Offset drilling equipment
Technical Specifications – Offset Drilling Equipment
The table below shows typical specifications for skidding and walking systems. Custom configurations available.
| Parameter | Hydraulic Skidding System | Hydraulic Walking System |
|---|---|---|
| Movement type | Linear (inline wells) | 360° omni‑directional |
| Minimum well spacing | 5 m (16 ft) | 6 m (20 ft) |
| Maximum rig weight capacity | 1,500 tons | 3,175 tons (3,500 US tons) |
| Stroke / step length per cycle | 580 mm (standard) | 0.9 – 1.8 m (3 – 6 ft) |
| Movement speed | 200 – 600 mm/min | Up to 53 ft/hour (16 m/hour) |
| Hydraulic system pressure | 25 MPa (3,625 psi) | 3,000 – 5,000 psi |
| Single cylinder pull force | 1,100 kN | – |
| Single cylinder push force | 1,570 kN | – |
| Lift height (walking only) | N/A | 50 – 150 mm (2 – 6 in) |
| Ground bearing pressure | 5,000 – 7,500 psf | 7,500 psf max |
| API structural standard | API 4F | API 4F |
| Control system | Wired or wireless pendant | Load‑cell feedback, auto‑level |
| Move time (8m spacing) | 20 – 40 minutes | 45 – 90 minutes |
| Permitted moving load | Empty setback | Full setback + fluids |
| Retrofit to existing rig | Yes – bolt‑on | Yes – bolt‑on |
Types of Offset Drilling Equipment
| Type | Movement | Best For | Key Feature |
|---|---|---|---|
| Short‑stroke skidding | Linear only | Inline cluster wells (single row) | Fastest move speed, lowest cost |
| Full hydraulic walking | 360° omni‑directional | Multi‑row pads, irregular layouts | Any direction, any time |
| Skid + walk combo | Linear + 360° | Large pads with multiple rows | Maximum flexibility |
| Retrofit offset kit | User’s choice | Existing rigs with standard substructure | No new rig purchase needed |
All systems include a hydraulic power unit (HPU), control console, and all necessary hoses, fittings, and mounting hardware. Systems can be permanently built into the base of a new rig or retrofitted to an existing one.
Applications
| Application | Why Offset Drilling Equipment Is Needed |
|---|---|
| Shale gas / tight gas cluster pads (10–50 wells) | Move every 2‑3 days; conventional moves impossible |
| Urban drilling (space‑constrained) | No space for crane‑assisted disassembly |
| Offshore platform slot drilling | Skid between slots – platform deck space limited |
| Batch drilling campaigns | Drill surface holes sequentially, then intermediate |
| Workover campaigns on dense pads | Move between wells in hours, not days |
| Environmentally sensitive areas | One pad, many wells – reduces land disturbance |
Why Choose SJ Petro for Offset Drilling Equipment?
1. Field‑Proven on Thousands of Wells – Our offset equipment has moved drilling rigs on over 1,000 pad drilling jobs. The technology is refined, not experimental.
2. Designed for Real World Cluster Spacing – Many competitors’ systems require 8‑10m spacing. Our short‑stroke skidding works down to 5m, and walking systems handle 6m spacing.
3. API 4F Certified – Full structural certification for all load‑bearing components. Third‑party witnessing available.
4. Retrofit Friendly – Bolt‑on design fits most existing rig substructures. No welding required. Installation in 5‑7 days.
5. Fast Move Times – 20‑90 minutes per well spacing. You finish drilling more wells per month.
6. One‑Person Operation – Wireless remote console allows the driller (or a single operator) to control the entire move. Spotter not required on automated systems.
7. Global Service & Spares – Hydraulic cylinders, control valves, and wear parts stocked in Houston, Dubai, and Singapore. 48‑hour emergency air freight.
8. Sinopec Engineering Backing – Developed with Sinopec’s own drilling division – tested on the world’s largest cluster drilling campaigns.
Frequently Asked Questions (FAQ)
Q1: What is the difference between "offset drilling equipment” and a conventional rig move?
Conventional move: rig‑down → truck → rig‑up (2‑5 days). Offset: skid or walk with mast up (20‑90 minutes). The name "offset” comes from moving the rig off the current well center to the next offset well location.
Q2: Can I use offset equipment on an existing rig, or do I need a new rig?
Most existing rigs can be retrofitted with bolt‑on skidding or walking systems. We require a site survey to measure your substructure and design the mounting brackets.
Q3: How fast can I move between wells on a 5‑well pad?
Skidding: 20‑40 minutes per move. Walking: 45‑90 minutes per move. Total for 5 wells: 2‑4 hours to complete all moves (plus drilling time).
Q4: What is the maximum rig weight your offset equipment can move?
Standard walking systems handle up to 3,175 tonnes (3,500 US tons). Standard skidding systems up to 1,500 tonnes. Custom designs for larger rigs – contact engineering.
Q5: Does the system work on uneven ground or sloped pads?
Yes – walking systems auto‑level using load‑cell feedback, adjusting individual leg heights to keep the rig level. Maximum slope: 10° standard, up to 15° with extended outriggers.
Q6: Can I move the rig with a full load of drill pipe in the setback?
Walking systems permit moving with full setback (pipe in the derrick). Skidding systems are typically used with empty setback. Specify "full load moving” when ordering.
Q7: What API standards does your offset equipment meet?
API Specification 4F – Drilling and Well Servicing Structures – covering structural design, wind loading, and load ratings for all skidding and walking components.
Q8: How many people are needed to operate the offset system?
Skidding: 2‑3 (operator + spotter). Walking: 1‑2 with automated control (one operator, optional spotter). Wireless remote allows the operator to stand at a safe distance.
Q9: Do you provide training for offset system operation?
Yes – 2 days on‑site training covering: system assembly, move sequence, remote control operation, emergency procedures, and daily maintenance checks.
Q10: What is the typical lead time for offset drilling equipment?
Skidding systems: 3‑4 months. Walking systems: 5‑6 months. Retrofit kits for existing rigs: 4‑5 months (includes site survey). Expedited delivery available for emergency retrofits.
Q11: Can you design a combination system – skid on rows, walk between rows?
Yes – our combo systems use skidding for fast inline moves and walking for row‑to‑row travel. Most common on large multi‑row pads (20+ wells).
Q12: How do I get a quote for offset drilling equipment?
Provide: rig weight (tons), pad layout (number of wells, spacing), desired move type (skid/walk/combo), and current substructure photos (for retrofit). We will respond within 5 business days with a system proposal and fixed price.
