Offshore workover technology

Technical Specifications – SOFE Offshore Workover Technology

Platform Workover Rigs – HXJ Series (Representative)

Parameter	HXJ135	HXJ180	HXJ225
Rated hook load (kN / tons)	1,350 kN (135 tons)	1,800 kN (180 tons)	2,250 kN (225 tons)
Mast type	Two‑section telescopic, front‑opening	Two‑section telescopic, front‑opening	Two‑section telescopic, front‑opening
Mast height (metres / feet)	33 m (108 ft)	35 m (115 ft)	39 m (128 ft)
Mounting	Skid‑mounted (custom deck interface)	Skid‑mounted	Skid‑mounted
Workover depth (2-⅞″ tubing)	Up to 5,000 m	Up to 7,000 m	Up to 9,000 m
Traveling system	4×5	4×5	5×6
API compliance	API 4F, 7K, 8C, Q1	API 4F, 7K, 8C, Q1	API 4F, 7K, 8C, Q1
Coating system	ISO 12944 C5‑M	ISO 12944 C5‑M	ISO 12944 C5‑M

Hydraulic Workover (Snubbing) Unit – Capacity Ranges

Capacity Class	Pulling (lbs)	Snubbing (lbs)	Tubing Range (in)	Rotary Torque (ft·lbs)
150K	150,000	66,000	1 – 2-⅞″	5,000
225K	225,000	120,000	1 – 5-½″	5,000
340K	340,000	188,000	1 – 7-⅝″	10,000
460K	460,000	220,000	1 – 8-⅝″	10,000
600K	600,000	260,000	1 – 8-⅝″	20,000

Product Types – Offshore Workover Technology Configurations

1. Platform Workover Rigs (HXJ Series)

Skid‑mounted conventional workover rigs for fixed platforms. Designed for tubing change‑out, ESP replacement and well maintenance when the well is dead (no surface pressure). Available in 135‑ton, 180‑ton and 225‑ton hook load capacities.

2. Hydraulic Workover (Snubbing) Units

For live well interventions where surface pressure prevents conventional rig operations. Units push pipe into the well against pressure using hydraulic jacks and a BOP stack. Available in pulling capacities from 150,000 to 600,000 lbs.

3. Coiled Tubing Packages (Skid‑Mounted)

Containerised or skid‑mounted coiled tubing units for well cleanout, milling, acidizing and scale removal before or after workover. Real‑time tension control and depth logging integrated with platform control system.

4. Cementing & Stimulation Fleets

Skid‑mounted cementing units and fracturing packages for offshore use. SOFE’s cementing unit is the only China‑made product operating on the HD‑981 deepwater semisubmersible platform.

5. Integrated BOP & Control Systems

Pre‑assembled BOP stacks (single or dual ram, annular) with remote hydraulic control panels designed to interface with platform HPU and ESD systems.

6. Offshore Well Intervention Kits

Complete intervention packages including workover rig, snubbing unit, coiled tubing, fishing tools, downhole motors and milling tools – all supplied under one SOFE quality management system.

Application Fields – Where SOFE Offshore Workover Technology Operates

Fixed Platform Slot Drilling & Workover

On platforms with multiple well slots, the workover rig skids from slot to slot, performing ESP replacement, tubing change‑out, scale removal and zone isolation without demobilising the rig. SOFE’s HXJ units are deployed across the Bohai Sea, East China Sea and South China Sea.

Live Well Snubbing – Platform & Jack‑Up

When reservoir pressure is high and kill fluids are impractical or damaging, hydraulic snubbing units push pipe into the well against surface pressure. A modular HWO system has been shown to execute heavy workover operations in space‑constrained offshore environments with coordinated logistics across vessel and platform teams.

Subsea Well Intervention (Riserless & Riser‑Based)

For subsea completions, intervention is often performed from monohull vessels using riserless or riser‑based workover systems. SOFE has more than 30 years of offshore engineering experience and has produced ROV‑compatible subsea well systems and subsea well factory equipment.

Deepwater Semi‑Submersible Support

SOFE’s cementing unit has been successfully operating on the Deep‑water Semisubmersible Drilling Platform (HD‑981) , demonstrating its capability to support deepwater drilling and completion campaigns with integrated equipment packages.

Remote & Electrically Driven Workover

In the latest industry push toward lower emissions, hybrid and fully electric workover units are emerging. SOFE’s electric fracturing equipment and power distribution technologies are now being adapted for offshore workover, reducing fuel consumption and platform emissions.

Why Choose SJ Petro / Sinopec Oilfield Equipment for Offshore Workover Technology?

30+ Years Offshore Experience – 400+ Units Delivered

SOFE has more than 30 years of offshore equipment manufacturing experience and has produced more than 400 sets of large‑scale offshore equipment widely used in the Bohai Sea, East China Sea and South China Sea, and exported to North America and Malaysia. This is not theoretical capability – it is field‑proven performance.

Full API Certification – 4F, 7K, 8C, 6A, 16C, Q1, Spec 7‑1

All SOFE workover technology is designed and manufactured in accordance with API standards, with annual audits maintaining certification validity. Complete documentation – material test reports, NDT records, pressure test certificates – is included with every shipment.

Integrated Intervention Ecosystem – One Manufacturer, One Quality Standard

SOFE does not sell workover rigs in isolation. The company’s 16 production lines cover drill bits & tools, drilling & workover rigs, coiled tubing, snubbing units, cementing & fracturing fleets, high‑pressure fluid control products and steel pipe. One manufacturer. One quality standard. One warranty. One service contact.

Global Offshore Track Record – 40+ Countries

SOFE has exported products to more than 40 countries and regions, with 5 subsidiaries in the United States, Japan, Germany, Russia and the UAE, and 8 offices in Brazil and other key markets. For offshore operators, this means local support and spare parts where they are needed.

Independent R&D – HXJ Series & 10,000‑Metre Workover

Since 2019, SOFE has independently developed various offshore workover rigs – HXJ135, HXJ180 and HXJ225 – named after their maximum tonnage. Most recently, the newly developed XJ2750 10,000‑metre truck‑mounted workover rig has entered China's 10,000‑metre‑deep workover era, demonstrating the same engineering capability applied to offshore platforms.

Third‑Party Inspection & Marine Certification Ready

SOFE has established a third‑party inspection, testing and calibration service lab with independent legal status, accredited by CNACL. All equipment can be supplied with classification society certification (ABS, DNV, BV, CCS) as required.

Frequently Asked Questions (FAQ)

Q1: What is the difference between a platform workover rig and a hydraulic snubbing unit?

A: A platform workover rig (HXJ series) is a conventional rig – mast, drawworks, rotary table – used when the well is dead (no surface pressure). A hydraulic snubbing unit uses hydraulic jacks and a BOP stack to push pipe into or pull pipe out of a live well against surface pressure. The same SOFE technology family includes both, and some hydraulic units can be used in both modes depending on well conditions.

Q2: Can your offshore workover technology operate on a platform with limited deck space?

A: Yes. SOFE’s HXJ units are skid‑mounted with custom deck interfaces. We have delivered units to platforms where the available deck area was less than 200 square metres, using cantilevered mast designs and off‑deck control cabins.

Q3: What API standards do SOFE offshore workover rigs meet?

A: SOFE workover rigs are designed and manufactured in accordance with API Spec Q1, 4F, 7K, 8C and RP500, as well as GB3826.1, GB3836.2, GB7258 and SY5202. Hydraulic snubbing and coiled tubing units additionally meet API Spec 16B and 16ST.

Q4: How does snubbing technology work in a live well?

A: Hydraulic jacks provide downward force to push pipe into the hole against surface pressure. Stripper rubbers in the BOP stack seal around the moving pipe. Load cells compare string weight to wellhead pressure; when string weight exceeds upward expulsion force, the unit automatically transitions to hydraulic workover (pulling) mode.

Q5: Do you provide third‑party certification for offshore workover equipment?

A: Yes. SOFE welcomes third‑party inspection by ABS, DNV, BV, CCS or any certified agency. Our independent test lab is CNACL‑accredited. Classification society certification can be included in the quotation.

Q6: What is the typical lead time for a complete offshore workover package?

A: Lead time depends on configuration and customisation: platform workover rig (HXJ) – 8–10 months; hydraulic snubbing unit – 6–8 months; complete intervention package (rig + snubbing + coiled tubing) – 12–14 months. We recommend engaging SOFE 18–24 months before planned offshore intervention to allow for engineering, fabrication and classification approvals.

Q7: Does SOFE offer remote monitoring for offshore workover operations?

A: Yes. The SOFElink® intelligent control platform provides real‑time data – hook load, jack pressure, pump rates – to shore‑based engineers via secure satellite link. This enables remote diagnostics, intervention support and predictive maintenance.

Q8: How do I request a quote for an SOFE offshore workover unit?

A: Please provide the following information to our export sales team:

1. Platform type (fixed, jack‑up, semi‑submersible) and deck layout

2. Wellhead pressure (psi / MPa) and H₂S/CO₂ content

3. Required pulling / snubbing capacity (tons or lbs)

4. Maximum well depth (metres)

5. Auxiliary equipment needs (coiled tubing, cementing, BOP stack)

6. Classification society requirement (ABS, DNV, BV, CCS)

7. Desired delivery date

We will respond within 3‑5 business days with a technical proposal and firm price quotation.