Case Study 2865 – John Shaw BOP

John Shaw – BOP Frame

Rig Name: John Shaw
Rig Type: semi-submersible
Owner name: Transocean Ltd.
Classification Society: DNV
Pertinent code: ASD (WSD method)

Model 3D
Please download PDF version to see 3D model – click here

Project description
Rig Engineering (RE) was tasked by Transocean Inc. (TOI) to perform structural verification of the BOP frames to assess the adequacy of the frames to support the entire stacked up weight via 4 off elephant feet instead of centrally on the test stump via wellhead connector. This assessment includes various load cases as well as splitting BOP package which in turn disrupt the load path and load sharing between the upper and lower fames. Where applicable, engineer the strengthening members to allow this operation to take place.

FEA Model and pictures of Existing BOP Frame

R.E. Scope of work
Rig Engineering constructs FEA model of the frame from 2D CAD drawings and prepare the model for submitting successive loadings and load case combinations as follows:

• Verification against normal operating condition.

• Verification against damaged stability and ocean tow condition.

• Unequal load sharing between the annular and wellhead buckets.

• Report on reactions to deck to allow TOI to check adequacy of hull scantlings in way of elephant feet.
Engagement Condition
Upload your problem to us and give us relevant input to allow us to resolve your problem, we will need:
1. As-built drawings to create 3D model for FEA purpose (of BOP frame)
2. Weight and centre of gravity of BOP components.
Key word: Rig Engineering, John Shaw, semi-submersible, BOP Modification, Wellhead Spider, Spider Frame, Wellhead Connector, Wellhead Bucket, BOP frame strength verification.