Difference between revisions of "Gas Flowing Material Balance"

Latest revision as of 18:00, 3 November 2018

Brief

Gas Flowing Material Balance (Gas FMB) is the advanced engineering technique published in 1998 by Louis Mattar ^[1].

Gas Flowing Material Balance is applied to determine:

Reservoirs GIIP calculation
Reservoirs EUR calculation
Well's EUR and JD

Gas Flowing Material Balance uses readily available Well flowing data: production rate and tubing head pressure.

The interpretation technique is fitting the data points with the straight lines to calculate GIIP and JD.

Gas Flowing Material Balance in the E&P Portal

Math & Physics

Combining the gas pseudo state flow equation and the Gas Material Balance equation to get Gas Flowing Material Balance equation:

P_{\bar{P}}= P_{P_{wf}} + q_g b_{pss}

^[2]

where

b_{pss} = \frac{1422 \times 10^3\ T_R}{kh\ J_D}

Material balance pseudo-time:

t_{ca} = \frac{\mu_{gi} c_{gi}}{q_g}\int\limits_{0}^{t}\frac{q_g}{\bar{\mu_g} \bar{c_g}}dt

Discussion

Gas Flowing Material Balance can be applied to:

single well
multiple wells producing from the same Reservoir.

The X axis on the Gas Flowing Material Balance Plot can be selected as:

Well cumulative
Reservoir cumulative

Example 1. Multiple wells producing from the same Reservoir. X axis - Wells cumulative Example 2. Multiple wells producing from the same Reservoir. X axis - Reservoir cumulative Example 3. Shifted Model Start (to account for gas injection)

Workflow

Upload the data required
Open the Gas Flowing Material Balance tool here
Calculate the red line:
1. Given the GIIP
2. Calculate the $\frac{P}{z}=\frac{P_i}{z_i} \left (1- \frac{G_p}{GIIP}\right )$
Calculate the orange curve:
1. Given the flowing wellhead pressures, calculate the flowing bottomhole pressures, $P_{wf}$
2. Convert the flowing pressures to pseudopressures, $P_{P_{wf}}$
3. Given the JD, calculate the $b_{pss}$
4. Calculate the pseudopressure, $P_{\bar{P}}$
5. Convert the pseudopressure to pressure, $\bar{P}$
6. Calculate the $\frac{\bar{P}}{z}$
Calculate the gray JD curve:
1. Calculate the gas productivity index, $J=\frac{q_g}{P_{\bar{P}}-P_{P_{wf}}}$
2. Calculate the JD, $J_D=\frac{1422 \times 10^3\ T_R}{kh} J$
Change the red line to match the orange curve
1. Change the GIIP
2. Change the intitial $\frac{P}{z}$
Change the flat JD gray line to match the changing JD gray line
Save the FMB model
Move to the next well

Extra Plot to find b_pss

Calculate the initial pseudopressure, $P_{Pi}$
Calculate the material balance pseudo-time, $t_{ca}$
Plot $\frac{P_{P_i}-P_{P_{wf}}}{q_g}$ versus $t_{ca}$
The intercept with the Y axis gives $b_{pss}$ and $J_D$

Data required

Create Field here
Create or Upload Reservoirs here
Input the Reservoirs GIIP and STOIIP here
Create or Upload PVT (SG, Pi, Ti) here
Upload Wells
Create or Upload Wells Perforations here
Create or Upload kh and JD here
Upload Daily Measures

In case you need to calculate the flowing bottomhole pressure from the wellhead pressure:

Calculate the flowing bottomhole pressures using BHP Calculator
Export flowing bottomhole pressures to Daily Measures here

In case you want to add the static reservoir pressures on the FMB Plot:

Create or Upload the static reservoir pressures, here
Calculate Monthly Measures from the Daily Measures using Monthly Data Calculator

Nomenclature

b_{pss}

= reservoir constant, inverse to productivity index, psia²/cP/MMscfd

c

= compressibility, psia^-1

GIIP

= gas initially in place, MMscf

G_p

= cumulative gas produced, MMscf

J

= gas productivity index, MMscfd/(psia²/cP)

J_D

= dimensionless productivity index, dimensionless

kh

= permeability times thickness, md*ft

P

= pressure, psia

\bar{P}

= average reservoir pressure, psia

P_P

= pseudopressure, psia²/cP

q_g

= gas rate, MMscfd

t

= time, day

t_{ca}

= material balance pseudotime for gas, day

T

= temperature, °R

z

= gas compressibility factor, dimensionless

Greek symbols

\mu

= viscosity, cp

Subscripts

g = gas

i = initial

R = °R

wf = well flowing

References

↑ Mattar, L.; McNeil, R. (1998). "The "Flowing" Gas Material Balance" (PDF). Journal of Canadian Petroleum Technology. Petroleum Society of Canada.
↑ Mattar, L.; Anderson, D (2005). "Dynamic Material Balance (Oil or Gas-In-Place Without Shut-Ins)" (PDF). CIPC.

[Mattar1998-1] Mattar, L.; McNeil, R. (1998). "The "Flowing" Gas Material Balance" (PDF). Journal of Canadian Petroleum Technology. Petroleum Society of Canada.

[Mattar2005-2] Mattar, L.; Anderson, D (2005). "Dynamic Material Balance (Oil or Gas-In-Place Without Shut-Ins)" (PDF). CIPC.

[1]

[2]

@@ Line 2: / Line 2: @@
 == Brief ==
-[[Gas Flowing Material Balance]] is the advanced engineering technique to determine the [[Reservoirs]] GIIP and recovery as well as [[Well]]'s [[EUR]] and [[JD]].
+[[Gas Flowing Material Balance]] '''(Gas FMB)''' is the advanced engineering technique published in '''1998''' by Louis Mattar <ref name=Mattar1998/>.
-[[Gas Flowing Material Balance]] is applied on the [[Well]] level given readily available well flowing data: production rate and tubing head pressure.
+[[Gas Flowing Material Balance]] is applied to determine:
+* [[Reservoirs]] GIIP calculation
+* [[Reservoirs]] [[EUR]] calculation
+* [[Well]]'s [[EUR]] and [[JD]]
-The interpretation technique is fitting the data points with the straight line to estimate GIIP and [[JD]].
+[[Gas Flowing Material Balance]] uses readily available [[Well]] flowing data: production rate and tubing head pressure.
+The interpretation technique is fitting the data points with the straight lines to calculate GIIP and [[JD]].
+[[File:FMB.png|link=https://ep.pengtools.com/matbal/flowing-material-balance/gas]]
+<center>[[Gas Flowing Material Balance]] in the [https://ep.pengtools.com/matbal/flowing-material-balance/gas E&P Portal]</center>
 == Math & Physics ==
-Combine the gas pseudo state flow equation and the [[Gas Material Balance]] equation to get [[Gas Flowing Material Balance]] equation:
+Combining the gas pseudo state flow equation and the [[Gas Material Balance]] equation to get [[Gas Flowing Material Balance]] equation:
 :<math> P_{\bar{P}}= P_{P_{wf}} + q_g b_{pss}</math> <ref name=Mattar2005/>
@@ Line 23: / Line 32: @@
 ==Discussion==
+[[Gas Flowing Material Balance]] can be applied to:
+*single well
+*multiple wells producing from the same [[Reservoirs| Reservoir]].
+The X axis on the [[Gas Flowing Material Balance]] Plot can be selected as:
+*[[Well]] cumulative
+*[[Reservoirs| Reservoir]] cumulative
+'''Example 1. Multiple wells producing from the same Reservoir. X axis - Wells cumulative'''
+[[File:FMBex1.png|link=https://ep.pengtools.com/matbal/flowing-material-balance/gas]]
+'''Example 2. Multiple wells producing from the same Reservoir. X axis - Reservoir cumulative'''
+[[File:FMBex2.png|link=https://ep.pengtools.com/matbal/flowing-material-balance/gas]]
+'''Example 3. Shifted Model Start (to account for gas injection)'''
+[[File:FMBex3.png|link=https://ep.pengtools.com/matbal/flowing-material-balance/gas]]
 ==Workflow==
-# Convert initial pressure to pseudopressure, <math>P_{Pi}</math>
+# Upload the data required
-# Convert flowing tubing pressure to flowing bottomhole pressure, <math>P_{wf}</math>
+# Open the [[Gas Flowing Material Balance]]  tool [https://ep.pengtools.com/matbal/flowing-material-balance/gas here]
-# Convert all flowing pressures to pseudopressures, <math>P_{P_{wf}}</math>
+# Calculate the red  <math> \frac{P}{z}</math> line:
-# Calculate material balance pseudo-time, <math>t_{ca}</math>
+## Given the GIIP
-# Plot <math>\frac{P_{P_i}-P_{P_{wf}}}{q}</math> versus <math>t_{ca}</math>. The intercept gives  <math>b_{pss}</math> and <math>J_D</math>.
+## Calculate the <math> \frac{P}{z}=\frac{P_i}{z_i} \left (1- \frac{G_p}{GIIP}\right )</math>
-# Calculate the average reservoir pseudopressure from [[Gas Flowing Material Balance]] equation, <math>P_{\bar{P}}</math>
+# Calculate the orange <math> \frac{\bar{P}}{z}</math> curve:
+## Given the flowing wellhead pressures, calculate the flowing bottomhole pressures, <math>P_{wf}</math>
+## Convert the flowing pressures to pseudopressures, <math>P_{P_{wf}}</math>
+## Given the [[JD]], calculate the <math> b_{pss}</math>
+## Calculate the pseudopressure, <math> P_{\bar{P}}</math>
+## Convert the pseudopressure to pressure, <math> \bar{P}</math>
+## Calculate the <math> \frac{\bar{P}}{z}</math>
+# Calculate the gray [[JD]] curve:
+## Calculate the gas productivity index, <math>J=\frac{q_g}{P_{\bar{P}}-P_{P_{wf}}}</math>
+## Calculate the [[JD]], <math>J_D=\frac{1422 \times 10^3\ T_R}{kh} J</math>
+# Change the red <math> \frac{P}{z}</math> line to match the orange  <math> \frac{\bar{P}}{z}</math> curve
+## Change the GIIP
+## Change the intitial <math> \frac{P}{z}</math>
+# Change the flat [[JD]] gray line to match the changing [[JD]] gray line
+# Save the [[Gas Flowing Material Balance| FMB]] model
+# Move to the next well
+===Extra Plot to find b<sub>pss</sub>===
+#Calculate the initial pseudopressure, <math>P_{Pi}</math>
+#Calculate the material balance pseudo-time, <math>t_{ca}</math>
+#Plot <math>\frac{P_{P_i}-P_{P_{wf}}}{q_g}</math> versus <math>t_{ca}</math>
+#The intercept with the Y axis gives  <math>b_{pss}</math> and <math>J_D</math>
-=== Data required ===
+== Data required ==
-* Create [[Field]] [https://ep.pengtools.com/field/index  here]
-* Upload [[Well]]s [https://ep.pengtools.com/well/upload  here]
+{{Data required for Gas Flowing Material Balance}}
-* Upload [[Daily Measures]] [https://ep.pengtools.com/daily/measures/upload  here]
 == Nomenclature  ==
-:<math> A_p </math> = flow area, ft2
+:<math> b_{pss} </math> = reservoir constant, inverse to productivity index, psia<sup>2</sup>/cP/MMscfd
-:<math> B </math> = correlation group, dimensionless
+:<math> c </math> = compressibility, psia<sup>-1</sup>
-:<math> B </math> = formation factor, bbl/stb
+:<math> GIIP </math> = gas initially in place, MMscf
-:<math> C </math> = coefficient for liquid viscosity number, dimensionless
+:<math> G_p </math> = cumulative gas produced, MMscf
-:<math> D </math> = pipe diameter, ft
+:<math> J </math> = gas productivity index, MMscfd/(psia<sup>2</sup>/cP)
-:<math> h </math> = depth, ft
+:<math> J_D </math> = dimensionless productivity index, dimensionless
-:<math> H </math> = correlation group, dimensionless
+:<math> kh</math> = permeability times thickness, md*ft
-:<math> H_L </math> = liquid holdup factor, dimensionless
+:<math> P </math> = pressure, psia
-:<math> f </math> = friction factor, dimensionless
+:<math> \bar{P} </math> = average reservoir pressure, psia
-:<math> GLR </math> = gas-liquid ratio, scf/bbl
+:<math> P_P </math> = pseudopressure, psia<sup>2</sup>/cP
-:<math> M </math> = total mass of oil, water and gas associated with 1 bbl of liquid flowing into and out of the flow string, lb<sub>m</sub>/bbl
+:<math> q_g </math> = gas rate, MMscfd
-:<math> N_D </math> = pipe diameter number, dimensionless
+:<math> t </math> = time, day
-:<math> N_GV </math> = gas velocity number, dimensionless
+:<math> t_{ca} </math> = material balance pseudotime for gas, day
-:<math> N_L </math> = liquid viscosity number, dimensionless
+:<math> T </math> = temperature, °R
-:<math> N_LV </math> = liquid velocity number, dimensionless
-:<math> p </math> = pressure, psia
-:<math> q_c </math> = conversion constant equal to 32.174049, lb<sub>m</sub>ft / lb<sub>f</sub>sec<sup>2</sup>
-:<math> q </math> = total liquid production rate, bbl/d
-:<math> Re </math> = Reynolds number, dimensionless
-:<math> R_s </math> = solution gas-oil ratio, scf/stb
-:<math> SG </math> = specific gravity, dimensionless
-:<math> T </math> = temperature, °R or °K, follow the subscript
-:<math> v </math> = velocity, ft/sec
-:<math> WOR </math> = water-oil ratio, bbl/bbl
 :<math> z </math> = gas compressibility factor, dimensionless
 ===Greek symbols===
-:<math> \varepsilon </math> = absolute roughness, ft
 :<math> \mu </math> = viscosity, cp
-:<math> \rho </math> = density, lb<sub>m</sub>/ft<sup>3</sup>
-:<math> \bar \rho </math> = integrated average density at flowing conditions, lb<sub>m</sub>/ft<sup>3</sup>
-:<math> \sigma </math> = surface tension of liquid-air interface, dynes/cm (ref. values: 72 - water, 35 - oil)
-:<math> \psi </math> = secondary correlation factor, dimensionless
 ===Subscripts===
 :g = gas<BR/>
-:K = °K<BR/>
+:i = initial<BR/>
-:L = liquid<BR/>
-:m = gas/liquid mixture<BR/>
-:o = oil<BR/>
 :R = °R<BR/>
-:SL = superficial liquid<BR/>
+:wf = well flowing <BR/>
-:SG = superficial gas<BR/>
-:w = water<BR/>
 == References ==
 <references>
+<ref name=Mattar1998>{{cite journal
+ |last1=Mattar|first1=L.
+ |last2= McNeil |first2=R.
+ |title=The "Flowing" Gas Material Balance
+ |publisher=Petroleum Society of Canada
+ |journal=Journal of Canadian Petroleum Technology
+ |date=1998
+ |url=https://ihsmarkit.com/pdf/flowing-gas-material-bal-paper_228615110913049832.pdf
+}}</ref>
 <ref name=Mattar2005>{{cite journal
@@ Line 104: / Line 136: @@
 [[Category:E&P Portal]]
+{{#seo:
+|title=Gas Flowing Material Balance for GIIP calculation
+|titlemode= replace
+|keywords=giip calculation, reservoir engineering, flowing material balance, petroleum engineering, equation
+|description=Gas Flowing Material Balance is the advanced engineering technique applied to calculate reservoirs and wells GIIP and productivity index.
+}}

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Difference between revisions of "Gas Flowing Material Balance"

Latest revision as of 18:00, 3 November 2018

Contents

Brief

Math & Physics

Discussion