There are many older offshore steel pipelines that have been damaged or exhibit excessive corrosion whereby dropping below minimum wall thickness requirements. Conventional rehabilitation or replacement of existing offhshore flow back lines often times has been cost prohibitive for older lower producing wells resulting in the premature abandonment or closing of wells.
By pulling flexible reinforced thermoplastic pipes through the existing steel pipelines and multiple riser configurations, signifcant cost savings can be realized with minimal sea floor disturbance. The reduced capital costs allow wells to continue to be productive through their remaining lives without sacrificing pipeline integrity. This paper provides a detailed case study for a Petronas flow line in the Samarang Field describing the step by step processes required for a successful rehabilitation of a pipeline. This includes proper pipe sizing considerations to compensate for lower flow rates, material selection for the reinfoced thermoplastic pipe to withstand the pipleline flow environment, determination of pull force requirments, regulatory approvals, pre-installation preparation of the existing flow line, step by step installation procedures, testing and integrity requirements and how unforseen issues raised durning the process were addressed. The paper will conclude with lessons learned and what improvements were implemented for future projects as well as the cost benefits versus replaceing the steel lines