17.00 soliman

presentation to Repsol by MYS on 9/13/06

Well Completion Design for Tight-Gas Formations

M. Y. Soliman, PhD

September 20, 2006

Mendoza, Argentina

presentation to Repsol by MYS on 9/13/06

Completion of Tight gas sand

• Various completion options• Fluid Flow• GeoMechanics

presentation to Repsol by MYS on 9/13/06

presentation to Repsol by MYS on 9/13/06

Successful Completion Optimization

• Set up realistic expectations• Consider various completion options

presentation to Repsol by MYS on 9/13/06

Successful Completion Optimization

• Set up realistic expectations– Reservoir Characterization

• Well tests, Logging, and core data

• production analysis of offset well

• Stress field

– Understanding of reservoir fluid properties

– Realistic modeling

presentation to Repsol by MYS on 9/13/06

Successful Completion Optimization

• Optimize completion– Various completion strategy

– Set optimization criterion or criteria

– Define parameters that affect the optimum design• Fracture geometry, conductivity, height• Reservoir properties

– Realistic modeling

presentation to Repsol by MYS on 9/13/06

Some of the Possible completion types

• Vertical well• Fractured vertical well• MLT

– Radially distributed, kicked off in the middle of the formation– Vertical distribution

• Fractured horizontal well

presentation to Repsol by MYS on 9/13/06

presentation to Repsol by MYS on 9/13/06

presentation to Repsol by MYS on 9/13/06

Investigated properties

• Permeability 0.005, 0.05, 0.1 md• Height 400 ft, also looked at 100 and 20 ft• Pressure 4000 psi• Fracture Parameters

– half length 400 ft, Conductivity, 1750 md-ft

• MLT – 6 arms 550 ft each + the vertical well

• Horizontal well, – 1320 ft – Four fractures

presentation to Repsol by MYS on 9/13/06

Effect of completion type

Total Production Comparison - 400-ft formation, k=0.1 md

0.00E+00

5.00E+00

1.00E+01

1.50E+01

2.00E+01

2.50E+01

3.00E+01

3.50E+01

4.00E+01

4.50E+01

5.00E+01

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time, days

Cu

mu

lati

ve

Pro

du

cti

on

, B

cf

Vertical w ell

Fractured V Well

Fractured H WellMLT- Horizontal

MLT- Vertical

presentation to Repsol by MYS on 9/13/06

Effect of completion type

Total Production Comparison - 400-ft formation, k=0.05 md

0.00E+00

5.00E+00

1.00E+01

1.50E+01

2.00E+01

2.50E+01

3.00E+01

3.50E+01

4.00E+01

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time, days

Cu

mu

lati

ve P

rod

uct

ion

, Bcf

Vertical w ellFractured V WellFractured H WellMLT- HorizontalMLT- Vertical

presentation to Repsol by MYS on 9/13/06

Effect of completion type

Total Production Comparison - 400-ft formation, k=0.005 md

0.00E+00

2.00E+00

4.00E+00

6.00E+00

8.00E+00

1.00E+01

1.20E+01

1.40E+01

1.60E+01

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time, days

Cu

mu

lati

ve P

rod

uct

ion

, B

cf

Vertical w ellFractured V WellFractured H WellMLT- HorizontalMLT- Vertical

presentation to Repsol by MYS on 9/13/06

Vertical Well Pressure Distribution

presentation to Repsol by MYS on 9/13/06

Fractured Vertical Well pressure Distribution

presentation to Repsol by MYS on 9/13/06

MLT pressure

Distribution

presentation to Repsol by MYS on 9/13/06

Cross section

presentation to Repsol by MYS on 9/13/06

Frac HW pressureDistribution

presentation to Repsol by MYS on 9/13/06

Refrac and multiple Fractures

• One fracture• Two perpendicular fractures• Multiple fractures.

presentation to Repsol by MYS on 9/13/06

Cumulative production comparison for one and two fracs

0

200

400

600

800

1000

0 500 1000 1500 2000

Time, days

To

tal

Pro

du

ctio

n,

mm

cf

Single Frac

Two fracs

presentation to Repsol by MYS on 9/13/06

One-Frac case

presentation to Repsol by MYS on 9/13/06

Two-Frac case

presentation to Repsol by MYS on 9/13/06

GeoMechanics effect

• Depletion• Stress interference

presentation to Repsol by MYS on 9/13/06

0

5

10

15

20

25

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Time, days

To

tal

pro

du

cti

on

, b

cf

base Case

Effect of porosity

Effect of permeability

Combined effect

Effect of pressure dependant permeability and porosity

presentation to Repsol by MYS on 9/13/06

Stress Interference in Fractured Horizontal Well

1.0

1.5

2.0

2.5

3.0

0.50 0.60 0.70 0.80 0.90 1.00

Dimensionless Distance between Fractures, L / h

Rat

io o

f N

et F

ract

uri

ng

Pre

ssu

re Fracture 5

Fracture 2

Fracture3

Fracture 4

presentation to Repsol by MYS on 9/13/06

Annulus Pressure, Tubing Rate, & Annulus Rate

7/10/200309:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00

7/10/200318:00

Time

0

500

1000

1500

2000

2500

3000A

(psi)

0

5

10

15

20

25

30

35

40C

(bpm)

Annulus Pressure (psi) Slurry Rate (bpm) Flowback Rate (bpm)A C C

presentation to Repsol by MYS on 9/13/06

Conclusions

• The lower the permeability, the more attractive fracturing.

• Fracturing horizontal wells is the most promising technique in thick, tight gas formations.

• The geomechanics effect on complex reservoir performance should always be considered, especially when creating multiple fractures in horizontal wells

• Multiple fracturing from a wellbore is a fast growing area of technology