Page tree

Versions Compared

Key

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

Motivation

...


The Temperature Profile

...

The heat flow  in single-layer injector has three distinctive zones:

...

in Wellbore Production Homogeneous Flow Analytical @model  (see Fig. 1) is a combination of the basic analytical models:



See also

...

Petroleum Industry / Upstream / Subsurface E&P Disciplines / Dynamic Flow Model / Wellbore Flow Model (WFM) / Wellbore Production Homogeneous Flow @model

Heat flow equation for Semispace Linear Conduction:

LaTeX Math Block
anchor1
alignmentleft
\frac{\partial T}{\partial t} = a^2 \Delta T = a^2\frac{\partial^2 T}{\partial z^2}

Initial Conditions

LaTeX Math Block
anchor1
alignmentleft
T(t=0, z) = T_G(z)

Boundary conditions

LaTeX Math Block
anchor7685E
alignmentleft
T(t, z=0) = T_f = {\rm const}, \quad T(t, z \rightarrow \infty) = T_G(z)

The exact solution is given by following formula:

LaTeX Math Block
anchor1
alignmentleft
T(t,z) = T_f + (T_G(z) - T_f) \cdot \frac{2}{\sqrt{\pi}} \int_0^{z/\sqrt{4at}} e^{-\xi^2} d\xi

A fair approximation at late times (

LaTeX Math Inline
body\zeta \sim 0
) is given by expanding the integral:

LaTeX Math Block
anchorSLC
alignmentleft
T(t,z) = T_f + (T_G(z) - T_f) \cdot \Bigg[  1- \frac{\exp(-\zeta^2)}{\sqrt{\pi} \zeta} \bigg( 1- \frac{1}{2 \zeta}  + \frac{3}{4 \zeta^3} \bigg) \Bigg]

where

LaTeX Math Block
anchor1
alignmentleft
\zeta = \frac{z}{4 a t}

The final solution for temperature  above the flowing unit is represented by RHK pipe flow solution where TG is replaced with Tb from 

LaTeX Math Block Reference
anchorSLC
.

For the intervals between two injection units the one needs to account for the SLC contribution from upper flowing unit and from lower flowing unit which can be done using the superposition.

First, let's rewrite 

LaTeX Math Block Reference
anchorSLC
 in terms of temperature gain:

LaTeX Math Block
anchor66NAU
alignmentleft
dT(t, z) = T(t,z) - T_G(z)= -  (T_G(z) - T_f) \cdot    \frac{\exp(-\zeta^2)}{\sqrt{\pi} \zeta} \bigg( 1- \frac{1}{2 \zeta}  + \frac{3}{4 \zeta^3} \bigg) 

Now one can write down the temperature disturbance from the overlying flowing unit A1:

LaTeX Math Block
anchor66NAU
alignmentleft
dT_{b,over}(t, z) = T_{b,up}(t,z) - T_G(z)= -  (T_G(z) - T_{f, A1}) \cdot    \frac{\exp(-\zeta^2)}{\sqrt{\pi} \zeta} \bigg( 1- \frac{1}{2 \zeta}  + \frac{3}{4 \zeta^3} \bigg) 
and from the underlying flowing unit A2:
LaTeX Math Block
anchor66NAU
alignmentleft
dT_{b,under}(t, z) = T_{b,up}(t,z) - T_G(z)= -  (T_G(z) - T_{f, A2}) \cdot    \frac{\exp(-\zeta^2)}{\sqrt{\pi} \zeta} \bigg( 1- \frac{1}{2 \zeta}  + \frac{3}{4 \zeta^3} \bigg) 

The background temperature disturbance between the flowing units will be:

LaTeX Math Block
anchor66NAU
alignmentleft
T_b(t, z) = T_G(z) + dT_{b,over}(t, z) + dT_{b,under}(t, z)

Replacing the static value of 

LaTeX Math Inline
bodyT_G(z)
 in RHK model with dynamic value of  
LaTeX Math Inline
bodyT_b(t, z)
 one arrives to the final wellbore temperature model with account of heat exchange with surrounding rocks and cooling effects from flowing units (Semispace Linear Conduction).

See also

Physics / Fluid Dynamics / Linear Fluid Flow 

Subsurface Temperature Profile around Lateral Flow Analytical @model ]

References

...

grouparax

Semiplane Temperature Model.pptx

С. В. Новиков, ТЕПЛОВЫЕ СВОЙСТВА ТЕРРИГЕННЫХ КОЛЛЕКТОРОВ И НАСЫЩАЮЩИХ ФЛЮИДОВ, 2009.pdf

...

 [ Temperature Profile in Homogenous Stationary Pipe Flow Analytical Ramey @model ]