The multi-disciplined service provider to
the oil and gas industry in Kazakhstan
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Our services are provided to clients throughout the lifespan of their projects, covering construction, commissioning, maintenance and decommissioning. We pride ourselves on meeting our key deliverable of finding solution-focused results, whilst realising our clients’ needs for cost and schedule delivery.

Shutdown Support
shutdown support
shutdown support


  • Denholm Zholdas have successfully carried out the turnarounds and shutdowns for TCO for 10 years. We have been awarded several recommendation letters from TCO for our reliability and excellent service.
  • A workforce of over 900 on site during Tengiz turnaround
  • We were awarded the Shutdown contract for KPO in 2008 and have successfully competed the shutdowns on time and schedule for the last 2 years.
  • Up to 600 people on site during KPO shutdown.


  • Scaffolding
  • Pipe fitting and welding
  • Industrial Cleaning
  • Insulation
  • Fireproofing
  • Plant hire
  • HVCC Metal Spray (AmStar)
  • Valve Maintenance
  • HT and NDT
  • Material Handling
  • Mechanical Services
  • Hydrotesting
  • Machining
  • Fabrication
  • Leak Sealing
Maintenance Services
  • maintenance services
    Denholm Zholdas have been the primary maintenance service provider to TCO since 2005.
  • At any one time there are between 300 and 400 personnel on site, all year round.
  • All required equipment, products or consumables can be supplied for all maintenance needs.
  • As with the Shutdown support services we can provide a full range of services to meet all maintenance requirements, with a pool of up to 1600 well trained personnel. Whatever the need, whatever the schedule DZ will rise to the challenge.
Valve and Mechanical Services

Valve Operations

valve and mechanical services
valve and mechanical services
valve and mechanical services

Denholm Zholdas have since 2001 been the sole provider of valve maintenance at the TCO site. We have carried out calibration and full maintenance service for TCO on over 11,000 valves in 2008, ranging in sizes from ¼” to 70”, and up to 400 BARG.

DZ have mobile containerised workshops available for site work.

DZ designed and implemented our own database and certification system (MaintainIT tm) that can be used by the client to allow data to be collated for regulatory departments.

Currently under construction is a 4500m2 facility to maintain, calibrate and overhaul all sizes and types of valves, in addition to being a complete mechanical workshop offering our complete range of services.

Range of Mechanical Services

  • Leak sealing
  • On site machining
  • Bolting services/joint management
  • Composite repair of pipelines/vessels
  • Pipeline intervention, flow stopping
  • Hot Tapping services
  • Valve maintenance, repair, calibration and certification
  • Valve and Valve spare parts supply
  • Mechanical seal maintenance/repair
  • Mechanical seal supply
  • Computerized Valve monitoring and diagnostics


  • Denholm Zholdas is the most dynamic scaffold company in Kazakhstan. Beginning in 1999 this group was formed to bring International Standard Scaffolds to the ROK workplace. Continually improving to meet and exceed local & International regulations this group are locally certified and internationally trained in a variety of access solutions and can support Construction and Maintenance projects nationwide.
  • We have carried out both large and small scale works on various sites, using both conventional and system scaffolds.
  • We have recently introduced Delta System scaffolding to our range of products, which is one of the highest specification, easiest to erect/dismantle system scaffolds available on the world market, and we have brought it to Kazakhstan.

Denholm Zholdas have been installing insulation for 10 years on various sites, with Tengiz being the main field of operations for this activity.

We have a highly trained and skilled workforce, able carry out a full range of work scopes, whether it be in the workshop or in the field.

Main insulation products used are rockwool based insulation material/products, with a steel or aluminium jacketing.

Since the co-operation with Beerenberg, we now have more specialist ranges of insulation to our services and product list. Of particular note is the patented Benarx product line – an extremely high specification product which can be made to measure – and is capable of being installed and removed time and time again without any damage to the product or performance. This is particularly important when access to valves/flanges or inspection points are required.

Fire proofing

Denholm Zholdas have an agreement in place with Beerenberg Corp. AS (formerly D&F Group). Beerenberg are leaders in the field of fireproofing and specialist insulation. Beerenberg are one of Aker’s main contractors in the Norwegian Market.

Through this alliance Denholm Zholdas are able to provide the expertise of Beerenberg combined with DZ’s core of well trained local labour to achieve high standards of quality combined with fast productivity, and great flexibility.

We are able to provide the full solution including all application equipment, access requirements, all manpower including QAQC inspectors.

A recent recommendation from the greenfield area manager of KPO stated:

Denholm Zholdas’ fireproofing division have shown their ability to produce quality workmanship under pressure and in difficult site conditions. With no incidents to date and planned stage completion targets being met we are continuing too, and would not hesitate too use DZ fireproofing division in the future.

DZ have also shown they hold the correct equipment and experience with both expat and local personnel.”

Vessel Cleaning and HPWJ
Vessel Cleaning
Vessel Cleaning
  • Denholm Zholdas have been carrying out High Pressure Water Jetting in Kazakhstan for over 10 years.
  • Denholm Zholdas have over 130 trained jetting operatives in Kazakhstan.
  • Many operations include confined space entry, which our operatives are fully trained in the safe operation of activities, and we provide specialist HSE personnel to ensure safe operations.
  • Jetting works to all types of vessels, including maritime shipping, at:-
    • TCO - Tengiz
    • KPO - Aksai
    • Agip - Bautino
    • Saipem - Island D
    • CMOC - Bautino

Welding and Pipe Fitting

Denholm Zholdas Welding Group have a full range of welding capabilities and support clients with maintenance and construction contracts. Confidently undertaking all manner of welding processes our welders are ROK qualified and of the highest standard.

Our welding operations are carried out in accordance with independently approved Weld Procedure Specifications (WPS) and Weld Procedure Qualification Records (WPQR).

  • We cover a range of materials from conventional carbons, steel tube, plate, through to super-duplex and stainless steel applications.
  • Our welding and fabrication capabilities cover:
    • Manual Metal Arc (MMA)
    • Tungsten Inert Gas (TIG)
  • One of or our recent projects we had a team of welders 12 who managed a 0 repair rate on carbon steel pipelines for 18 months whilst consistently outperforming our competitors on daily Diameter inches.
Blasting and Painting
Blasting and painting
Blasting and painting

Denholm Zholdas have the latest Application and Coating Inspection Systems. We have fully NACE qualified personnel and Inspectors and can supply the most technically advanced products for any type of service from corrosion protection to extreme service shielding.

Denholm Zholdas offers a full range of surface preparation techniques including wet and dry grit blasting, mechanical preparation and Ultra High Pressure water jetting, all performed to internationally accredited standards.

Denholm Zholdas have an excellent track record in the provision of services involving the surface preparation and application of the following protective coating systems:

  • Industrial Epoxies, Alkyds and Urethanes
  • Passive fire-proofing
  • Anti-fouling and Anti-skid Deck Screeds
  • Tank and Vessel Glass Flake Systems
  • Epoxy, Coal Tar and Oil Based Systems
  • Arc and Flame Sprayed Systems
  • Water Based and Solvent Free Systems
  • Galvanizing Systems
NDT and Heat treatment

NDT Heat Treatment

Conventional Inspection

  • Radiography (RT) X-ray
  • Gamma Ray
  • Ultrasonic (UT)
  • Magnetic Particle (MT)
  • Penetrant (PT)

Advanced Inspection

  • ToFD
  • Phased Array Ultrasonic (UT)
  • TFM
  • Scar
  • GUL
  • PMI
  • Welding Preheat
  • Post Weld Heat Treatment (Sub-Critical)
  • Heat Treatment (Super-Critical)
  • Internal Vessel heat treatment
  • Refractory Dry-out
  • Process Startup
  • Temporary Furnace applications
  • Line Thaw – product melt out
  • Hydrogen Removal
  • In house ROK training


Some Notable Achievements:

  • Default Inspection and Heat Treatment subcontractor for PFD contract for SGI and SGP project, 352,000 man-hours without LTA
  • SGI and SGP project Tengiz provided both pre heating and post weld heat treatment services for PFD on the (4) largest ever vessels to be delivered to Kazakhstan
  • Largest ToFD project in the world completed between n 2005 and 2008, with over 37,600 man-hours.
  • Introduced the key advanced inspection services, SCAR ToFD, TFM, GUL, Phased Array to the ROK market
  • Developed through its own in house training programs and have trained and certified our team of over 126 National technicians in heat treatment and inspection services since 2003
Plant Hire


plant hire
plant hire
  • A vast range of equipment at your fingertips with a fleet in excess of 1000 units
  • State-of-the-art products


  • “A professional supplier ready to help”
  • Availability: equipment when you want it
  • Flexibility: short, medium or long term rentals
  • Proximity: rental suppliers close to your work sites
  • Equipment delivered to where you need it
  • Expert advice, not just equipment

Safe & Secure

  • Equipment that complies with regulations
  • Safety checks before each delivery
  • Well maintained products



Denholm Zholdas are not only a services and rental company…


BelzonaWe have an exclusive distributorship agreement with Belzona for the territory of Kazakhstan. Belzona manufacture extremely high specification and quality coatings and repair composites.



BenarxThrough our cooperation with Beerenberg Corp. AS we can provide the Benarx range of products in the Kazakh market. These are patented, high specification, long lasting products that can be made to measure.



MillerOur plant hire division has a JV with Red-D-Arc (owned by Airgas) who are one of the major players in welding machines in the North American market. Denholm Zholdas solely stock Miller machines and consumables, if you need Miller equipment and we don’t have it – we can get it.


Delta Systems

Delta SystemsWe have teamed up with Delta System AS to bring a new aluminium system scaffold to the Kazakhstan market. This is an incredibly fast erect/dismantle, high performance lightweight system scaffolding that offers a wide range of access solutions that weren't available before.