Difference between revisions of "JD"

Revision as of 11:12, 28 March 2019

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}}

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

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

The maximum possible stimulated well potential for pseudo steady linear flow is:

${J_D}_{max}= \frac{6}{\pi} \approx 1.91$ , see 6/π stimulated well potential

The maximum possible stimulated well potential for steady state linear flow is:

${J_D}_{max}= \frac{4}{\pi} \approx 1.27$ , see 4/π stimulated well potential

B

= formation volume factor, bbl/stb

J_D

= dimensionless productivity index, dimensionless

kh

= permeability times thickness, md*ft

\bar{P}

= average reservoir pressure, psia

P_{\bar{P}}

= average reservoir pseudopressure, psia²/cP

P_{wf}

= well flowing pressure, psia

P_{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 9: / Line 9: @@
 :<math> {J_D} = \frac{1}{ln{\frac{r_e}{r_w}-\frac{3}{4}+S}} </math>
-Oil
+===Oil===
 :<math> {J_D} = \frac{141.2 B \mu}{kh} \frac{q}{\bar{P} - P_{wf}} </math>
-Gas
+===Gas===
 :<math>J_D=\frac{1422 \times 10^3\ T_R}{kh} \frac{q_g}{P_{\bar{P}}-P_{P_{wf}}}</math>