الفهرس 
قرار لجنة المناقشة والحكمOnly 14 pages are availabe for public view
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Abstract
In the oil field, the system is designed so that the flow velocity does not reach the
erosional velocity value to achieve safe operation for the piping systems to avoid the
pipeline damage. When the flow velocity inside the pipeline is equal to or higher than
its erosional velocity, a large erosion rate of the pipe surface has occurred. Then, the
lifetime of the piping system decreases. The erosional velocity is defined as the
velocity value when erosion starts to occur in the piping system. The erosional
velocity has great importance in the oil field. Once the flow velocity reaches it, there
will be a restriction for further increase for pipeline transportation capacity.
The increase of oil production by the available capabilities is always very required
because it contributes to the country’s economy. Many researchers and associations
pay great efforts in this research side. One of the first associations which started in
this field is the American Petroleum Institute (API) where The American Petroleum
Institute Recommended Practice 14E (API RP- 14E) studied the erosional velocity
limits at the oil pipeline systems. It puts an empirical equation to estimate the
erosional velocity for no solid flow (not actual flow). The API RP 14E equation states
that the erosional velocity value depends only on both the mixture density and an
empirical constant. There is no frank clarification for its constant criteria. Recently,
the erosional velocity became an important item in the flow assurance science which
it improves the oil production systems exploiting all available system components.
So, in the present study, an alternative calculation methodology is used to estimate
the recommended erosional velocity value for multiphase flow (actual flow) for
several oilfield pipeline materials. This methodology is based on an analytical study
of erosion due to liquid droplet impingement, solid particle impingement, and friction.
The derived equations are verified with the help of the experimental results published
in some previous researches. Ensuring the equations validation, these equations are
used in this study. Also, the methodology clarifies the different erosion factors and
indicates the most effective one where these parameters have different effects on the
erosional velocity value. Some are very effective parameters that determine the
minimum limit value of the erosional velocity. Other parameters have a small effect
on the erosional velocity. Other parameters give noticeable changes for the erosional
velocity but these parameters do not determine the minimum limit for it.
The new recommended higher values of the erosional velocity compared to those of
API RP- 14E represent addition in oilfield piping production systems. In the discussed
case study, the erosional velocity based on API RP- 14E is 4.59 m/s, whereas the final
recommended erosional velocity by this thesis is evaluated as 10 m/s. The present
research gives an economic analysis for the case of the oil transportation pipeline to
spotlight the erosional velocity limit importance for the country’s economy. So, In the
economic study, Doubling the erosional velocity in the considered case study results
in an achievement of a double economical benefit.