Difference between revisions of "4/π stimulated well potential"

From wiki.pengtools.com
Jump to: navigation, search
(Nomenclature)
(Math & Physics)
Line 14: Line 14:
 
From [[Darcy's law]]:
 
From [[Darcy's law]]:
  
:<math>\frac{q}{2}=\frac{kA}{B \mu}\ \frac{dP}{dx}</math>
+
:<math>\frac{q}{2}=\frac{kA}{\mu}\ \frac{dP}{dx}</math>
  
 
:<math> A =y_e*h</math>
 
:<math> A =y_e*h</math>
  
:<math>dP=\frac{q B \mu}{2ky_eh} dx</math>
+
:<math>dP=\frac{q \mu}{2ky_eh} dx</math>
  
Integration gives: <math>P-P_{wf}=\frac{q B \mu}{2ky_eh} x</math>
+
Integration gives: <math>P-P_{wf}=\frac{q \mu}{2ky_eh} x</math>
  
 
Since average pressure is: <math>\bar P = \frac{\int P dx}{\int dx}</math>
 
Since average pressure is: <math>\bar P = \frac{\int P dx}{\int dx}</math>
  
:<math> \bar P = \frac{ \int \limits_{0}^{x_e/2} \left ( \frac{q B \mu}{2ky_eh} x + P_{wf} \right ) dx}{\int dx} = \left. \frac{q B \mu}{2ky_eh} \frac{x}{2} \right|_{x=0}^{x=x_e/2} + P_{wf} = \frac{q B \mu x_e}{8ky_eh} + P_{wf}</math>
+
:<math> \bar P = \frac{ \int \limits_{0}^{x_e/2} \left ( \frac{q \mu}{2ky_eh} x + P_{wf} \right ) dx}{\int dx} = \left. \frac{q \mu}{2ky_eh} \frac{x}{2} \right|_{x=0}^{x=x_e/2} + P_{wf} = \frac{q \mu x_e}{8ky_eh} + P_{wf}</math>
  
:<math>J_D=\frac{q B \mu}{2 \pi k h} \frac{1}{( \bar P - P_{wf})} =\frac{q B \mu}{2 \pi k h} \frac{8ky_eh}{q B \mu x_e} = \frac{4y_e}{\pi x_e}=\frac{4}{\pi}</math>
+
:<math>J_D=\frac{q \mu}{2 \pi k h} \frac{1}{( \bar P - P_{wf})} =\frac{q \mu}{2 \pi k h} \frac{8ky_eh}{q \mu x_e} = \frac{4y_e}{\pi x_e}=\frac{4}{\pi}</math>
  
 
==See also==
 
==See also==

Revision as of 11:28, 10 September 2018

Brief

Stimulated well drainage

4/π is the maximum possible stimulation potential for steady state linear flow in a square well spacing.

Math & Physics

Steady state flow boundary conditions:

P |_{x=x_e/2} = P |_{x=-x_e/2} = P_i
 \frac{dP}{dt} =0\ for \ \forall x

From Darcy's law:

\frac{q}{2}=\frac{kA}{\mu}\ \frac{dP}{dx}
 A =y_e*h
dP=\frac{q \mu}{2ky_eh} dx

Integration gives: P-P_{wf}=\frac{q \mu}{2ky_eh} x

Since average pressure is: \bar P = \frac{\int P dx}{\int dx}

 \bar P = \frac{ \int \limits_{0}^{x_e/2} \left ( \frac{q \mu}{2ky_eh} x + P_{wf} \right ) dx}{\int dx} = \left. \frac{q \mu}{2ky_eh} \frac{x}{2} \right|_{x=0}^{x=x_e/2} + P_{wf} = \frac{q \mu x_e}{8ky_eh} + P_{wf}
J_D=\frac{q \mu}{2 \pi k h} \frac{1}{( \bar P - P_{wf})} =\frac{q \mu}{2 \pi k h} \frac{8ky_eh}{q \mu x_e} = \frac{4y_e}{\pi x_e}=\frac{4}{\pi}

See also

optiFrac
fracDesign
Production Potential

Nomenclature

 A = cross-sectional area, cm2
 h = thickness
 k = permeability
 x = length
 x_e = drinage area length
 y_e = drinage area width
 P = pressure
 P_i = initial pressure
 \bar P = average pressure
 q = flow rate

Greek symbols

 \mu = oil viscosity