Difference between revisions of "DFIT"

From wiki.pengtools.com
Jump to: navigation, search
(Created page with "==Brief== thumb|right|300px| Stimulated well drainage DFIT Diagnostic Fracture Injection Test. ==Math & Physics== Steady state flow bo...")
 
(→‎Brief)
Line 2: Line 2:
 
[[File:fracture linear flow.png|thumb|right|300px| Stimulated well drainage]]
 
[[File:fracture linear flow.png|thumb|right|300px| Stimulated well drainage]]
  
−
[[DFIT]] Diagnostic Fracture Injection Test.
+
[[DFIT]] Diagnostic Fracture Injection Test or the fracture calibration injection falloff test offers a way to estimate fluid efficiency, leak off coefficient, formation permeability and pressure before the main hydraulic fracture treatment.
  
 
==Math & Physics==
 
==Math & Physics==

Revision as of 13:43, 16 February 2022

Brief

Stimulated well drainage

DFIT Diagnostic Fracture Injection Test or the fracture calibration injection falloff test offers a way to estimate fluid efficiency, leak off coefficient, formation permeability and pressure before the main hydraulic fracture treatment.

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

6/π stimulated well potential
JD
optiFrac
fracDesign
Production Potential

Nomenclature

A = cross-sectional area, cm2
h = thickness, m
J_D = dimensionless productivity index, dimensionless
k = permeability, d
P = pressure, atm
P_i = initial pressure, atm
\bar P = average pressure, atm
q = flow rate, cm3/sec
x = length, m
x_e = drinage area length, m
y_e = drinage area width, m

Greek symbols

\mu =viscosity, cp
Retrieved from "https://wiki.pengtools.com/index.php?title=DFIT&oldid=7260"