Page 84 - Petroleum Production Engineering, A Computer-Assisted Approach

Guo, Boyun / Computer Assited Petroleum Production Engg 0750682701_chap06 Final Proof page 76 3.1.2007 8:40pm Compositor Name: SJoearun

6/76 PETROLEUM PRODUCTION ENGINEERING FUNDAMENTALS
Table 6.5 Solution Given by WellheadNodalGas-SonicFlow.xls
WellheadNodalGas-SonicFlow.xls
Description: This spreadsheet calculates well deliverability with wellhead node.
Instructions:
Step 1: Input your data in the Input data section.
Step 2: Click Solution button to get results.
Step 3: View results in table and in the plot graph sheet.
Input data
Gas-specific gravity (g g ): 0.71
Tubing inside diameter (D): 2.259 in.
Tubing relative roughness («=D): 0.0006
˙
Measured depth at tubing shoe (L): 10,000 ft
Inclination angle (u): 0 degrees
Wellhead choke size (D ck ): 16 1/64 in.
Flowline diameter (D fl ): 2 in.
Gas-specific heat ratio (k): 1.3
Gas viscosity at wellhead (m g ): 0.01 cp
Wellhead temperature (T hf ): 120 8F
Bottom-hole temperature (T wf ): 180 8F
Reservoir pressure (p ): 2,000 psia
C-constant in back-pressure IPR model: 0:01 Mscf=d-psi 2n
n-exponent in back-pressure IPR model: 0.8
Solution
T av ¼ 610 8R
Z av ¼ 0.8786
s ¼ 0.4968
e s ¼ 1.6434
f m ¼ 0.0174
AOF ¼ 1,913 Mscf/d
D ck =D fl ¼ 0.125
Re = 8,348,517
C ck ¼ 1:3009 in: 2
A ck ¼ 0.0490625
q sc (Mscf/d) WPR CPR
0 1,600 0
191 1,554 104
383 1,489 207
574 1,411 311
765 1,321 415
956 1,218 518
1,148 1,099 622
1,339 960 726
1,530 789 830
1,721 562 933
1,817 399 985
1,865 282 1,011
1,889 200 1,024
1,913 1 1,037
Operating flow rate ¼ 1,470 Mscf/d
Operating pressure ¼ 797 psia

Example Problem 6.6 Use the following data to estimate Wellhead temperature: 100 8F
the liquid production rate of an oil well: Tubing shoe depth: 12,000 ft
Bottom-hole temperature: 150 8F
Reservoir pressure: 6,000 psia
Tubing ID: 3.5 in. Solution Example Problem 6.6 is solved with the
1
Choke size: 64 ⁄ 64 in. spreadsheet program WellheadNodalOil-PC.xls. Table 6.6
Productivity index above bubble point: 1 stb/d-psi shows the appearance of the spreadsheet for the Input data
Producing gas–liquid ratio (GLR): 1000 scf/stb and Result sections. The inflow and outflow performance
Water cut: 25% curves are plotted in Fig. 6.4, which indicates that the
Oil gravity: 30 8API expected oil flow rate is 3280 stb/d at a wellhead pressure
Water-specific gravity: 1.05 1 for fresh- of 550 psia.
water If the reservoir pressure is below the bubble-point
Gas-specific gravity: 0.65 1 for air pressure, Vogel’s IPR can be rearranged to be
Choke constant: 10 " s ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi #
Choke GLR exponent: 0.546 q
Choke-size exponent: 1.89 p wf ¼ 0:125 p p 81 80 1 (6:21)
q max
Formation volume factor of oil: 1 rb/stb