Page tree

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Fluid flow with fluid pressure 

LaTeX Math Inline
bodyp(t, {\bf r})
 is linearly changing  linearly changing in time:

LaTeX Math Block
alignmentleft
p(t, {\bf r}) = \psi({\bf r}) + A \cdot t, \quad A = \rm const


The fluid temperature  

LaTeX Math Inline
bodyT(t, {\bf r})
 is supposed to vary slowly enough to provide quasistatic equilibrium.


The fluid velocity 

LaTeX Math Inline
body{\bf u}(t, {\bf r})
 may not be stationary.

In the most general case (both reservoir and pipelines) the fluid velocity is proportional to pressure gradient and can be written asmotion equation is of fluid pressure and pressure gradient:

LaTeX Math Block
anchoru
alignmentleft
{\bf u}(t, {\bf r})= - MF({\bf r}, p, \nabla p) \nabla p

with right side dependent on time through the pressure variation.


In case of linear correlation: the flow with velocity dependent on pressure  gradient only

LaTeX Math Inline
bodyM({\bf r}, p, \nabla p) = Mu} = {\bf u}({\bf r}, \nabla p)
) the PSS flow velocity will be stationary as the right side of
LaTeX Math Block Reference
anchoru
 is not dependant on time.The fluid temperature  
LaTeX Math Inline
bodyT(t, {\bf r})
 is supposed to vary slowly enough to provide quasistatic equilibrium.


In terms of Well Flow Performance the PSS flow means:

...

Fig. 1. PTA Diagnostic Plot for vertical well in single-layer homogeneous reservoir with impermeable circle boundary (PSS).

Pressure is in blue and log-derivative is in red.


See Also

...

Petroleum Industry / Upstream /  Production / Subsurface Production / Field Study & Modelling / Production Analysis / PSS Diagnostics

Steady State (SS) well fluid flow regime ]