months; 3. Level the rig before operation to distribute load evenly.

Transmission gears: 40CrNiMoA alloy steel with carburizing treatment; Hydraulic valves: Cast steel (WCB) with precision machining; Frame: Welded Q355B steel with reinforced beams.

2

SXJ450 (XJ450)

980 (220304) / 1125 (252900)

354 (475)

1. Wire rope fatigue from heavy load hoisting; 2. Brake pad wear from frequent emergency braking; 3. Engine oil degradation from high-temperature operation.

1. Inspect wire rope for broken strands monthly; 2. Replace brake pads when thickness is less than 5mm; 3. Change engine oil every 500 working hours.

Wire rope: Improved galvanized steel (6×37S+FC) with tensile strength ≥1770MPa; Brake pads: Ceramic-based composite material; Engine oil: Heavy-duty diesel oil (API CJ-4).

3

SXJ550 (XJ550)

1176 (264365) / 1350 (303480)

403 (540)

1. Hydraulic pump wear from prolonged high-pressure operation; 2. Hook nut loosening from vibration; 3. Electrical system damage from oilfield moisture.

1. Monitor hydraulic pump pressure and noise; 2. Retighten hook nuts weekly and use thread lockant; 3. Keep electrical control cabinet dry and clean.

Hydraulic pump: Cast iron (HT250) with hardened rotor; Hook nut: 40Cr alloy steel with lock washer; Electrical components: IP65 waterproof rating for moisture resistance.

1

SXJ650 (XJ650)

1350 (303480) / 1470 (330456)

403×2 (540×2)

1. Dual-engine synchronization failure from uneven load distribution; 2. Hydraulic hose wear from high pressure; 3. Frame weld fatigue from extreme loads.

1. Calibrate dual-engine synchronization monthly; 2. Inspect hydraulic hoses for bulges or cracks weekly; 3. Check frame welds for cracks semi-annually.

Dual engines: Heavy-duty diesel engines (API CJ-4); Hydraulic hoses: High-pressure steel wire braided hoses (GB/T 3683); Frame: Q460 steel with reinforced welds.

2

SXJ1000 (XJ1000)

1500 (337200) / 1700 (382160)

470×2 (630×2)

1. Hook and block wear from ultra-heavy load hoisting; 2. Transmission system overheating from long working hours; 3. Hydraulic oil contamination from debris.

1. Replace hook and block every 800 working hours; 2. Monitor transmission oil temperature (keep below 90°C); 3. Filter hydraulic oil every 300 working hours.

Hook and block: Alloy steel (35CrMoA) with heat treatment; Transmission oil: Synthetic gear oil (ISO VG 220); Hydraulic oil filter: High-precision (10μm) filter element.

3

SXJ1200 (XJ1200)

1800 (404640) / 2250 (505800)

522×2 (700×2)

1. Structural deformation from extreme hook loads; 2. Brake system failure from heavy load braking; 3. Electrical system short circuits from high-power operation.

1. Never exceed maximum hook load; 2. Inspect brake system daily before operation; 3. Check electrical wiring for insulation damage monthly.

Structure: Q690 high-strength alloy steel; Brake system: Disc brakes with hydraulic power assist; Electrical system: High-voltage (24V) waterproof wiring harness.

How to select the right SJ self-propelled workover rig model for my well workover needs?

Choose based on well depth and required hook load: Low-power (235-385HP) for shallow wells (≤1500m); Medium-power (450-540HP) for mid-depth wells (1500-3000m); High-power (1080-1300HP) for deep wells (>3000m). Match nominal hook load to routine task requirements, with max load reserved for emergency scenarios.

What are the key maintenance intervals for high-power dual-engine rigs (e.g., SXJ1000)?

Dual-engine oil change: 500 working hours; Hydraulic oil filtration: 300 working hours; Wire rope inspection: Monthly; Hook and block replacement: 800 working hours; Synchronization calibration: Monthly. Follow API Spec 8C and manufacturer guidelines for harsh environment adjustments.

How to prevent hydraulic system failure in SJ workover rigs?

Keep hydraulic oil clean (filter regularly), inspect hoses for damage weekly, replace seals every 12 months, and calibrate pressure valves quarterly. Use compatible hydraulic oil (ISO VG 46) and avoid sudden pressure spikes. Store rigs in covered areas to protect hydraulic components from outdoor exposure.