APPLICATION OF INNOVATIVE TECHNOLOGIES TO PHASE OUT SWD IN SOUTH OMAN

Rashid Al-MasfryInnovative Water & Wastewater Technologies Workshop,

SAWEA 29-30th of November 2005

Email:

rashid.masfry@shell.com

Extended list:

PDO: Mohamed Al-Lamki

Shell: Paul Verbeek, Maarten Schaapveld, Ewout Biezen, Jip van Eijden, Paul van den Hoek

PRESENTATION OVERVIEW• Case for Phasing out SWD….?• PDO Water Management Principles• Approach used to handle PW water:

– Reservoir: Water Shut Off-Mechanical/Chemical– Wellbore: Downhole Seperation and Wellbore control– Surface/Subsurface:

– Utilising water to enhance hydrocarbon recovery by Water Injection– Dispose off surplus into deep horizon by Deep Water Disposal

– Surface:– Taking opportnity to green the desert by Reedbed and;– Desalination of produced waterd by Solar Dew

PDO PW PROFILE: Injection and disposal

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032

Wat

er ra

te [m

3/d]

Water productionWater injectionPPB '04PPB '04Water disposal

Shallow Water Disposal Aquifers

PDO SALINITY DISTRIBUTION

Fars and UeR Salinities

< 1000 ppm

Potable water in the south area

High salinity region

AQUIFER RECHARGE & SEA WATER

South

DHOFARMOUNTAINS

SeaLevel Umm Er Radhuma

Haushi(Gharif)

Nahr Um

Haima?

CENTRAL OMANHIGH

SOUTH OMAN SALT BASIN

BIRBA HIGH

200 km

2 km NORTH OMAN SALT BASIN

OMANMOUNTAINS

North

Aquifers of Oman

Dr. No. : 105822 PC

Author : X

EM

/31D

ate : October 2001

Fig. :D

r. No. : 15822 P

C

Produced Water and Shallow Water Salinity ComparisonFormation/ Water Type

MarmulTDS (ppm)

Nimr(TDS ppm)

Rima(TDS ppm)

TDS (ppm) of Fresh Water Lens

1,800 - 2,000 600 - 1,800 160 - 350

Fars - 600 - 5,500 160 - 7,000

Dammam 1,800 - 2,000 - 7,000 -12,000

Fars + Dammam - 1,300 - 8,000 7,000 - 14,500

Rus 4,000 - 5,000 4,000 - 9,000 -

Rus + UeR - 5,000 - 8,000 8,000 - 11,000

UeR 1,000 - 6,500 5,000 - 7,500 8,000 - 14,000

Disposed Water (TDS)

4,000 - 4,500 7,000 - 8,000 10,000 - 13,000

SWD Depths 50 – 150 mbgl 90 – 160 mbgl 300 – 650 mbgl

SWD Formation Dammam + Rus Fars + Dammam UeR

Fresh water Lens UeR in Sabsab, (Western asset),

Localised lenses inDammam

Fars/Dammam Fars/Dammam

KEY SUSTAINABLE PRINCIPLES

Minimise water volumes produced to surface

Return water to producing reservoir for increased oil production or disposal

Maximise water re-use at surface

Safeguard open waters & fresh water aquifer

Water Management Approach

• Re-use:• Taking opportunity to green the desert by Reedbed• Desalination of produced water by Solar Dew

•Reduce:•Water Shut Off-Mechanical/Chemical (Profile control and diversion)•Downhole Separation

•Re-inject:•Dispose off surplus into deep horizon by Deep Water Disposal•Utilising water to enhance hydrocarbon recovery by Water Injection

WATER LIFE CYCLE and VARIOUS TECHNOLOGIESCompact Fluid

Separators

D ownhole S eparation

Deep WellInjection/disposal

Induced Fracture

Water Shut-off

DH Metering & Control

Surface disposal

Offshore Water Discharge

Water Aquifer

Compact Fluid Separators

D ownhole S eparation

Deep Well

Induced Fracture

Water Shut-off

DH Metering & Control

Surface disposal

Offshore Water Discharge

Fresh Water Aquifer

ProducerInjector

Reduce water: By Shallow perforation Shut-off

• ADIPEC 2004: Gel-Cement system described in SPE 88765

Reduce water by Shut-off NaturalFractures and Faults While Drilling

Reduction of Produced Water at the Source

Benefits include:reduction in Mud losses

enabling low draw down production contributing to delaying water coning

improving oil production

Cross-sectional view

v

v

injectedchemical

forfractureshut-off

matrix

fracture

Reduce water by Downhole Separation

Results

Production zone,

1543mah-2013mahInjection zone

1415m TVD

1470m TVD

4 1/2” liner

7” liner

9 5/8” casing

2 7/8” injection tubing2 7/8” liner

Pump intake

REDA AQWANOT

1050m TVD

Dual port packer1120m TVD

OIW: injected water quality is 35ppm

Additional Oil 40 m3/d (drawdown & stimulation)

(Rates in m³/d)

Before DHOWS up to June 2000

With DHOWS 25 Feb 2001

Downhole equipment ESP ESP Gross rate 717 277 Oil to surface 77 118 Water to surface 640 159 Water injected 0 approx. 700 Surface watercut 89.3 57.4

Bulk water removal for PWRI by compact separation (10,000m3/d gross)

Re-inject water: Nimr Area and south of PDO

N

NRPS

DWD Phase 1(Site 1)

SWD Wells

32”Pipeline32”Pipeline

32”Pipeline

All Produced Water

Site Number of Pumps / Wells Site Capacity

Site 1 2 Pumps3 Wells

45,000 m3 /day

Site 22 Pumps3 Wells 43,000 m 3/day

Site 34 Pumps5 Wells 90,000 m 3/day

Site 4 4 Pumps6 Wells

90,000 m 3/day

Total 12 Pumps20 Wells

268,000 m 3/day

DWD Phase 2(Site 2)

DWD Phases 3 & 4(Site 3)

DWD Phases 5 & 6(Site 4)

Re-inject water: : General Nimr Disposal Schemes

Re-inject water: DEEP WATER DISPOSAL

Re-inject water: Deep Aquifers and DWD

Re-inject water: Matrix vs Fractured injection Analysis

Parted Pressure(PP)

W ater Injection Rate, Q w

Inje

cti o

n Pr

essu

r e, P

i

M atrix Injction

Fractured Injection

Parted Pressure(PP)

W ater Injection Rate, Q w

Inje

cti o

n Pr

essu

r e, P

i

M atrix Injction

Fractured Injection

Re-inject water: Data Analysis of South Well

Hall plot of NM-373 showing response to hydraulic fracturing job

RE-INJECT WATER: INDUCED FRACTURE MODELING RE-INJECT WATER: INDUCED FRACTURE MODELING

PWRI-FRAC:• Frac size• Skin• BHP (frac prop) MoRes:

• Well productivity• 3D pressure • UR

353

355351

354

Re-use water: Flow Scheme Greening the Desert

Pre-treatment ?

Water from Dehydration System

•Reed Beds

•Solar Dew

•Bioremediation ponds

•Other

Bio-treatment

(Bio-saline) irrigation Beneficial biomass

Re-use water: Nimr Reed Beds Experimental Plot

Biosaline Plot

Solar Dew

Reed BedsB1

B2

B3

B4

A1

A2

A3

A4

Spray pond

Evap.pond A

Evap.pond B

Scale: 6 hectares in total

Biosaline agriculture

C1

Solar Dew water plant

Fresh water agriculture

Reed Beds

C2

C3

C4

B1

B2

B3

B4

A1

A2

A3

A4

Spray pond

Evap.pond AEvap.pond A

Evap.pond B

Evap.pond B

Scale: 6 hectares in total

Biosaline agriculture

C1

Solar Dew water plant

Fresh water agriculture

Reed Beds

C2

C3

C4

Q: 250 m3/dayFeed: OiW 200-300 mg/l;

TDS 6-8,000 mg/lOutlet: OiW 0-5 ppm

TDS ~8-10,000 mg/lMetals removal: up to 90%Residence time: 5-6 days

11 months old Acacia plantsSeveral species tested; survivors mainly tree species

• Water quality meets WHO drinking water standard (Q ~ 4.5 liter/m2/d)• Influent: O-i-W~10 ppm, salinity of 32,000 ppm (evap. pond) • Effluent O-i-W ~ 0 ppm, salinity of 1,000 ppm (fresh water) • Selectivity for Boron proven; VOC, BTEX, phenols undetectable

Other ideas: Inter Asset Water Utilisation Trans Oman Water Line

Nimr

MukhaisnaSteam

Bahjawater Floods

QA Steam

YibalAl HuwaisahWater floods

Lekhwair

Business case…

Enhanced recovery steam/waterfloods

Protect exploitable ground water

Save groundwater abstraction costs

Open water supply to communities (Bio-saline and solar dew)

Stage 1

Stage 2

Stage 3

Marmul

GCC Countries

Other Ideas: PDO Water balance and distribution

PDO Water balance by area

LegendDisposal water ,000 m3/dxx

xx Injection make-up ,000 m3/d

xx Water for steam ,000 m3/d

Trans Oman Water Line (TOWL)

15

2007

20

2011

20xx Snapshot in year

Area21

62007 2011

2011

Area

Area

1815

2007

164

15

2007 2011

BahjaArea

Area 2011

824

20074

35

176247

2007 2011Area

CONCLUSION• PDO has taken several initiatives to eliminate disposal of PW into

shallow aquifers and thereby reduce environmental impact. • There is no unique solution to PW problem; optimal solution

depends on actual field conditions, like need for pressure support, water quality and local opportunities for re-use.

• Huge investment has gone to DWD to phase out Shallow Water Disposal and eliminate potential HSE risks.

• Technological initiatives have been deployed as alternative to DWD:– Reduce methods, like DHOWS and WSO, achieve pressure

support & debottlenecking– When PW serves no other purpose opportunities for re-use

emerge particularly when water salinity is low.

BACK UP SLIDES

NM-411 Well Casing and Completion Design

9 5/8" Csg. Shoe at 1322.3 mbdf

7” Kill string Surface - 44.53 m

Base Nahr Umr at 913- 930.8mAH

13 3/8" CSG

9 5/8" Csg.

Mahwis

Shammer(741.83m)

Perforations at :1200 - 1300 m

9 5/8" Csg. Shoe at 1322.3 mbdf

7” Kill string Surface - 44.53 m

Base Nahr Umr at 913- 930.8mAH

13 3/8" CSG

9 5/8" Csg.

Mahwis

Shammer(741.83m)

Perforations at :1200 - 1300 m