Super Single Work-Over Rigs

getAttribute('page_type') == 'news-events'){ ?>


Super Single Work-Over Rigs

Nordic has a vast range of services to offer, and will during the next years concentrate on developing tailor-made drilling and well intervention solutions for its customers.

In addition to the company's current operations, and based on market needs, new technological solutions and concepts are to be prioritized and developed such as

  • Nordic Super Single Rigs technology
  • Slim-hole drilling
  • Coiled Tubing Drilling
  • Under-Balanced Drilling
  • Continuous Circulation Manifold
  • Production Enhancement Tools


Introduction to the Nordic SSR 450 Series

The use of hybrid work over and snubbing rigs for drilling applications is a new phenomenon made possible by the development of number of enabling technologies.

These include enhanced rig designs, pipe handling systems to aid in tripping efficiencies with single joint rigs, reliable slim-hole drilling MWD technologies, top drive systems with torques reaching 25,000 ft/lbs and tailor made window cutting system among others. In addition there is an increasing business imperative to maximize recoveries from existing assets and to a develop technologies that will make marginal fields economic. This has challenged the service industry and operators to develop and utilize non conventional drilling and completion techniques.

This document describes a unique modular rig that has been built for drilling, work over and snubbing capabilities using jointed pipe.     
The expansion of underbalanced thru-tubing interventions, work over’s and re-entry drilling has led to a need for multi-purpose rig specifically designed to perform traditional underbalanced rig-less well operations combined with standard work over rig work.

A hybrid rig specifically designed to conduct traditional rig operations combined with the ability to switch to underbalanced thru-tubing applications has now been developed by Nordic and has been aptly named the Snubbing & Work Over Rig or “SSR 450 Series”.

The concept of the SSR 450 Series evolved from innovative engineers in conjunction with experiences drilling, work over and snubbing personnel from Nordic. By combining underbalanced horizontal drilling experience and mobile land based rig design expertise with snubbing and well control know how, a new specialized work over and snubbing company has been formed.

With a unique modular concept, Nordic has bridged the gap between a drilling rig and a rig less well intervention unit. Up till now the use of single joints (i.e. 30 ft or greater) for well intervention and/or snubbing operations has been restrictive due to design of standard units and the prohibitive cost effectiveness of handling larger diameter drill pipe sizes. The rig concept developed by Nordic, is allowing a rig up time of 3 to 4 hours and a tripping speed of 3000 ft per hour in live wells. This new design also allows for continuous circulating while tripping pipe thus improving safety during underbalanced drilling and/or high pressure fracing and stimulation operations.

This document describes a modular rig that has been manufactured specifically for bridging the gap between a traditional drilling rig and a rig less intervention unit. The unique design allows the SSR 450 Series to perform all aspects of a work over operation and snubbing/well intervention work.

The SSR 450 Series has been manufactured fulfill the following scope of work for re-entry drilling and side-tracking operations both overbalanced and underbalanced:

  • Run/Pull production tubing
  • Cut window
  • Run and set whip stocks
  • Run or pull casing liners and completions
  • Build curves and drill horizontal and directional wells.
  • Drill under balanced and run and pull completions in live wells.

Further the SSR 450 Series can perform the following snubbing and well intervention operation without any modifications to the rig:

  • Run/Pull ESP pumps
  • Re-completions
  • High pressure stimulation in long horizontal wells
  • High pressure fracing
  • Thru-tubing fishing in live wells
  • Thru-tubing milling in live wells
  • Well control
  • Well killing


SSR 450 series - Design Criteria

The SSR 450 series has been designed using extensive experience gained in both drilling, work over and snubbing operations. The effectiveness of conventional snubbing units to drill in an open hole efficiently was questioned. In the latter case, market expectations exceeded the capabilities of conventional technology.

The SSR 450 was designed in conjunction with operational and Health safety and Environmental (HSE) suggestions from a number of operations to overcome these technical and hence economic hurdles. The major design criteria were:

  • Modular constructions for use both onshore and offshore
  • Fast rig up (3 to 4 hours) and easy to move
  • Self-erecting ( no need for cranes or rig moving company’s)
  • Easy deployment of BHA under pressure. (no need for high pressure riser)
  • Capable of operating underbalanced or overbalanced with no modifications to the Rig lay-out Minimize crew levels
  • Maximize the range of applications for which rig was competitive such as re-entry and side-tracking drilling, work-overs and live snubbing operations
SSR 450

SSR 450, a fully self contained hybrid rig capable of operating using jointed pipe for re- entry/light drilling, work over and snubbing applications. Unique in the design of SSR 450 is the integration of surface control system to improve process efficiencies and reduce the crew requirement. The combination of mechanized pipe handling system and continuous circulating systems and the use of multiskilled crews have lead to improved economics over conventional units.

The SSR 450 includes the following modules:

  • Mast, substructure and prime mover unit
  • Pipe handling and hydraulic Catwalk machine.
  • Drilling fluids units
  • Mud pump units
  • Generator unit

The key features of the SSR 450 which will be further described in this document are:

  • Eliminations of a lubricant for deploying bottom hole assemblies (BHA) in live wells.
  • Continuous Circulating System
  • Dual pipe handling
  • Multiskilling of the crew.

Operations Envelope

Currently, the applications best suited for the SSR 450 rig are those associated with light drilling/side-tracks, work overs and under balanced snubbing/well intervention operations. The benefits of the SSR 450 rig are particularly well realized in underbalanced thru-tubing operations such as: acid pumping, thru-tubing fishing, P&A operations etc.

Hosting System

Over the last few years, the types of rigs that have been utilized to drill wells have increased. Units have been built incorporating the hoisting method of a standard rigs, rack & pinion system and the hosting method of snubbing units.

The SSR 450 has combined the hoisting methods but also included the hoisting method of a standard drilling rig. ( i.e Mast structure) The idea behind this design was to simplify the handling of tubulars.
Jointed pipe is handled by the derrick with standard tools and standard procedures.

The snubbing ability is primarily used for handling tubulars in live well situations where the tubulars need to be snubbed into the well.

Continuous Circulating System

The Continuous Circulation Manifold (CCM) allows all fluid circulation to be constantly maintained while making connections with conventional pipe. The CCM makes continuous circulation during connections possible by creating a sealed pressure chamber around the tool joint to be broken. Pressurized fluid is introduced into this chamber equalizing the pressure inside and outside of the connection.

The CCM is designed to work in conjunction with the rigs rotary table and top-drive and is a self-contained unit that also can be installed on almost any top-drive equipped rig in a matter of hours. Continuous fluid circulation creates the conditions needed to maintain constant bottom-hole pressures resulting in enhanced work-over operation performance while reducing non-productive time. It allows long stroke SSR 450 series rigs to safely perform under balanced drilling, acidizing, and safely use compressible fluids on a continuous basis.

Perforation Enhancement Technology

Nordics Thru Tubing Perforation Enhancement Tool (PET Tool) can mill an exit window in the casing and then drill a 2-3/8” to 2 7/8” perforation tunnel 12 ft. into virgin formation at an angle of 35 degrees. The tool can be run on Nordic’s SSR 450 series Rigs, Coil Tubing or Joint Pipe and increases the flow area by 2000% compared to perforation guns

Technical data - Nordic’s 200 ton SSR 450 series rigs

Overall Height: 22.00 m
Overall Length: 6.00 m
GL to Drillfloor: 5,0 m

Drilling Equipment

Mast: Telescopic Mast
Rackingcap: Lay down
Hoisting window: 55 feet stroke
Maximum Pull capacity: 440,000 Lbs (200 ton)
Hoisting system: 3 X hydraulic cylinders X sheaves and cables
Maximum Push capacity: (Snubbing) 100K Snubbing force w/ Lock Down
Top Drive: Depro – 25.000 Ft/lbs @ 150 RPM continuous
Rotary table: 17-1/2 inch
Pipehandling: Remote operated from rig floor
Tripping speed: 3000 feet per hour
Iron Roughneck: Farr Tubing tong
Drillers Control: Depro Design
Instrumentation: Depro Design
Mud Pumps: 2 X 700 HP
Solids Control:  2 x double deck MD shakers, De-sander, De-silter

Power Equipment

HPU:    210 Bar / 3000 PSI / 900 HP

Storage capacities

Mud system: 1200 Barrels Liquid capacity

BOP Equipment

Diverter:  N/A
BOP Stack:
7 1/16” or 13” x 5K Annular, 1 Double and 1 Single Ram

Special Features


HSE: Hands Off Operation & Handling due to remote operations.
Snubbing: No re-rigging when Snubbing is required.
Crew: 12 men crew for 24 / 7 operations
Rig Move: Basic Rig with Mast – 9 Truckloads

Dual pipe handling system

Conventionally, HWO Rigs’s have utilized a cable handling system (Gin Pole) for transferring a tubular such as drill pipe or casing from the pipe rack. A cable extends from the gin pole and is attached to the selected pipe or tubular on the pipe rack. The tubular lies in a generally horizontal position, box end forward, such that the box end of the pipe is initially pulled from the pipe rack by the cable up the catwalk of the rig and through the V-door to assume a substantially vertical position above the drill floor. The lower end is installed into the tool joint connection of the previously transferred pipe and the cable is disconnected.

There are several disadvantages inherent in the conventional cable handling. It is slow and the manual involvement of attaching the head of a cable to the tubular and the subsequent movement of the pipe during the transfer operation in the vicinity of a worker gives rise to dangerous working conditions and     
pipe handling is a major source of injuries. As the tubular is transferred from the pipe rack to the drill floor utilizing the cable, contact between the tubular and the catwalk or other portions of the rig is made which can cause damage to the tubular and affect the integrity of the connection between successive ones of the tubulars.

The Dual Pipe Handling System move the tubular from a horizontal position on a pipe rack adjacent to the wellbore to a vertical position over the well centre. The movement is done in two stages, where the first one is to push the tubular up and in line with the V-door. The next step is that the pipe handling arm that lays parallel with the V-door grabs the tubular and in one movement rise up into vertical position over the mouse hole. Since there are two arms the second tubular will be pushed up into parallel with the V-door and grabbed by the second pipe handling arm while the first one is standing in upraised position over the mouse hole. The second arm will go up into vertical position over the mouse hole with the tubular at the same time as the first one is going down to get the next tubular.

Nordic Dual pipe handling system solution makes pipe handling safer compared to conventional cable solutions, but most important, it is considerably faster than any other pipe handling systems on the marked today and will contribute to a safe and more efficient operation when combined with Nordic’s SSR 450 series rigs.

Also have a look at our other


  • Work Over & Snubbing Rigs

    An increasing number of oil and gas companies are using snubbing & work over rigs as a routine procedure for P&A, well completio…

    Coiled Tubing

    Coiled tubing operations often require large pulling capacity due to long horizontal wells. Operations in these types of wells i…

  • Nitrogen Services

    Nordic has a fleet of nitrogen pumpers with pumping capacities ranging from 90K scf/min to 180K scf/min and with pumping pressur…

    Thru Tubing Tools

    Nordic has a specialized thru tubing intervention division whom are experts in custom made solutions to solve any down-hole prob…


in the





30 September 2018


NORDIC joins GOTECH (Gas & Oil Technology) Showcase and Conference 2018 on October 22-24, 2018 at the Dubai World Trade Center. Have a look at our Exhibition Stand at Booth No. GO013 at the Sheikh Maktoum Hall.

read more




15 June 2014

New website

The 15th of June Nordic's new website has been launched. With a new fresh look and feel you can now easily browse our services and keep up to date on events. The gallery gives an impression of how our Nordic services find place. If you are interested in getting in touch with you, please fill out the contact form on the contact us page and we will be in touch with you shortly. Enjoy our website.

read more

in the spotlightin the news

request more



Nordic Energy FZC
Office No. 106
Bay Square Building

Business Bay
PO Box 93086, Dubai
United Arab Emirates

Click here for location


T +971 4 876 7654

Get in touch

call me back