lawrence livermore national laboratory · lawrence livermore national laboratory under contract...

Lawrence Livermore National Laboratory

SECARBCranfield Electric Resistance Tomography

(ERT) Observations

C. Carrigan (LLNL)

( )(1 Dec 2009 – 1 Mar 2010)

C Ca ga ( )D. La Brecque (MPT)D. Larsen (Promore-Corelab) A. Ramirez (LLNL) W D il (MPT) W. Daily (MPT) D. Freeman (Sandia Tech.)J. Friedmann (LLNL) S. Hovorka (BEG – UT)( )

Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, CA 94551This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

(photos courtesy of David Freeman)

“ERT 101-- add history”ERT 101 add historyInitial development for geophysical use (1980’s)

I

geophysical use (1980 s) --US, Japan, CanadaSwitched DC, 4 electrode

E Ei

measurement approachMeasurements provide E and I pairs for many

E E

ResistivityE and I pairs for many electrode combinations and current pathwaysEl t i l d t i t d t

Anomaly

Electrical data inverted to find resistivity model that best fits E and I data subject ERTERT

I

to imposed constraints DASDAS

2Q1143


Inversion

Advantages of ERT Imaging ApproachAdvantages of ERT Imaging Approach

• Robust System – no moving parts

• Outside‐the‐casing installation

• Robust System – no moving parts

• Outside‐the‐casing installationg

• Relatively low cost to install

• Very low cost for continuous, autonomous

g

• Relatively low cost to install

• Very low cost for continuous, autonomous yoperation

• Can be operated remotely with internet t l

yoperation

• Can be operated remotely with internet t lcontrolcontrol

3Q1143


Cranfield ERT ArrayCranfield ERT Array

World’s deepest ERT arrays (~10,500 ft, 3200 m)Two vertical cross-well electrode arrays ~130 ft (~41 m) apartAll components mounted external to casing21 electrodes (14 and 7 arrangement)220 000 ft (~67 km) of insulated wiring220,000 ft ( 67 km) of insulated wiring35,000 ft (~10.7 km) of cable armoringFull remote internet operation using M lti Ph T h l d t i itiMulti-Phase Technol. data acquisition system (DAS-1)4 different electrode sampling schedules~10,000 measurements/day

4Q1143


Cross-Well ERT In The Lower Tuscaloosa Formation (>104 ft)Cross-Well ERT In The Lower Tuscaloosa Formation (>10 ft)

Obs #1/Obs #2Scaled Dimensions

F2 F3

~10,500 ft

~3.2 km

200 ft61 m

140 ft~43 m

5Q1143


Basic data acquisition system – autonomous, 24/7 operation q y , p

6Q1143


ERT Array Construction: ElectrodesERT Array Construction: Electrodes

Electrode collars are 316-Electrode collars are 316L stainlessCollars mount on fiberglass-reinforced well casingFilled-resin centralizers protect electrodes & cablescablesIn use for 8 months

7Q1143


ERT Array Construction: Individual Elect. CablesERT Array Construction: Individual Elect. Cables

#16 AWG TEC cables attach to individual electrodeselectrodesEncapsulated in stainless tubing and polypropylenetubing and polypropylene TEC cables attach to “splitter” via insulatedsplitter via insulated Swagelock connectors

8Q1143


ERT Array Construction: Cable “Splitter”ERT Array Construction: Cable Splitter

7 connectors attach cables7 connectors attach cables to bottom of splitterSingle connector off top g pfeeds into double-armored 7-conductor wireline cableWireline cable terminates at surface

9Q1143


Synthetic Model Study Multi Phase Technologies LLCSynthetic Model StudyLayered background created by simple averaging of

Multi-Phase Technologies, LLC

well logs

Introduced 100 Ohm m anomaly from 2180 to 3210 mIntroduced 100 Ohm-m anomaly from 2180 to 3210 m depth

Anomalies centered on injector and extend +/- 75m, 100m and 125 m from injector

Boreholes used for imaging are 69 m and 112 m from injector

Data inverted using robust inversion, assumed 3% noise

10Q1143


noise.

Model of CO2 anomaly invading the reservoir

X X X

oosa

X

XX

X

XX

X

XX

Tusc

alo X

X

X

X

X

X

XX

XX

XX

11Q1143


ERT reconstructions of synthetic CO2 model, percent resistivity changeresistivity change

X X X

oosa

X

XX

X

XX

X

XX

Tusc

alo X

X

X

X

X

X

XX

XX

XX

12Q1143


Modeling study conclusionsModeling study conclusions

The imaging routine tends to expand the size of the anomalous zone by 1 voxel width.

The coarse resolution of these images is due primarilyThe coarse resolution of these images is due primarily to the relatively few electrodes available.

Some images show fairly strong “overshoot effects” shown as blue colored zones above and below the anomaliesanomalies

Some artifacts below the bottom of the Tuscaloosa

The good news is that despite these issues it should be possible to follow the approximate progress of the CO2

13Q1143


possible to follow the approximate progress of the CO2.

Nulled Background At Initiation Of Injection(1 Dec 2009)(1 Dec 2009)

x

x

Direction of x

x

x

CO2 plume x

x

x

Injectorx

14Q1143


Multi-Phase Technologies, LLC

Injector Overworking Fluids?(4 Dec 2009)(4 Dec 2009)

x

x

Direction of CO plume

x

x

xCO2 plume x

x

xInjector

x

15Q1143


Arrival of CO2 Plume?(9 Dec 2009)(9 Dec 2009)

X

X


X

X

XCO2 plume X

XX

InjectorCO2 arrival?

X

16Q1143


Growth Of CO2 Plume?(21 Dec 2009)(21 Dec 2009)

X

X


X

X

XCO2 plume X

X

XInjector

X

17Q1143


Growth Of CO2 Plume?(11 Jan 2010)(11 Jan 2010)

X

X


XX

XCO2 plume

X

X

X

InjectorX

18Q1143


Growth Of CO2 Plume?(13 Jan 2010)(13 Jan 2010)

x

x


x

x

xCO2 plume x

x

x

Injectorx

19Q1143


Growth Of CO2 Plume?(5 Feb 2010)(5 Feb 2010)

x

x


x

x

xCO2 plume x

x

x

Injectorx

20Q1143


Growth Of CO2 Plume?(23 Feb 2010)(23 Feb 2010)

x

x


x

x

xCO2 plume x

x

x

Injectorx

21Q1143


Current Conclusions / InterpretationsCurrent Conclusions / Interpretations

CO2 produces strong signal CO2 p oduces st o g s g aERT reconstructs basic plume details

Coarse resolutionCoarse resolutionResistive anomaly appears associated with CO2movement in Lower Tuscaloosa formation with Dec 9 arrival at F2Significant positioning and resolution loss due to electrode damage in F2, analysis continuesConductive anomaly apparently due to work over fluids appears just after start of injectionSystem continues to remotely log ~10,000 ERT

t /d (M 2010)

22Q1143


measurements/day (May 2010)

Lessons learnedLessons learned

Robustness of electrode centralizers need improvementimprovementTime required for cabling installation needs to be shortened while maintaining array robustnessg y

Choice of electrical connectors may be very important

May need more well centralizers to protect wiring and electrodes

23Q1143


Thank youThank you

Any questions ?

I brought electronic/hard copies of publications:Ramirez A R Newmark and W Daily 2003 Monitoring carbon Ramirez, A., R. Newmark, and W. Daily, 2003, Monitoring carbon

dioxide floods using electrical resistance tomography (ERT): Sensitivity studies, Journal of Enviromental. and Eng. Geophysics ,vol. 8 no 3 pp 187 - 2088, no. 3, pp. 187 208.

Daily, W., A. Ramirez, A. Binley and D. LaBrecque, 2005, Electrical Resistance Tomography--Practice and Theory, Soc. Exploration Geophysics: Near Surface Geophysics ed Dwaine Butler Geophysics: Near Surface Geophysics, ed. Dwaine Butler

24Q1143


SECARB Cranfield ERT SiteSECARB Cranfield ERT Site

Injector

F2F3 F114 electrode7 electrode

227 feet @ bottom

69 m

140 feet @ bottom

43 m

Equipment Shed – ERT Data Acquisition System

25Q1143


Cranfield Phase III Study AreaCranfield Phase III Study Area

26Q1143


lawrence livermore national laboratory · lawrence livermore national laboratory under contract...

Documents