The document discusses the internal lining of carbon steel flowlines with a fluorinated polymer liner. It argues that this lining solution can reduce capital expenditures (CAPEX) and operational expenditures (OPEX) compared to traditional corrosion-resistant alloy (CRA)-based solutions. It provides analysis showing potential CAPEX savings from material costs and reduced project complexity, as well as OPEX savings from reduced wax deposition and drag. Real-world test results and an offshore track record with a similar lining technology are also cited. The lining solution could improve project management and flow assurance while lowering costs.

1. Internal lining of carbon steel flowlines with a plastic liner based on a
fluorinated polymer. Introduction of the concept and evidences on CAPEX
and OPEX reductions.
Nicasio Messina
Solvay Specialty Polymers Italy S.p.A., nicasio.messina@solvay.com
Keyword(s): PVDF, lining, flexible, flow assurance, deposition, capex, opex.
Abstract:
Capex reduction and project management complexity are at the top of the list of the
main drivers for subsea flowlines, together with the water depth and the opex
increases. Rigid risers and flowlines remain the main solutions used for offshore field
but the new market conditions are forcing the industry to increase the attention towards
more cost-competitive solutions over the current CRA-based ones.
This paper describes the main performances and characteristics of fluorinated
polymers, already used in offshore flexible risers, as potential use for internal lining of
rigid flowlines.
The scope of the paper is: i) to provide the evidence on the positive impact on CAPEX
and project management complexity brought by the lining solution, ii) to provide data
on the flow assurance advantages and iii) to provide an insight on the positive impact
on the OPEX reduction and on the operational complexity improvements.
The paper is composed of three sessions. A first session will provide a mechanical
analysis of the performance of the polymer in respect of the main technical
requirements of the lining solution. Going through the existing track record in offshore,
the main chemical and permeation resistance characteristics of the polymer are shown.
The second session focuses on a cost analysis. A first Capex analysis, mainly both
based on material cost comparison, shows the advantage of using this lining solution
over the CRA based ones. Then, starting from an overview of the main surface
properties of the polymer proposed, this paper will also show wax-deposition test data
and a DRAG reduction simulation analysis. The DRAG analysis was initiated from real
service conditions, considering different types of service for the flowlines, and was

2. done in comparison with existing metallic solutions. This analysis then, provides an
idea of the OPEX reduction and operational advantages of the use of plastic lined
pipelines vs metallic solutions.
The third session completes the paper with some results from real in-field tests, which
were performed onshore, and also with a real track-record on a new lining technology,
used offshore and based on the polymer here proposed.
Conclusions show CAPEX and OPEX advantages, the improvement in the project
management, with the possibility to increase the level of the local content (where
requested) of the project and then also the flow assurance advantages and the OPEX
reduction associated to the lining solution.