Page 27 - Handbook Of Multiphase Flow Assurance

Flow assurance requirements 21

oped for petroleum multiphase flow as Beggs and Brill, etc. Vertical flow correlations were
developed and updated by Coleman, Turner, which allowed to estimate the gas flow rate at
which liquids accumulate at well bottom in a production tubing pipe if gas velocity is insuf-
ficient to lift the liquids from a well.
Production and process engineers realized that individual aspects of multiphase flow as-
surance worked together as flow through pipes submerged in cold subsea water and gas
expansion in wells and riser caused cooling of fluids which led to the formation of wax, hy-
drates, and sulfate scale.
The term “Flow Assurance” is a literal translation of Portuguese phrase “Garantia de
Escoamento.” The term "flow assurance" was coined in 1994, at the Deepstar-PROCAP
Technology Exchange Workshop held at Petrobras and focused mainly on paraffins and hy-
drates, by the lady from Colombia by the name Magali Cotrim, who was the technology pro-
gram manager for Petrobras (Minami, 2017). The term translated easily and meaningfully into
English and took root. Since then, the petroleum industry saw a lot of change. Several com-
panies recently started to use internally a new term Production Assurance. The term “Flow
assurance” also exists around the globe. In Hindi, this would translate as “Pravaah Sunishchit
Karya” प्रवाह सुनिश्चित करना (flow assurance work), in Russian, it would be “Obespechenie
Potoka” Обеспечение Потока (assurance of flow), and in Mandarin it would be “Liu Dong
Bao Zhang” 流动保障 (flow security). Prior to the English translation, the term "Garantia de
Escoamento" existed as part of the Petrobras PROCAP 1000 program in Brazil (Neto, 2006).
The PROCAP program which stands for Programa de Capacitação Tecnológica em Sistemas
de Produção para Águas Profundas also promoted the standardization of subsea trees.

Flow assurance requirements

With that brief introduction we can discuss what the flow assurance comprises and what
information is necessary to perform a reliable analysis of a petroleum system to assure unin-
terrupted oil and gas production.

Basis of design
A document listing all parameters necessary to allow planning of an approach to solving
flow assurance challenges usually is known as a basis of design.
Key knowledge requirements for flow assurance analysis of a system include:
1. depth profile of a wellbore and an onshore flow line elevation profile or bathymetry of a
subsea flow line, a riser and an export pipeline
2. expected flow rate of produced fluids
3. environment properties
4. fluid characterization
These four basic categories include multiple sub-elements. Basis of design should have as
detailed information as possible about bathymetry, fluids, production profile and environ-
ment properties. Often exact information is not readily available or is too costly to obtain.
In such cases, field analogs from the region may provide approximate indication of typical