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


Completion of Tight gas sand

• Various completion options• Fluid Flow• GeoMechanics


Successful Completion Optimization

• Set up realistic expectations• Consider various completion options



• 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



• 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


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


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


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




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




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


Vertical Well Pressure Distribution


Fractured Vertical Well pressure Distribution


MLT pressure

Distribution


Cross section


Frac HW pressureDistribution


Refrac and multiple Fractures

• One fracture• Two perpendicular fractures• Multiple fractures.


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


One-Frac case


Two-Frac case


GeoMechanics effect

• Depletion• Stress interference


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


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


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


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

17.00 soliman

Documents

completion design

fractures presentation

tightgas formationsm

vertical wellhorizontal

criteriadefine parameters