Wellhead services, in depth.

IWS installs wellheads and casing heads end to end — setting and levelling the base, landing and tacking the casing head, welding it to the casing under a qualified procedure, and heat-treating the joint so the welded joint is completed to the applicable sour-service requirements and pressure-tight. Work is delivered onshore, offshore and on unconventional wells, to the rig's schedule.

What's involved

• Set-up and levelling of base table and work platform at the rig site
• Landing, alignment and tack of the casing head to the casing
• Preheat, root, fill and cap passes to a qualified WPS
• Controlled post-weld heat treatment and controlled cool-down
• Blast, paint and hand-back with a full documented record

Workover support keeps producing and injection wells in service. IWS recovers and re-installs wellheads and casing heads, carries out casing-pipe butt welding and re-stubbing, and supports rig and platform interventions — onshore and offshore. Every weld that carries pressure or sour-service duty is qualified, heat-treated and documented like any other IWS joint.

What's involved

• Wellhead and casing-head recovery, re-installation and re-termination
• Casing-pipe butt welding and re-stubbing to a qualified weld map
• Hot-tap and injectivity testing across casing strings where required
• Offshore and onshore intervention support to platform and rig schedules
• Controlled preheat and PWHT with a full documented record

The heart of what IWS does. In sour (H₂S) service, the finished weld — filler metal and heat-affected zone included — must retain the base metal's properties to resist sulphide stress cracking. We achieve that with low-hydrogen procedures, controlled preheat, and post-weld heat treatment that relieves residual stress and brings weld-zone hardness back below the NACE limit.

What's involved

• Qualified WPS / PQR for each material and weld type
• Thermocouple-verified preheat and inter-pass control
• Electrical-resistance PWHT with multi-zone pad control
• Calibrated chart-recorder log for every weld
• Bend, macro, hardness and tensile testing to ASME IX & NACE

Cold cutting severs and bevels pipe and casing mechanically — with no flame and no heat-affected zone. A split-frame, air-driven cutter clamps to the pipe outside diameter and produces a lathe-type square or bevelled end ready for welding. Because there's no ignition source, it's safe in live and hydrocarbon environments, onshore and offshore.

What's involved

• Split-frame cutter mounts directly to the pipe O.D.
• Square or bevelled cuts across a wide range of pipe and casing sizes
• No open-flame cutting — safe near live equipment
• Minimal radial and axial clearance required
• Fast set-up, typically operational within minutes

Hot tapping makes a new connection into a pipe, vessel or line that stays live and under pressure — no shutdown, no loss of production. A drilling machine cuts through the wall while a valve isolates the tap, allowing new branches, instrument connections or completion fittings to be added safely.

What's involved

• Connections made without shutting in the well or line
• Tapping across a range of branch sizes
• Isolation valve set so the tap is controlled throughout
• Can be paired with controlled welding of the fitting
• Delivered under procedure with full risk control

A weld is only finished when its quality is proven. IWS verifies the welds it makes — first by pressure-testing the welded section to confirm the joint is leak-tight, then by a documented inspection regime that examines the weld for surface and sub-surface flaws and checks weld-zone hardness against the sour-service limit. The focus is the integrity of the weld itself, not a full wellhead-system test.

Pressure testing — welded section

Pressure testing here is applied to the welded joint, not the whole wellhead system — it confirms that the weld IWS has made holds. The new or repaired section is isolated and brought up to the specified test pressure, then held for the code-required duration to expose any leak before the well returns to service.

• Test applied to the welded joint / section, isolated from the wider wellhead
• Hydrostatic or pneumatic test to the governing construction code (ASME B31.3 / ASME BPVC Section VIII)
• Held at the specified test pressure for the code-required duration
• Pressure-decay monitoring and leak detection across the weld
• Result recorded against the code acceptance criteria

Quality inspection — MPI, UT & hardness

Each weld is examined non-destructively and checked for hardness by technicians qualified to ASNT SNT-TC-1A or ISO 9712, with results assessed against the applicable code acceptance criteria.

• Magnetic particle inspection (MPI / MT) for surface and near-surface flaws — to ASME BPVC Section V Article 7 / ISO 17638
• Ultrasonic testing (UT) for sub-surface and volumetric flaws — to ASME BPVC Section V Article 4 / ISO 17640
• Hardness testing of the weld and heat-affected zone — Vickers to ASTM E92 / ISO 6507
• Weld-zone hardness verified below the NACE sour-service limit (≤ the applicable NACE MR0175 / ISO 15156 and client hardness limit) per NACE MR0175 / ISO 15156
• Full inspection record compiled and handed to the operator

Beyond installation, IWS repairs wellhead and casing-head equipment in the field and fabricates to spec — skids, frames, supports and made-to-drawing assemblies — plus rig modifications and workover support. Wherever a weld carries pressure or sour-service duty, it's qualified, heat-treated and documented like any other IWS joint.

What's involved

• In-field wellhead and casing-head repair and remediation
• Custom fabrication built to drawing and welded to code
• Rig modifications, upgrades and structural work
• Offshore and onshore workover support
• Qualified welders, inspectors and NDT/PWHT technicians