iagp neuquen 2008 production maintenance in mature fields how monitoring impacts production…

IAGP Neuquen 2008

Production Maintenance in Mature fields

How Monitoring Impacts Production…

2 - IAGP Neuquen 2008

Introduction

• Mature fields require an intensive monitoring in order to:

Understand the field behavior.

Characterize the reservoir

Detect opportunities to increase production and reserves workovers, stimulations, perforations, loops,

fractures, etc

Adjust dynamic models to provide accurate production forecasts and justify new projects

• BUT monitoring must be carefully chosen and followed from the very beginning of field

life

• “To much info kills info” each field requires a dedicated monitoring plan

• Operating costs must be kept under control as production is declining get the right data at the right time

• Examples of specific monitoring actions that had impact on production and reserves

Aguada Pichana: new fracture methodology adapted to heterogeneously depleted reservoir

San Roque: well performance actions to fill a production gap


Neuquen Basin – Aguada Pichana BlockNeuquen Basin – Aguada Pichana Block

SCHEMATICSCHEMATIC SECTIONSECTIONPrecuyo

Molles

Lajas

Auquilco + Lotena

Tordillo

Mulichinco

Agrio

Rayoso+

Huitrin

CR

ET

AC

EO

US

JUR

AS

SIC

Quintuco+

Vaca Muerta

Precuyo

Molles

Lajas

Auquilco + Lotena

Tordillo

Mulichinco

Agrio

Rayoso+

Huitrin

CR

ET

AC

EO

US

JUR

AS

SIC

Quintuco+

Vaca Muerta

Neuquen Basin Neuquen Basin

Sedimentary columnSedimentary column

Permeable Sandstones

Low – Very Low Permeability Sandstones

Low Permeability Sandstones (high Microporosity)

Shale to non reservoir Siltstone

Limestone to Calcareous Sandstone

Low Permeability Sandstones (high Microporosity-Aeolian Facies)

Sequence Boundary

ReferencesReferencesPermeable Sandstones






Sequence Boundary

Permeable Sandstones






Sequence Boundary

ReferencesReferences

The Aguada Pichana field is located in the Neuquén Basin, south-western

Argentina.

The field produces gas from the sandstones of the Mulichinco formation, its

main reservoir.

Aguada Pichana is the second largest gas field in Argentina

It is developed in the eastern flank of the NW-SE trending positive structure

called Chihuido anticline.

The Mulichinco Fm depths ranges between : 1600 / 1800 mMD


Aguada Pichana Production History

PROBLEMATIC

• Low/Med perm. / heterogeneous sands • Strong natural decline• Intense drilling campaign (3 to 4 wells per month)

• New wells towards the West (low K)• Necessity of LP compression• Complex coordination with multiple constraints

• Hydraulic fractures systematically required

Aguada Pichana development wells

A P -2 2 5

A P -2 2 2

A P -2 2 0:

A P -2 2 3

A P -1 8 7

A P -2 1 9 :

2.470 2.475 2.480 2.485 2.490 2.495

Mi l l ions

COMEX 1994 & 2005

COMEX 2005 drilled in 2006

COMEX 2005 to be drilled in 2007

Additional wells 2007

k=20-50mD

k=5-10mD

k=1-5mD

K<1mD0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Ene-99 Ene-00 Ene-01 Ene-02 Ene-03 Ene-04 Ene-05 Ene-06 Ene-07 Ene-08 Ene-09

Ex

po

rt G

as

(M

Mm

3/d

)

Wells 1999

Wells 2000

AP-136

Start up MP compressión

Wells 2004 (10)

Wells 2005 (24)

Wells 2006 (34)

Wells 2007 (34)

Start up LP


How to maintain the production plateau in AP ?

Continuous monitoring actions such as:

Well tests, Isochronal tests, MDT, PLT, fluid sampling, seismic surveys

allowed to define:

1. Drilling Campaign extensions thanks to adequate coring program and dedicated 3D seismic survey

• infill & delineation wells

• Step out wells

2. Production Optimizition & stimulations actions

• MP & LP compression inline with expectations thanks to an adapted monitoring and a good model history match

• New fracture design (wells without fracture don’t produce)

3. Future development projects in AP Block being studied

• LLP compression

• Well spacing reduction

• Low permeability reservoirs how to produce them economically ?


Well: AP-193

DATE PLOTTED: 03-Mar-2006

HORIZONTAL UNITS: METRES

Y COORDINATE: -

X COORDINATE: -

LONGITUDE: 69.0000

LATITUDE: 38.0000

LOCATION: X

COMPANY: Total Austral

VERTICAL SCALE: 1:500

DATE LOGGED: 03-Mar-2006

VERTICAL UNITS: METRES

DRILLED DEPTH: -

ELEVATION MEAS. REF.: -

MEASUREMENT REF.: DRILL FLOOR

SURFACE ELEVATION: -

DATUM FOR ELEVATION: GROUND LEVEL

RM

- @ -

RMC

- @ -

RMF

- @ -

DFD

-

BHT

- -

DEPTH (METRES)

1625.00-1742.00 -

SHT BIT S IZE

Composite

1650

1675

1700

1725

DEPTHMETRES

MULTIMIN.VOL_ILLITE_10 1

MULTIMIN.VOL_CALCITE_10 1

MULTIMIN.VOL_QUARTZ_10 1

MULTIMIN.VOL_ORTHOCL_10 1

MULTIMIN.VOL_UBNDWAT_10 1

1650

1675

1700

1725

1625.0

1742.0

DEPTH

1635.0

UPP MULI24.0

1659.0

MID MULI61.0

1720.0

LOW MULI17.0

1737.0

MULTIMIN.VOL_UIRRWAT_1V/V0.5 0

MULTIMIN.VOL_UFREWAT_1V/V0.5 0

MULTIMIN.VOL_UGAS_1V/V0.5 0

multimin.vol_uoilV/V0.5 0

MULTIMIN.VOL_UBNDWAT_1V/V0.5 0

MULTIMIN.PHIT_1V/V0.5 0

MULTIMIN.RHOG_1G/C32.6 3.1

MULTIMIN.KTIM_1MD0.01 1000

CMR.KTIM_1MD0.01 1000

mdt.mobility_1MD/CP0.01 1000

MULTIMIN.SWT_1V/V1 0

MULTIMIN.SWE_1V/V1 0

MULTIMIN.VOL_UWAT_1V/V0.5 0

MULTIMIN.PHIE_1V/V0.5 0


CMR.CBP3_1V/V0.5 0

CMR.CBP4_1V/V0.5 0

CMR.CMRP_3MS_1V/V0.5 0

CMR.CBP1_1V/V0.5 0

CMR.CBP2_1V/V0.5 0

1650

1675

1700

1725

DEPTHMETRES

WIRE.HCAL_1IN5 15

WIRE.SP_1MV-80 20

WIRE.GR_1GAPI0 200

CMR.GR_1GAPI0 200

WIRE.TNPH_1V/V0.45 -0.15

WIRE.RHOZ_1G/C31.95 2.95

WIRE.HDRA_1G/C3-0.4 0.1

WIRE.U_1

B/C30 20

WIRE.PEFZ_1

B/E0 10

WIRE.AHT10_1

OHMM0.2 2000

WIRE.AHT20_1

OHMM0.2 2000

WIRE.AHT60_1

OHMM0.2 2000

WIRE.AHT90_1

OHMM0.2 2000

WIRE.DTCO_1

US/F140 40

PLT

60%

40%

Well: AP-193



Y COORDINATE: -

X COORDINATE: -

LONGITUDE: 69.0000

LATITUDE: 38.0000

LOCATION: X





DRILLED DEPTH: -





RM

- @ -

RMC

- @ -

RMF

- @ -

DFD

-

BHT

- -

DEPTH (METRES)

1625.00-1742.00 -

SHT BIT S IZE

Composite

1650

1675

1700

1725

DEPTHMETRES






1650

1675

1700

1725

1625.0

1742.0

DEPTH

1635.0

UPP MULI24.0

1659.0

MID MULI61.0

1720.0

LOW MULI17.0

1737.0
















CMR.CBP3_1V/V0.5 0

CMR.CBP4_1V/V0.5 0


CMR.CBP1_1V/V0.5 0

CMR.CBP2_1V/V0.5 0

1650

1675

1700

1725

DEPTHMETRES

WIRE.HCAL_1IN5 15

WIRE.SP_1MV-80 20

WIRE.GR_1GAPI0 200

CMR.GR_1GAPI0 200




WIRE.U_1

B/C30 20

WIRE.PEFZ_1

B/E0 10

WIRE.AHT10_1

OHMM0.2 2000

WIRE.AHT20_1

OHMM0.2 2000

WIRE.AHT60_1

OHMM0.2 2000

WIRE.AHT90_1

OHMM0.2 2000

WIRE.DTCO_1

US/F140 40

PLT

60%

40%

AP: Fracture design optimization Continuous monitoring actions in order to identify possible “bottlenecks of potential”:

Well: AP-193



Y COORDINATE: -

X COORDINATE: -

LONGITUDE: 69.0000

LATITUDE: 38.0000

LOCATION: X





DRILLED DEPTH: -





RM

- @ -

RMC

- @ -

RMF

- @ -

DFD

-

BHT

- -

DEPTH (METRES)

1625.00-1742.00 -

SHT BIT SIZE

Composite

1650

1675

1700

1725

DEPTHMETRES






1650

1675

1700

1725

1625.0

1742.0

DEPTH

1635.0

UPP MULI24.0

1659.0

MID MULI61.0

1720.0

LOW MULI17.0

1737.0
















CMR.CBP3_1V/V0.5 0

CMR.CBP4_1V/V0.5 0


CMR.CBP1_1V/V0.5 0

CMR.CBP2_1V/V0.5 0

1650

1675

1700

1725

DEPTHMETRES

WIRE.HCAL_1IN5 15

WIRE.SP_1MV-80 20

WIRE.GR_1GAPI0 200

CMR.GR_1GAPI0 200




WIRE.U_1

B/C30 20

WIRE.PEFZ_1

B/E0 10

WIRE.AHT10_1

OHMM0.2 2000

WIRE.AHT20_1

OHMM0.2 2000

WIRE.AHT60_1

OHMM0.2 2000

WIRE.AHT90_1

OHMM0.2 2000

WIRE.DTCO_1

US/F140 40

Well: AP-193



Y COORDINATE: -

X COORDINATE: -

LONGITUDE: 69.0000

LATITUDE: 38.0000

LOCATION: X





DRILLED DEPTH: -





RM

- @ -

RMC

- @ -

RMF

- @ -

DFD

-

BHT

- -

DEPTH (METRES)

1625.00-1742.00 -

SHT BIT SIZE

Composite

1650

1675

1700

1725

DEPTHMETRES






1650

1675

1700

1725

1625.0

1742.0

DEPTH

1635.0

UPP MULI24.0

1659.0

MID MULI61.0

1720.0

LOW MULI17.0

1737.0
















CMR.CBP3_1V/V0.5 0

CMR.CBP4_1V/V0.5 0


CMR.CBP1_1V/V0.5 0

CMR.CBP2_1V/V0.5 0

1650

1675

1700

1725

DEPTHMETRES

WIRE.HCAL_1IN5 15

WIRE.SP_1MV-80 20

WIRE.GR_1GAPI0 200

CMR.GR_1GAPI0 200




WIRE.U_1

B/C30 20

WIRE.PEFZ_1

B/E0 10

WIRE.AHT10_1

OHMM0.2 2000

WIRE.AHT20_1

OHMM0.2 2000

WIRE.AHT60_1

OHMM0.2 2000

WIRE.AHT90_1

OHMM0.2 2000

WIRE.DTCO_1

US/F140 40

1. Increased average gas rate (~20%)

2. Accelerate reserves

3. Average skin = -5 against -3 previously

Monitoring & new fracture design:

•Gas potential evolution: production tests

•Reservoir pressure evolution: statics gradients & MDT acquisition in every new well

•Isochronal test after frac transmissibility / Skin / Xf

• Thanks to monitoring, it was possible to see that some wells didn’t show

the expected fracture behavior and the corresponding productivity

• By Integrating the MDT data (differential depletion) + rock mechanics in

our designs, it was possible to optimize the treatment with dedicated

fractures to avoid convection and disconnection between frac and

wellboreOld fracture design New fracture design

Disconnection of frac due to convection

Perf

•High K zone

•Depleted zone

• Lower K zone

• Pressurized zone

Main results

1 6 60

m

MD

1 6 80

1 7 00

1 7 20

N P H I V/V0 .4 5 -0 .1 5 0 00 .1 5

R H OZ G/C 31 .9 5 2 .9 52 .4 5

13 2 1 6 71 5 0

KTIM_ G6 MD0 .1 0 1 0 0

0.1 - 3 mD (avg)

low depletion

3 - 10 mD (avg)

Strong depletion

1 6 60

m

MD

1 6 80

1 7 00

1 7 20

N P H I V/V0 .4 5 -0 .1 5 0 00 .1 5

R H OZ G/C 31 .9 5 2 .9 52 .4 5

13 2 1 6 71 5 0

KTIM_ G6 MD0 .1 0 1 0 0

0.1 - 3 mD (avg)

low depletion

3 - 10 mD (avg)

Strong depletion

Typical MDT + permeability log in AP


Neuquen Basin San Roque Block

PROBLEMATIC

• Intrusive sills: volcanic sills naturally fractured

• Shallow sills (LLY, F3C): Rich gas and oil

• Deep sills (Rincon Chico) : Dry gas HP/HT

• Shallow Clastics (Centenario / Mulichinco)

6

7

8

9

10

11

12

13

Oct

-03

Dec

-03

Feb

-04

Ap

r-04

Jun

-04

Au

g-0

4

Oct

-04

Dec

-04

Feb

-05

Ap

r-05

Jun

-05

Au

g-0

5

Oct

-05

Dec

-05

Feb

-06

Ap

r-06

Jun

-06

Au

g-0

6

Oct

-06

Dec

-06

Feb

-07

Ap

r-07

Mill

ion

s

Exp

ort

Gas

@ C

al r

eal

MP Start

Withoutpotenti

ASR Block Gas export

ASR

LLY

RCh


How to maintain the production plateau in ASR ?

1. Continuous monitoring actions:

• Well tests, Flow after flow tests, PLT, etc

2. Production optimization & stimulations actions

• Nodal Analysis: tubing resizing, loops, etch.

• MP & LP compression

• Optimizing selective completions in ASR clastics wells

• Acid stimulation with balls sealers: necessary in all filons target

• Re-perforations / re-stimulations with new acids treatments.

3. Future studies in ASR Block

• New technologies (batch fracs, new acids, local compression,…)

• Infill targets based on revised and history matched models

• New stimulation campaign based on recent success on filones


Aguada San Roque Clastics: Production Optimisation Example

Centenario C

Centenario A

Mulichinco

Optimization: based on good initial data per layer + pressure monitoring in neighboring wells, a multi layer nodal analysis was performed low risk of crossflow and potential production gain was identified

• Best configuration was found (M + Cent A + Cent C)

• Significant production increase was achieved

Gain: + 110 Km3/d from M + Cent A + Cent CASR-034

0

50,000

100,000

150,000

200,000

250,000

300,000

Aug-06 Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Feb-07 Mar-07 Apr-07 May-07 Jun-07 Jul-07 Aug-07

Ga

s R

ate

(m

3/d

)

M

CC

CAM

MMM

CC: 35 %CA: 55 %M: 10 %

10

- IAGP Neuquen 2008

San Roque : another production optimisation example

• Incremental production : 70 KSm3/d

0

50

100

150

200

250

300

350

400

Jan

-00

Dec-0

0

Dec-0

1

Dec-0

2

Jan

-04

Dec-0

4

Dec-0

5

Dec-0

6

Jan

-08

Dec-0

8

Dec-0

9

Dec-1

0

Jan

-12

Dec-1

2

Dec-1

3

Dec-1

4

Jan

-16

Dec-1

6

Ga

s R

ate

(K

m3

/d)

Without WO

With WO

Test

Bad tests

MP WO

LP

Tubing Change

1. Flow after flow PI diagnosis

2. Analysis nodal Prod performance

3. Workover (2 7/8” 4 ½”)

4. Re-perforation + acid job to be done shortly

Tubing change + acid job + ball sealers + Loop

1. Add perforations + acid job + ball sealers

2. Analysis nodal

3. Workover (2 7/8” 4 ½”)

4. New analysis nodal

5. Loop

0

100

200

300

400

500

600

700

800

900

1,000

En

e-9

7

En

e-9

8

En

e-9

9

En

e-0

0

En

e-0

1

En

e-0

2

En

e-0

3

En

e-0

4

En

e-0

5

En

e-0

6

En

e-0

7

En

e-0

8

En

e-0

9

Ga

s R

ate

(K

m3

/d)

Perf + acid

WOLoop

MP

• Incremental production : 600 Km3/d

Due the complexity of the ASR & LLY fields (filones), acid jobs with ball sealers are necessary in order to stimulate all the opened fractures. In the same way, reperforations jobs enhace access to new fractures.

A typical workflow in ASR block is:


San Roque Actions: Impact on production profile

8

9

10

11

12

13Ja

n-0

6

Feb

-06

Mar

-06

Ap

r-06

May

-06

Jun

-06

Jul-

06

Au

g-0

6

Sep

-06

Oct

-06

No

v-06

Dec

-06

Jan

-07

Feb

-07

Mar

-07

Ap

r-07

May

-07

Jun

-07

Jul-

07

Au

g-0

7

Sep

-07

Oct

-07

No

v-07

Dec

-07

Jan

-08

Feb

-08

Mar

-08

Ap

r-08

May

-08

Jun

-08

[MM

m3/

d @

930

0 kc

al]

Gas Sales Gas Potential

Export Plant capacity 12.1 MMm3/d

Export Plant capacity 12.3 MMm3/d

MP plannedstart up

ASR-58WO

MP start up

Plant fire #3 & #4 closed

Wells close:WO ASR-36/104

LLY-203/20

Open sleevesASR-58/34

LLY-216Perf UMZ

New wellsASR-201 / 203

LLY-219 / LLY-202Perf UMZ + Acid

ASR-36 Acid

LLY-218Perf UMZ + Acid

LLYH-208Perf UMZ + Acid

Export Plant capacity 12 MMm3/d

Δ ~ 1.5 MMm3/d

12

- IAGP Neuquen 2008

Conclusions

11 Aguada Pichana:

Extend production plateau and compensate the strong decline of the field (400 / 450 Km3/d every month)

Identify new zones of interest (conventional or not)

Debottleneck surface facilities and well architecture when required

Design a new fracture methodology to increase production and push upwards the recovery factor

Prepare the future (new drilling campaigns and/or developments, LLP, spacing reductions)

San Roque Extend the production plateau until LP compression start up

Debottleneck surface facilities and well architecture when required

New stimulations design potential stimulation campaign could be triggered

2. A monitoring plan is a fundamental part of a Field Development Plan. It allows to:

• Understand the field, anticipate actions and react in time in any situation

• Update our models (static and dynamic) for more robust reserves estimates

• Identify potential upsides and reduce risks for future projects

The actions carried out as consequence of the monitoring have allowed us to:

13

- IAGP Neuquen 2008

Final Word: Integration of disciplines is key

Well Performance Team

Well Completion Reservoir

Production / Surface facilities

iagp neuquen 2008 production maintenance in mature fields how monitoring impacts production…

Documents

aguada pichana field

iagp neuquen

production maintenance

production gap

reserves aguada pichana

field behavior

accurate production

intensive monitoring