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We start with reservoir pressure diffusion outside wellbore:

LaTeX Math Block
anchorrho_dif
alignmentleft
\frac{\partial (\rho \phi)}{\partial t} + \nabla \, ( \rho \, {\bf u}) = \sum_k \dot m_k(t) \cdot \delta({\bf r}-{\bf r}_k)
LaTeX Math Block
anchorqGamma
alignmentleft
{\rm F}_{\Gamma}(p, {\bf u}) = 0

where

LaTeX Math Inline
body\Sigma_k

well-reservoir contact of the 

LaTeX Math Inline
bodyk
-th well

LaTeX Math Inline
body--uriencoded--d %7B\bf \Sigma%7D

normal vector of differential area on the well-reservoir contact, pointing inside wellbore

LaTeX Math Inline
body \dot m_k(t)

mass flowrate at 

LaTeX Math Inline
bodyk
-th well 
LaTeX Math Inline
body \dot m_k(t) = \rho(p) \cdot q_k(t)

LaTeX Math Inline
bodyq_k(t)

sandface flowrate at 

LaTeX Math Inline
bodyk
-th well 

LaTeX Math Inline
body\rho(p)

fluid density as function of reservoir fluid pressure 

LaTeX Math Inline
bodyp

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LaTeX Math Block
anchorrhophi
alignmentleft
d(\rho \, \phi) = \rho \, d \phi + \phi \, d\rho = \rho \, \phi \, \left( \frac{d \phi }{\phi} +  \frac{d \rho }{\rho}  \right) 
= \rho \, \phi \, \left( \frac{1}{\phi} \frac{d \phi}{dp} \, dp +  \frac{1}{\rho} \frac{d \rho}{dp} \, dp  \right) 
= \rho \, \phi \, (c_{\phi} \, dp + c \, dp) = \rho \, \phi \, c_t \, dp

where

LaTeX Math Inline
bodyc_t = с_\phi+ c

to arrive at:

LaTeX Math Block
anchorpre_filnal
alignmentleft
\rho \, \phi \, c_t  \cdot \frac{\partial p}{\partial t} + \nabla \, ( \rho \, {\bf u}) = \rho \, \sum_k q_k(t) \cdot \delta({\bf r}-{\bf r}_k)
LaTeX Math Block
anchorqGamma
alignmentleft
{\rm F}_{\Gamma}(p, {\bf u}) = 0

Then use the following equality:

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Substituting

LaTeX Math Block Reference
anchornabla_rho
 into
LaTeX Math Block Reference
anchorpre_filnal
 and reducing the density 
LaTeX Math Inline
body\rho(p)
 one arrives to:

LaTeX Math Block
anchorpre_filnal
alignmentleft
 \phi \, c_t  \cdot \frac{\partial p}{\partial t} + \nabla  {\bf u}  
+ c \cdot ( {\bf u} \, \nabla p) =  \sum_k q_k(t) \cdot \delta({\bf r}-{\bf r}_k)
LaTeX Math Block
anchorqGamma
alignmentleft
{\rm F}_{\Gamma}(p, {\bf u}) = 0


See also

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Physics / Mechanics / Continuum mechanics / Fluid Mechanics / Fluid Dynamics / Pressure Diffusion / Pressure Diffusion @model / Single-phase pressure diffusion @model

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