PTE599 Advanced Production Engineering

Final Project Report (Spring 2011)

Water Injection System for an Oil and Gas Production Operation: Calculations

Kevin Qi

Table 1: Well Information

Well

Top Perforation

(ft.)

Bottom Perforation

(ft.)

Injection Distance

(ft.)

Distance from

Pump (ft.)

Truck Distance

(ft.)1 5285 5376 5100 5807 7072 5306 5389 1000 1250 2503 5409 5475 200 1800 16004 5124 5179 1250 3150 19005 5374 5408 950 4150 32006 5356 5426 1325 6335 5010

Maximum Water Injection Pressure for each Well

Table 2: Maximum Water Injection PressuresWel

l Maximum Injection Pressure (Psi)1 1321.982 1327.633 1355.354 1278.665 1345.926 1341.08

Pump Capacity= 35400 bpd (given)

Figure 1: Standard Pipe Schedules and Sizes Chart Table Data

From chart, it can be gathered thatWith Schedule 80 line pipe6” PipelineWall thickness= .432”OD= 6.625”ID= 5.761”

3” PipelineWall Thickness=.3”OD=3.5”ID=2.9”

Pressure DropInjection Pipelines3”, Schedule 80 line pipeTable 3: Pressure Drop in Injection Pipelines

Well Length (ft.) Pressure Drop (psi)1 5100 198.52 1000 38.923 200 7.7844 1250 48.655 950 36.9756 1325 51.57

Truck Pipelines

6”, Schedule 80 line pipeTable 4: Pressure Drop in Truck Pipelines

Well Length (ft.) Q (bpd)

u,oil (ft/s) N,Re

1/SQRT(fM) fM

Pressure Drop (psi)

1 457 2950010.59632

1557367.03

18.1385302

1 0.0150976 12.83981435

2 250 3540012.71558

6668840.43

88.2000678

50.0148718

5 9.963274881

3 893 236008.477057

1445893.62

58.0553324

30.0154110

8 16.39075657

4 300 177006.357792

8334420.21

97.9351788

20.0158813

2 3.191867263

5 1300 118004.238528

5222946.81

37.7417627

50.0166847

7 6.458298619

6 1810 59002.119264

3111473.40

67.3524728

30.0184983

6 2.492333831

Fluid Velocity of the injection water at each junction point is given in column 4

Pump Discharge PressureTable 5: Pump Discharge Pressure

Well Discharge Pressure (psi)1 1543.282 1376.013 1402.334 1369.715 1431.766 1444.01

Table 6: Pressure DropWel

l Total Pressure Drop (psi) Actual Injection (psi)1 221.3 1378.72 48.88 1551.123 46.874 1553.1264 91.03 1508.975 85.815 1514.1856 102.91 1497.09

Figure 2: Baker Hughes Power Curve

Number of Stages for the PumpExtrapolate data from 35400 bpdHead Pressure= 68.5 psi/stage

Number of Stages = 1543.28psi/68.5psi/stage= 22.53= 23 Stages

Horse PowerExtrapolate data from 35400 bpdHP= 52 HP/StageTotal HP= 52HP/stage*23 stages= 1196 HP

Cost to OperateTotal kw=52HP/stage*23stage*.7457kw/HP=891.8572kwCost to Operate= .0515dollars/kwh*891.8572kw*24hrs*365days= $402,352.46 a year

Determine the Injection System for 35,400 bpd of Water InjectionBased on the above calculations, an injection system with a pump capacity of 35,400 bpd should have a discharge pressure of 1543.28 psi and total horsepower of 1196 HP. The head pressure per stage of the pump should be 68.5 psi/stage and the total head pressure of the wells should be 1370 psi. There should be a total of 23 stages. The cost of this injection system will be $402,352.46 a year.

PIPESIM Model Calculation

Inject well layout system is first recreated.

Figure 1: Well System

Parameters of tubing, pumps, and flow lines are then adjusted.

Figure 2: Tubing Parameters

Figure 3: Pump Parameters

After parameters are adjusted, the software can be run.

Figure 5: PIPESIM output

The pressure results from hand calculations are almost the same as the output given by the software. In addition, the actual injection pressure from the calculation and the inlet pressure of all the wells given by the software are very similar too. It can be concluded that the PIPESIM model confirms the calculations.