How to Choose a Workover Rig: Match Capacity to Your Well Program

Start with the well, not the brochure

A workover rig is chosen against a specific well program: pulling and running tubing, fishing stuck pipe, paraffin removal, scale cleaning, plugging removal, or heavy installation of completion tools. The mistake buyers make is specifying by horsepower alone. The correct sequence is to establish the maximum planned intervention depth, calculate the heaviest string you may ever have to pull, then select the chassis configuration that can move that capacity between your well sites. Every well intervention in the workover rig line is engineered around those three numbers, and this guide walks through how they interact.

If your portfolio spans shallow production wells and deep rehabilitation holes, do not buy a unit for the average well. Size to the heaviest and deepest intervention in your contract, because over-pulling a marginally rated rig is where rod failures and downtime start.

Three core parameters that decide the class

• Nominal working depth — the maximum intervention depth with the work string diameter you actually run. Compare the 7000 m class of a heavy unit against the 2000 m class of a compact platform unit before judging the number believable.
• Maximum static hook load — the weight the mast and hoist can hold dead, not the average pulling load. Add safety margin for stuck-string emergencies; hook load, not horsepower, sets the failure boundary.
• Rated lifting power — the hoist engine output, which governs how fast you pull long strings and how comfortably the unit handles repeated heavy lifts in a day.

On the SJ product range, the truck mounted workover rig XJ1000 is rated for 7000 m nominal working depth with 73 mm drill pipe, a 3150 kN maximum static hook load, and 1000 HP rated lifting power. The heavier XJ1350 class holds the same 7000 m depth envelope but steps hook load up to 4000 kN and lifting power to 1350 HP, which is the correct escalation path when your program includes ultra-deep well repair and high-pressure fracturing support.

Compare real SJ workover specifications

The jump from 3150 kN to 4000 kN is not cosmetic: it changes which stuck-pipe scenarios the rig can cover without backup units, and it is the first parameter buyers recheck when deepening the intervention plan.

Truck-mounted mobility versus offshore compactness

For onshore fields, a truck mounted workover rig pays back its chassis cost through rig-up time. The XJ1000 and XJ1350 use a vertical folding hydraulic lifting derrick and travel at up to 75 km/h and 70 km/h respectively, meaning one unit can rotate through multiple well locations per week instead of waiting for a crane-assisted skid move. Operating temperature range of -40 C to +55 C also matters for seasonal field planning, and the executive standard of API 4F, API 7K and ISO 9001 applies to both truck units.

Offshore and platform environments demand the opposite trade-off: footprint, wind resistance and marine certification. The offshore platform workover rig HXJ225 uses a marine wind-resistant compact vertical derrick rated for 20 m/s working wind speed, a ZP205 rotary table, 25 MPa standpipe working pressure, and mechanical drive with optional explosion-proof VFD drive. Its 1580 kN hook load and 2000 m depth rating are deliberately matched to platform well counts, not to onshore deep-hole capability.

Cost and logistics decision points

• If wells are scattered over a road network, truck-mounted units win on mobilization cost per intervention.
• If rig moves require over-width permits or local road limits, discuss chassis load, braking and lighting customization during technical clarification; SJ adapts chassis parameters to different highway certification regimes.
• If the unit must survive desert heat, coastal salt spray or arctic cold, specify the climate package at order stage rather than retrofitting in the field.
• For platform work, compactness and wind rating override raw power; do not compare offshore hook load directly against onshore units.

HuBei SJ Petroleum Machinery Co.Ltd manufactures these units with structural components built to API 4F and API 7K referenced design and testing practice, and the company profile references ISO 9001, HSE, and API Q1 quality management. Design drawings, referenced certificates, operation manuals and export documentation are prepared for buyer review during technical clarification.

A short checklist before you request a quotation

Lock these answers first: maximum intervention depth with your real work string diameter; heaviest anticipated pulled string plus stuck-pipe margin; number of rig moves per month and the road conditions between locations; ambient temperature extremes; and whether the site is onshore, desert, or offshore platform. With those five answers, the correct workover rig class narrows to one or two models, and the specification comparison becomes a documentation review rather than a guessing game.