Nimway® is our high capacity, quick make-up riser connector, designed for CWOR (completion & workover riser) applications.

Nimway’s novel tensioned sleeve design evolved from SRP’s experience designing high pressure dynamic flanges: the array of tightened bolts in a conventional flange is replaced by a single stretched sleeve. Preloading is achieved by applying direct hydraulic force and the sleeve is locked in place with the collar.

  • Full preload.
  • No torque.
  • No galling.
  • No error.

All functions are automated on SRP’s spider and make-up tool, which maximises safety and enables an equivalent make-up speed to a threaded connector.

Qualifications & design path

  • 5″ and 7″ 10ksi API Spec 17G WD7 Qualified (full Annex I testing)
  • Open water and in-riser CWOR, with designs and qualification plans to ISO 13628-7, API 17G and API TR8 for 5” and 7” up to 20ksi in water depths to 3,000m.
  • High pressure drilling riser connector for 19.25″ and 15ksi WP operation.
  • Nimway provides the security of a flange but with far fewer components and simplified make-up. The connector is being developed further for high pressure and dynamically loaded permanent subsea connections.



  • Dual bore
  • Single bore
  • Non-rotating connection
  • Quick make-up
  • Stronger than the pipe
  • Large internal drift, limited external drift
  • High bending locations
  • Metal-metal seal and dual elastomer backup
  • Available as weld on or integrally forged
  • Also available as a crossover from your preferred T&C connection


  • Repairable Inconel weld clad seal pockets
  • Replaceable Inconel seal ring
  • Replaceable fasteners
  • Fully compliant with NACE / ISO 15156-2
  • Nimway is not torqued, giving +/-2.5% make-up accuracy (10x better than T&C or drillpipe connections)
  • Virtually unlimited make/breaks.
  • Low geometric SAF (2.5) for enhanced fatigue life.
  • 2 minute make up using SRP’s automated spider and make-up tool
  • Up to 90ft welded riser joints, so only one third of the connections

NIMWAY is patented technology under European patent EP2831478 B1 and U.S. patent 9,650,845.
NIMWAY is a Registered Trade Mark of Subsea Riser Products Limited.

Sealed Wear Casing

Along with our standard gated cased wear joints (CWJ) for completion and workover risers (CWOR), we offer a sealed wear casing, which greatly improves rig floor safety in the event of riser string failure.

The sealed cased wear joint seals on both riser pipe and umbilical lines along the full length of the wear casing, enabling the rig diverter system to safely vent gas away from the rig floor in any position even with heave compensation active.

Interlocking modules enable construction of any length wear casing. Each module is split axially, enabling assembly to any riser joint; and the hinged doors can be quickly closed and fastened vertically on critical path.

The sealed wear casing offers a step change in rig floor safety with comparable running speed of traditional cased wear joints.


  • Completion workover risers (CWOR)
  • Drillstring risers (DSR)
  • Compatible with all riser systems including T&C, forged or union nut connectors
  • Available with integrated joint and our extreme capacity Nimway® connectors


  • Mitigate risk of hydrocarbon leak to rig floor in the event of riser or SSTT failure
  • Trapped fasteners prevent loss downhole
  • Modular design suit any length wear casing
  • Steel construction offers high lateral load capacity with no umbilical crush
  • FEA checks against 100 year storm condition


Typical application dimensions are in the table below, we can design and fabricate to your specification.

Drift outer diameter483mm (19″)
Umbilicals / annulus linesUp to 3 * 65mm OD
CWOR pipe OD (casing ID)265mm (10.4″)
Module length1500mm (60″)
Bending moment capacity500kNm
  • Gas and hydro leak rate tested
  • Zero leak rate specification optional

Riser flanges

SRP has developed a number of large diameter flange designs for high pressure riser applications, including shallow water jack-up and deepwater dry-tree drilling risers.

We offer riser optimised designs with enhanced bending capacity and sealing performance in dynamically loaded applications based on:

  • API Spec 6A.
  • Compact Flanges (NORSOK L-005).
  • Customer specification.

All our designs are designed and independently verified to comply with the requirements of API RP 2RD or ISO 13628-7 in terms of material utilisation limits and sealing capacity.
Our proprietary flange designs have seen extensive use in the North Sea since 2008 in different drilling risers in applications to 15,000psi working pressure.
Through our experience in developing and running high pressure riser systems in the North Sea with our sister company Claxton, we can offer a number of design features for faster running and reliable make-up. Typical features include:

  • Full 3D finite element analysis (FEA).
  • Fatigue qualification testing and FEA correlation.
  • Fastener and bolt tensioning designs for easy spidering and faster rig floor handling.
  • Internal handling grooves for remotely operated running tool.
  • A range of metal sealing options based on industry standard and wellhead bore seals.

We can supply flanged riser joints in fully forged and fabricated joints. For details on our riser joint construction experience, please refer to the project services page.


  • Shallow water subsea wellhead jack up drilling
  • Dry tree systems, including tension leg platform (TLP) drilling risers


  • High reliability: our flanges feature replaceable metal bore seals, high make-up accuracy and enhanced fatigue life for maximum reliability in surface BOP drilling.
  • Optimised solution for your application: whether you want a weight saving slim flange or a workhorse with the fewest bolts, we can offer the right riser flange for your application.
  • Lowest lifecycle cost: with comparable capital costs to other large diameter mechanical connectors, our flanges offer significantly lower lifecycle cost, owing to repairable seal faces and replaceable seals and fasteners.


SRP’s hydraulically actuated riser spider has been used to successfully deploy, retrieve and hang-off risers during one year storms in the North Sea.

The spider is a low profile sliding plate design to give maximum operator visibility and has been designed and tested in accordance with API Spec 7K. All features are remotely controlled on the HPU and control panel, including separate actuation and position locking functions, which give clear visual feedback.

The base design fits into the master bushing shoulder in a 49.5” rotary table and retains the full through bore of the rotary. Adapters to larger 60” rotary tables are available and we can also scale up the design for larger pass through diameters.

The spider is split along the centre to allow removal / installation around a riser joint positioned through the rotary.

The spider is supplied complete with a free standing combined hydraulic power pack and control panel, which features all 316L hydraulic components and an ATEX zone 1 rated air motor.

As an option, the spider can be supplied with alignment gates, which act as an automatic stabbing guide.


  • Deployment and retrieval of risers (particularly drilling risers) from any offshore vessel


  • Safe and field proven design: low profile for maximum visibility, non-slip access surfaces, clearly visible locking pins, and 5 year field history in the North Sea.
  • Robust and flexible design: adaptable to a range of rotary tables with interchangeable key plates; the spider is dual qualified design and manufacture to API Spec 7K and API Spec 8C (13535) to 300t SWL (higher load ratings available).


Our bolsters provide maximum safety during handling, transport and storage of large riser joints; preventing damage to riser monitoring systems, buoyancy and the joint itself.

ISO container locks provide a secure and quick mechanical lock for stacking the bolsters, while secure lashing points preventing joint motion during sea and road transport.


  • High pressure drilling risers
  • Marine drilling risers
  • Completion and workover risers (multiple joint lifts)
  • Stress joints
  • Special joints


  • Certified DNV 2.7-3 Portable Offshore Units, with type approved capacity up to 14t (DNV GL certificate no. S-8546).
  • Far smaller and easier to store than shipping baskets, minimise deckspace requirements and backloading.
  • Permits full access to the riser joint for inspection, maintenance, slinging and fastener installation.
  • Custom designs and higher load ratings available.

Handling tools

Evolved from Rocksteady’s proven high capacity collet locking mechanism; this ATEX handling tool can lift, fill and pressure test large diameter risers. It uses the same high capacity collet locking mechanism to lock into a machined groove in the bore of the riser.

This mechanism, coupled with SRP’s proprietary locking profile in the flange and optional bore seal, the tool offers maximum security with higher load and pressure testing capability.

The tool is designed and manufactured to API Spec 7K and API Spec 8C (ISO 13535) to 350t SWL (higher load ratings available). We have also supplied lifting and handling tools that interface with flange bolts, wellheads and API clamp hubs.


  • Drilling risers.
  • Stress and tension joints.
  • Drilling adaptor joints.
  • Subsea installation, including trees and wellheads.
  • Piles and conductors with handling grooves.


  • Balanced CoG and nose cone for easy horizontal and vertical installation
  • Clear visual indication and manual position lock
  • Fail safe hydraulic lock
  • Adaptable to a range of bore diameters and operations
  • Ideal for handling joints with wellhead profiles: separate lock on ID groove and protects seal areas
  • Optional riser fill, gasket retention and pressure testing capability