The contract's scope includes 43 joints for drilling from a tension leg platform in a water depth of 780m, 75km off the coast of Pointe Noire.
Manufacturing and assembly work will take place in the UK and mainland Europe.
The equipment is due to be delivered by March 2015.
SRP managing director Jonny Shield said the contract provided a solid base from which SRP could grow and provide its riser engineering and procurement capability offering to other companies.