ConocoPhillips test results and data analysis

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ConocoPhillips test results and data analysis

Brian J. Anderson Associate Professor, Chemical Engineering, West Virginia University

Methane Hydrate Advisory Committee Meeting, Thursday, June 06, 2013

• North Slope reservoir‐scale field trial to evaluate CO2/CH4 exchange

• Short‐term test to demonstrate concepts at larger‐than‐lab scale

• Validate exchange mechanism results from laboratory work – Confirm injectivity into naturally occurring methane

hydrates

– Confirm methane release without production of water or sand

– Obtain reaction rate data to facilitate reservoir‐scale modeling

• Demonstrate stable production of natural gas hydrates by depressurization

Overall Iġnik Sikumi Project Goals

• 2008 – 2010 – Select site and gain access – Characterize reservoir

• 2011 – Drill, log, complete and suspend Iġnik Sikumi #1 – Design field test

• 2012 – Re-enter well and perforate – Perform exchange test – Perform depressurization test – P & A well and remediate site – Prepare datasets – Begin data analysis

• 2013 – Data analysis and history matching

Project History

• Data Correction/Reconsolidation in Progress – Outliers/spikes removed – Time stamps for each source corrected – GC data reprocessed – Three DTS data sets obtained

• Un‐normalized and 2 types of normalization

– Created 1 and 5 min time average datasets – Adding corrections for dead volumes/wellbore storage

• Path Forward – Perform material balance of test – Injectivity analysis, using simulation

• Infer hydrate saturation changes

– Production analysis using cell‐to‐cell model • Gas phase composition history match

– Issue final database and report – DOE workshop

July 2012 Status

Capillary-bound water

Clay-bound water

Movable water

39% Φavg

“C” Sand

25% SWavg

41% movable

Tem

per

atu

re

Tem

per

atu

re c

han

ge si

nce

6F

eb2

01

2

Initial Period before any well work Temperature linear with geothermal gradient (~1.79oF/100ft), Temperature change ~0

Injection

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

Days since 6 Feb 2012

100

75

50

25

Rat

e (m

scf/

d)

PerforationInjection started

Injection endedWell shut in

1700

1300

1500

1600

1400

BH

Pre

ssu

re p

sia)

Overall Production – Gas rates, Pressure, and Temperature

Ignik Sikumi #1 Production

Flowback - Production Period #1

Days since 6 Feb 2012

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

100

50

Rat

e (m

scf/

d)

700

900

1000

800

BH

Pre

ssu

re p

sia)

600

1100150

Well openedUnassisted flow

Well shut-inJet pump installed

Well shut-inReplace sep. valve

Well shut-inFlare line freeze

Well shut-inReplace jet pump

Well shut-inReplace sep. valve

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2T

emp

erat

ure

ch

ange

sin

ce 6

Feb

20

12

Days since 6 Feb 2012

50

25

Rat

e (m

scf/

d)

Well openedJet pump #2

Shut-inGlycol injected below jet pump End of production procedure started

800

300

400

600

700

500

BH

Pre

ssu

re p

sia)

Flowback - Production Period #2

Successful injection of CO2 mixture into hydrate reservoir

Methane produced both above / below CH4-stability

pressure CO2 was retained in the reservoir compared with N2

Indicates the possibility of CO2 exchange

Depressurization sustained below CH4-stability pressure Steady increase in production rate Over 850 mscf (24,000 scm) of CH4 produced in total Low BHP achieved (~250 psi)

Solids production significant

Evidence for heterogeneous injection / production

Summary Observations

12

• Diagrams of the operations included – PI&D’s + dead volumes of surface equipment and well

• Master Variable List – Where to go for complete info on any recorded variable

• e.g., what instrument recorded the data, calibration, etc

• Supporting Data Document – Where to go for notes on calculations and data corrections

• Operation Event Log – Where to go to see what was happening at every step of the

test

• All raw data in MySQL and CSV format

• All final data available in MS SQL database format, CSV, Matlab – Clean, 1 min averaged, and 5 min averaged data

Database Summary

13

Data Streams

• Composition

– On-line GC (~15 min sampling int.)

• Continuous downhole conditions

– 3 downhole pressure gauges (P&T)

– Distributed Temperature Sensing (T per ft)

• Continuous surface conditions

– Pump rates

– Flow rates (gas, jet pump fluid)

– Line pressures and temperatures

– Separator P&T

• Produced fluid measurements

– Collected on regular intervals

– Water prod rate

• Tank straps (~30min int.)

– Water (~1hr int.)

• pH, salinity, SG

– Gas (~1hr int.)

• Gas gravity

Database Folder

15

• Adiabatic CTC Model (ConocoPhillips)

– Cell Volume (3.5 ft), SH = 65%, Pi = 1000 psi, Ti = 40.5 F

• Solids production

• Heterogeneous production

• History-match simulations of the Iġnik Sikumi field test with newly-developed Mix3HRS software

• Complex pressure, temperature, and composition history

– CO2+N2 injected into a CH4 reservoir with all 3 gases produced

– Competing thermodynamics for hydrate formation and dissociation in the reservoir

Modeling and Simulation Efforts

Hydrate

Saturation

Hall Plot – Varying Permeability

17

Hall Plot

0

1000

2000

3000

4000

5000

0 25 50 75 100 125 150 175 200 225

Cumulative injection (MSCF)

Su

m(d

P*d

t)

Hydrate pilot Gas injection model with k variation

Hall Plot

0

1000

2000

3000

4000

0 25 50 75 100 125 150 175 200

Cumulative injection (MSCF)

Su

m(d

P*d

t)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

In-s

itu

pe

rm (

mD

)

Gas Injectivity Estimated in-situ perm

Hall Plot

0

1000

2000

3000

4000

0 25 50 75 100 125 150 175 200

Cumulative injection (MSCF)

Su

m(d

P*d

t)

0.650

0.700

0.750

0.800

0.850

Hy

dra

te s

atu

rati

on

Gas Injectivity Estimated average Sh

A.

B.

Permeability adjusted over time

One possibility is Δ hydrate sat.

Good match obtained

• The Injection flow rate and cumulative injection of CO2 and N2 into the

reservoir are matched with the field data.

Injection matching

Post-Injection Period

Tem

per

atu

re c

han

ge si

nce

6F

eb2

01

2

Days since 6 Feb 2012

BH

Pre

ssu

re p

sia)

1340

1220

1300

1260

Post-Injection Period

Production

0

200

400

600

800

1000

1200

1400

0

200

400

600

800

1000

1200

1400

4-Mar 8-Mar 12-Mar 16-Mar 20-Mar 24-Mar 28-Mar 1-Apr 5-Apr 9-Apr

Cu

mu

lati

ve P

rod

uce

d G

as (m

scf)

an

d W

ate

r (b

bl)

Do

wn

ho

le P

ress

ure

(p

sia)

Unassisted Flowback

4-Mar 14:00 – 6-Mar 00:00

Jet-Pump Flowback #1

7-Mar 04:00 – 13-Mar 23:30

Jet-Pump Flowback #2

15-Mar 18:52 – 18-Mar 10:40

Jet-Pump Flowback #3

23-Mar 06:20 – 11-Apr 00:00

CH4 Hydrate Stability P

(based on downhole T)

0

200

400

600

800

1000

1200

1400

0

200

400

600

800

1000

1200

1400

4-Mar 8-Mar 12-Mar 16-Mar 20-Mar 24-Mar 28-Mar 1-Apr 5-Apr 9-Apr

Cu

mu

lati

ve P

rod

uce

d G

as (m

scf)

an

d W

ate

r (b

bl)

Do

wn

ho

le P

ress

ure

(p

sia)

Unassisted Flowback

4-Mar 14:00 – 6-Mar 00:00

Jet-Pump Flowback #1

7-Mar 04:00 – 13-Mar 23:30

Jet-Pump Flowback #2

15-Mar 18:52 – 18-Mar 10:40

Jet-Pump Flowback #3

23-Mar 06:20 – 11-Apr 00:00

CH4 Hydrate Stability P

(based on downhole T)

First 200 mscf produced above CH4 Hydrate stability conditions

Cumulative Gas

Cumulative

Water

More CH4 produced than Equilibrium Model predicts.

CH4 composition in produced gas

0

20

40

60

80

100

0 100 200 300 400 500 600 700 800 900

Cumulative produced gas (MSCF)

CH

4 c

om

po

sit

ion

Pilot 3.5 ft tank

Model predicts exchange significantly depletes CH4 from the near well region.

Pi = 1000 psia Shi = 65 % Ti = 40.5 F

% Recovered based on Injected Amounts

23

0

10

20

30

40

50

60

70

80

90

100

4-Mar 9-Mar 14-Mar 19-Mar 24-Mar 29-Mar 3-Apr 8-Apr 13-Apr

% R

eco

vere

d

N2

CO2

Observations: Field versus Model

• Not enough CH4 from model • Not enough water from

model • Temperature increase too

high in model • Recovery of N2 to CO2

reversed in model • Examining potential

mechanisms of gas production

1. Dissociation in place w/o permeability enhancement

2. Dissociation in place w/sand migration + permeability enhancement

3. Production of solid hydrate (< 200 μm) and subsequent dissociation in wellbore above the jetpump when contacted with warm power fluid

N2 and CO2 recovery

0

20

40

60

80

100

0 100 200 300 400 500 600 700 800 900

Cumulative produced gas (MSCF)

N2

an

d C

O2

re

co

ve

ry f

ac

tor

N2_recovery CO2_recovery

Sand Production

25

0

10

20

30

40

50

60

70

5-Mar 10-Mar 15-Mar 20-Mar 25-Mar 30-Mar 4-Apr 9-Apr

Esti

mat

ed

San

d P

rod

uct

ion

(bb

l)

Jet-Pump Flowback #1

7-Mar 04:00 – 13-Mar 23:30

Jet-Pump Flowback #2

15-Mar 18:52 – 18-Mar 10:40

Jet-Pump Flowback #3

23-Mar 06:20 – 11-Apr 00:00

From: Kurihara, et al., Proceedings of the 7th International Conference on Gas Hydrates (ICGH 2011), Edinburgh, Scotland,

United Kingdom, July 17-21, 2011

Figure 17 Schemata of reservoir performances through 2007 and 2008 tests inferred from history matching simulation

Mechanism 2 – Experience at Mallik

Mechanism 2

From: Kurihara, et al., Proceedings of the 7th International Conference on Gas Hydrates (ICGH 2011),

Edinburgh, Scotland, United Kingdom, July 17-21, 2011

Figure 11 Concept expressing overall grid block permeability as a function of MH saturation with

growth of high permeability conduits

Mechanism 3: Solid CH4 – Hydrate produced?

CH4 Hydrate - CO2(l)

contact

Local

disassociation of

CH4 Hydrate

Reformation of

mixed CO2-CH4

Hydrate

CH4 Hydrate - CO2(l)

contact

Local

disassociation of

CH4 Hydrate

Reformation of

mixed CO2-CH4

Hydrate CH4 Hydrate - CO2(l)

contact

Local

disassociation of

CH4 Hydrate

Reformation of

mixed CO2-CH4

Hydrate

CH4 Hydrate - CO2(l)

contact

Local

disassociation of

CH4 Hydrate

Reformation of

mixed CO2-CH4

Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

Native State Exchange Depressurization

Well Screen

Largest source of CH4 & water = CH4 Hydrate

Solids (sand) were produced

Mechanism 3: CTC Model Solids Recombination – CH4 Match

CH4 composition in produced gas

0

20

40

60

80

100

0 100 200 300 400 500 600 700 800 900

Cumulative produced gas (MSCF)

CH

4 c

om

po

sit

ion

Field data Hypothesis

Mechanism 3: CTC Model Solids Recombination – Recovery

CO2 and N2 recovery factor

0

20

40

60

80

100

0 100 200 300 400 500 600 700 800 900

Cumulative produced gas (MSCF)

CO

2 a

nd

N2

re

co

ve

ry f

ac

tor

N2 CO2

Mechanism 3 • Method

– Use EXPRO water rate and %Sed measurements

– Scale sediment rates to match observed cumulative sand production

• Worst-case Assumptions

– All sand produced had associated CH4 hydrate that was produced

– SH values from CMR log

• Gives upper limit to CH4 from solids

0

50

100

150

200

250

300

350

400

450

500

550

0 100 200 300 400 500 600

Cu

m. C

H4

gas

pro

du

ced

(m

scf)

Time (Hours since 3/4/2012 14:00)

Measured Cumulative CH₄ Production (mcf)

Max Cumulative CH₄ Prod by solids

0

4

8

% S

edim

ent

0

500

1000

1500

2000

Wat

er R

ate

(bb

l/d

ay)

• Mechanism 2

– Dissociation in place w/sand migration + permeability enhancement

• Mechanism 3

– Production of solid hydrate (< 200 μm) and subsequent dissociation in wellbore above the jetpump when contacted with warm power fluid

• Reservoir heterogeneity

Field trial likely a combination of mechanisms

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

CH4 Hydrate - CO

2(l) contactLocal disassociation of CH

4 Hydrate

Reformation of mixed CO2-CH

4Hydrate

Well

Tracer … Argument for Heterogeneity?

0

10

20

30

40

50

60

70

80

90

4-Mar 9-Mar 14-Mar 19-Mar 24-Mar 29-Mar 3-Apr 8-Apr 13-Apr

% T

race

r R

eco

very

R114

SF6

Jet-Pump Flowback #1

7-Mar 04:00 – 13-Mar 23:30

Jet-Pump Flowback #2

15-Mar 18:52 – 18-Mar 10:40

Jet-Pump Flowback #3

23-Mar 06:20 – 11-Apr 00:00

Unassisted Flowback

4-Mar 14:00 – 6-Mar 00:00

0

10

20

30

40

50

60

70

80

90

4-Mar 9-Mar 14-Mar 19-Mar 24-Mar 29-Mar 3-Apr 8-Apr 13-Apr

% T

race

r R

eco

very

R114

SF6

Jet-Pump Flowback #1

7-Mar 04:00 – 13-Mar 23:30

Jet-Pump Flowback #2

15-Mar 18:52 – 18-Mar 10:40

Jet-Pump Flowback #3

23-Mar 06:20 – 11-Apr 00:00

Unassisted Flowback

4-Mar 14:00 – 6-Mar 00:00

Heterogeneous Injection / Production

SH = High

SH = Low

SF6

SF6 R114 Inject SF6 / R114

SF6

SF6 R114

Produce

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

Days since 6 Feb 2012

100

75

50

25

Rat

e (m

scf/

d)

PerforationInjection started

1700

1300

1500

1600

1400

BH

Pre

ssu

re p

sia)

0.0 0.2 0.4 0.6 0.8 1.0

Saturation (v/v)

CMR Free FluidBound FluidNPORHydrate Saturation

Heterogeneous Injection

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

Days since 6 Feb 2012

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

150

100

50Rat

e (m

scf/

d)

1100

700

900

1000

800

BH

Pre

ssu

re p

sia)

600

Flowback - Production Period #1

0.0 0.5 1.0Hydrate Saturation

Days since 6 Feb 2012

Tem

per

atu

re c

han

ge si

nce

6F

eb2

01

2

2,240

2,245

2,250

2,255

2,260

2,265

2,270

2,275

0 2 4 6 8

de

pth

(ft

)

Temperature (°C)

T(°C) 6.1hrs

T(°C) 18.7hrs

T(°C) 33.6hrs pre-shutin

T(°C) 61.7hrs end-shutin

T(°C) 100hrs end_of_sim

Production Period #1

Production Simulations Production

− Production phase is modeled by maintaining fixed-state boundary as

aqueous phase at the bottom-hole pressure.

− Still attempting to match sand production and each gas rate (with recovery

factors)

• Demonstrated injection of CO2 mixture into water filled hydrate reservoir – Possibly some injection out-of-zone

• Confirmed mixture / CH4-Hydrate Exchange – CH4 produced above CH4-hydrate stability pressure

– Produced CO2 : N2 ratios altered from injectant value

– Injectivity decline consistent w hydrate exchange

• Low BHP are achievable during depressurization – Icing not observed @ 250 psi BHP

• Heterogeneous injection / production observed (DTS)

• Temperature record consistent w hydrate association / dissociation during injection / production cycles

Tentative Conclusions

39

• Datasets and ConocoPhillips project reports can be downloaded from the NETL website.

– http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/rd-program/ANSWell/co2_ch4exchange.html

– google “ignik sikumi” or see the announcement in the latest Fire in the Ice

• Organizing a problem for the Code Comparison Project on the Ignik Sikumi Results

• DOE has previously facilitated creation of Special Volumes in peer-reviewed journals to consolidate reporting

Going Forward

Questions?

Backup Slides – do not print

CPAI - Iġnik Sikumi #1 and PBU L-pad

“E sand:” 31ft hydrate

Sagavanirktok “F Sand:” Ice-filled

Target: Upper C Sand

base permafrost

“D sand:” 49ft hydrate

“C sand:” 67ft hydrate

Iġnik Sikumi #1

Wellbore Construction

Upper Completion

Lower Completion

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

Days since 6 Feb 2012

Tem

per

atu

re c

han

gesi

nce

6F

eb2

01

2

150

100

50Rat

e (m

scf/

d)

1100

700

900

1000

800

BH

Pre

ssu

re p

sia)

600

Flowback - Production Period #1

− Two data files are incorporated into

Teq = f(P,y1,y2) and Peq = f(T,y1,y2)

where T is temperature ( C), P is

pressure (MPa), y1 is CH4 composition

in gas phase and y2 is CO2 composition

in gas phase (yN2 is not independent)

• Two new primary variables for each phase

state and two governing equations are added

for the binary (CO2) and ternary (N2) gases

• Gas-Hydrate (GsH) system was added to

consider the possibility of converting all

available free water to form hydrate with

injected gas

• The phase equilibrium data for a three-component (CH4-CO2-N2) gas hydrate are incorporated

using tri-linear interpolation, where in the code can interpolate data from a table containing

stability pressure, temperature and composition of the hydrate phase

– Based on predictions using our statistical mechanics model that has been validated against

experimental data for 1-, 2-, and 3-component gas mixtures with low error

Prediction of stability pressure for the CH4-CO2 mixed hydrate

system

Ternary Hydrate Modeling

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