Mudline Suspension System

NuStar Mudline Suspension System (NSMS) offers a complete solution for the suspension of casing at or below the mudline level, to provide pressure control and annulus access to the surface wellhead. It provides operators the flexibility of abandoning a well and tying back to surface at a later date, due to weather, rig and other factors. Designed in accordance to API 17D Specification requirements, the NSMS features a stack-down configuration, with high load and pressure capacities and metal-to-metal seal integrity. Standard casing configuration is 30” x 20” x 13 3/8” x 9 5/8” (with 7” option) with 10,000 psi pressure rating, while equipment for alternate casing configurations are available upon request.


The NS-T Threaded Connector has the following features:

  • Separate left-hand running threads and righthand tieback threads of hangers for speed and ease of installation and protect sealing profile
  • High internal pressure rating for individual casing hangers
  • Design pressure rating of 10,000 psi for 9 5/8” casing hanger
  • High load capacity rating for individual casing hangers
  • Large flow-by areas.
  • Metal-to-metal seals with elastomeric back-up for high sealing integrity
  • Unique split lock ring design with enhanced flow-by area for circulation and double load teeth for high load transfer capabilities
  • Ease of installation and retrieval of temporary abandonment caps with J profile