Difference between revisions of "JD"

Revision as of 16:44, 11 August 2018

JD - dimensionless productivity index, inverse of dimensionless pressure (based on average pressure) ^[1].

From the Darcy's law for an unfractured well located in the center of a circular drainage area, the JD in pseudo-steady state is as follows:

{J_D} = \frac{1}{ln{\frac{r_e}{r_w}-\frac{3}{4}+S}}

Oil

{J_D} = \frac{141.2 B \mu}{kh} \frac{q}{\bar{P} - P_{wf}}

Gas

J_D=\frac{1422 \times 10^3\ T_R}{kh} \frac{q_g}{P_{\bar{P}}-P_{P_{wf}}}

B

= formation volume factor, bbl/stb

J_D

= dimensionless productivity index, dimensionless

kh

= permeability times thickness, md*ft

\bar{P}

= average reservoir pressure, psia

Failed to parse (syntax error): P_{\bar{P} = average reservoir pseudopressure, psia²/cP

P_{wf}

= well flowing pressure, psia

Failed to parse (syntax error): P_{wf}} = average well flowing pseudopressure, psia²/cP

q

= flowing rate, stb/d

q_g

= gas rate, MMscfd

r_w

= wellbore radius, ft

r_e

= drainage radius, ft

S

= skin factor, dimensionless

T

= temperature, °R

\mu

= viscosity, cp

↑ Rueda, J.I.; Mach, J.; Wolcott, D. (2004). "Pushing Fracturing Limits to Maximize Producibility in Turbidite Formations in Russia" (SPE-91760-MS). Society of Petroleum Engineers.

@@ Line 20: / Line 20: @@
 :<math> kh</math> = permeability times thickness, md*ft
 :<math> \bar{P} </math> = average reservoir pressure, psia
+:<math> P_{\bar{P} </math> = average reservoir pseudopressure, psia<sup>2</sup>/cP
 :<math> P_{wf} </math> = well flowing pressure, psia
+:<math> P_{wf}} </math> = average well flowing pseudopressure, psia<sup>2</sup>/cP
 :<math> q </math> = flowing rate, stb/d
 :<math> q_g </math> = gas rate, MMscfd
@@ Line 26: / Line 28: @@
 :<math> r_e </math> = drainage radius, ft
 :<math> S </math> = skin factor, dimensionless
+:<math> T </math> = temperature, °R
 ===Greek symbols===