Page 207 - Handbook Of Multiphase Flow Assurance

CHAPTER
7

Flow assurance deliverability issues

OUTLINE

Flowline design process 205 Cold flow and emulsion 207
Heavy oil viscosity 208
Optimization of flowline sizes 206
Emulsion rheology 208
Artificial lifting 206
References 209
Topsides equipment and arrival Further reading 209
pressures 207

Flowline design process

Flowline design is in the realm of pipeline engineers, but is done in collaboration with
flow assurance specialists. The flow assurance analysis helps indicate whether the pipe is
sufficiently large or too large for the life of the project and whether flow is likely to be stable
or intermittent. Flow assurance also helps forecast the amount of liquids arriving into the
process equipment at various stages of the project life.
Pipeline sizing considerations are usually based on two boundary conditions: pressure
and velocity.
Pressure in a pipeline should not to exceed the pipe design pressure.
Usually the MAOP is set with a safety margin of between few bar and up to 10% lower
than the design pressure, to allow for pressure surges during transient flow events such as
production startup or shutdown.
Velocity in a pipeline should not exceed the erosional velocity. Maximum velocity is deter-
mined based on operator internal design considerations for erosion, fluid corrosivity, or on
recommended guidelines provided by API, DNV or NORSOK. Regional regulatory require-
ments may prescribe which method to use for the flow velocity considerations.
In some cases, velocity should not drop below a certain minimum threshold to ensure
produced solids such as sand are transported by the flow. Typical minimum liquid velocity

Handbook of Multiphase Flow Assurance 205 © 2019 Elsevier Inc. All rights reserved.
https://doi.org/10.1016/B978-0-12-813062-9.00007-5