Strategies for Monitoring a Large Volume Commercial Injection –

a Hypothesis and a Test Program Susan Hovorka, Ramón Treviño, Tip Meckel

Gulf Coast Carbon Center, Bureau of Economic Geology, Jackson School of

Geosciences, The University of Texas at Austin

Presented to 7th Annual Conference of Carbon Capture and Sequestration sponsored by NETL, May -5-8, 2008 Pittsburg, PA

Gulf Coast Carbon Center (GCCC)

GCCC Research Team:Susan Hovorka, Tip Meckel, J. P. Nicot, Ramon

Trevino, Jeff Paine, Becky Smyth;Post-doc and students

Associate Director Ian DuncanDirector Scott Tinker

Newest member:Sempra

GCCC Field Tests for Monitoring and Verification Technologies - DOE-NETL and Industry Hosts

SECARB Phase II&II DenburyCranfield

Frio Test SiteTexas American Resources

SACROCSouthwestPartnershipKinderMorganNM Tech

Monitoring Schemes: Monitoring in Mature Commercial Context

• Benson study showed cost of a monitoring scheme, basic or enhanced, is a small fraction of the cost of the whole project.

• Should a large injection then have a large monitoring program?

A balanced and phased approach to permitting and monitoring

Not too restrictive: encourage early entry into CCS – gain experience;

Learn by doing

Adequate rigor to assure that early programs do not fail

Standardized, parsimonious

Early (now)

Mature (As defined by time? Or byinjection volume?)

Adequately rigorousto assure performanceand public acceptance

Phased Balanced

Current Monitoring Approaches Are Not Mature

Engineered Systems

MIT, positive annular

pressurex ? ? ? x ? ? no no x x

Character-ization

3-D seismic x x x   no x x x x no no

Wireline logs x no x x x ? x x x x x

Fluid and rock chemistry x no x ? x x x x x x x

Hydrology/production

historyx  no x x x ? x x x x x

other x           x        

Stress conditions x           x     x x

Plume Monitoring

4-D seismic x x x x no x x x x no no

borehole geophysics x no no no x no x x no no no

wireline logs  x no no no x no x x x no no

Fluid chemistry x no x ? x ? x no no no no

in-zone pressure  x no no no x no   x ? no no

above zone pressure x           no x    no no

Stress conditions x           ?   x no   no no 

Surface - air, soil, water x no x x x x x x x no no

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Need for Parsimonious Monitoring Program in a Mature Industry

• Standardized, dependable, durable instrumentation• Reportable measurements• Possibility of above-background detection:

– Need for a follow-up testing program– Hierarchical approach

:Parameter A

Within acceptable limits:continue

Parameter BNot withinacceptable limits:test

Within acceptable limits:continue

Stop & mitigateNot withinacceptable limits:

Two Areas of Concern in Area of Review

Injection well

Plume of injected CO2

Footprint of area over CO2

Footprint of area of elevated pressure

Most workers in CCS are most concerned about area (1).

Most UIC is concerned about area 1 +2

1

2

Risk is different in different parts of the AOR, and changes with time

Injection well

Footprint of area over CO2

Footprint of area of elevated pressure

Leakage risk is forbrine into USDW or to surface water

Leakage risk is forCO2 into the atmosphere, also possibility for damage to biosphere, to USDW or surface water

The relative size of both parts of the area of review is sensitive to

geologic characterization

12

12

A

B

Case A has a pressure sealessentially no fluid flow under possible pressure contrasts.The area of pressure elevation is large relative to area of CO2 foot print

Case B has a capillary entry sealvertical hydraulic conductivity contrast allows brine movement however CO2 cannot cross the seal.The area of pressure elevation is smaller relative to area of CO2

foot print.

Complex!

Complex!

Parsimonious Monitoring Hypothesis• Atmosphere

– Ultimate receptor but dynamic• Biosphere

– Assurance of no damage but dynamic• Soil and Vadose Zone

– Integrator but dynamic• Aquifer and USDW

– Integrator, slightly isolated from ecological effects

• Above injection monitoring zone– First indicator, monitor small signals,

stable. • In injection zone - plume

– Oil-field type technologies. Will not identify small leaks

• In injection zone - outside plume– Assure lateral migration of CO2 and

brine is acceptable

Aquifer and USDW

AtmosphereBiosphere

Vadose zone & soil

Seal

Seal

Monitoring Zone

CO2 plume

New proposal - monitoring box

Case example 1 - Dipping saline formation

Large volume injection plan

Upper Seal – Salado-TansillLower Seal – Seven Rivers

Monitoring zone - Yates

Delaware Mountain GroupThick section of fine sandstoneand organic-rich siltstones

Array of injection wellswith horizontal completions

Large volume monitoring plan – the box

Dip

Major fracture orientation

Horizontal injectorsand CO2 plumes

Monitoring wells of the ‘box” sides

Above zone array

Area of elevatedpressure

Test Plan

• Correctness of assumptions• Viablity in the field• Test site at Cranfield

Monitoring Plan

Injection

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Pressureat injector

Far-field pressure

Saturationat injectors

Saturation loggingprogram at injectors

Monitoring Plan – finds unacceptable response

Injection

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Pressureat injector

Far-field pressure

Saturationat injectors

Saturation loggingprogram at injectors

Reservoir not arealyExtensive?

Pressure muchLower than expected=a leak?

Low saturation=Poor sweep efficiency= large CO2 plume

Far-field pressure muchHigher than expectedAsymmetrical pressure plume

Cranfield as Case Study

• Reservoir produced to depletion1945-1965, all wells plugged and abandoned.

• Water invasion, pressure recovery 40 years• Brine is mobile phase, pressure hydrostatic• Dense data, wells reentered as access points.• Down-dip injection – pressure support to prevent

oil escape downdip.• Produced by gas lift after CO2 breakthrough• No water injection

Cranfield Unit setting

Cranfield unit boundary

Oil ring

Gas cap

Sonat CO2 pipeline

Denburyearly injectors

Denbury later Injectors shown schematically

Saline aquiferwithin Cranfield unit

SECARB (early) Phase II-III Field test

Phase II study areaDedicated observationwell pattern of logging in producers

Phase III study areaTwo observationwells, monitoring andlimited logging in producers

Phase II Research Focuses

(1) Sweep efficiency – how effectively are pore volumes contacted by CO2?– Important in recovery efficiency in EOR– For storage – what is capacity of subsurface? Prediction of

plume size(2) Injection volume is sum of fluid displacement, dilatancy,

dissolution, and rock+fluid compression– Bottom hole pressure mapping to estimate fluid displacement

(3) Effectiveness of Mississippi well completions regulations in retaining CO2 in GHG context– Above zone monitoring

Phase III Research Focuses

(1) Sweep efficiency – how effectively are pore volumes contacted by CO2?– High injection rates in brine – How much CO2 is dissolved? Compare brine to EOR– Cross-well program to assess sweep at high injection rates

(2) Injection volume is sum of fluid displacement, dilatancy, dissolution, and rock+fluid compression– Tilt to start to understand magnitude of dilatancy– Bottom hole pressure mapping to estimate fluid displacement– Real-time cross-well program to map plume –pressure

relationships(3) Surface test plan – assess the effectiveness of surface

monitoring in an area of deep water table

Two areas need monitoring: buoyant CO2 and elevated pressure in brine

CO2 plumeElevated pressure

CO2 injection (no production) pressure plume extends beyond the CO2 injection area

In EOR CO2 injection is approximately balanced by oil, CO2, and brine production no pressure plume beyond the CO2 injection area

Elevated pressure

5 10 15

resOhm-m

-150-100 -50 09,700

9,800

9,900

10,000

10,100

10,200

10,300

spmV

DEP

TH (f

t)10-3/4" casing set @ 1,825'

16" casing set @ 222'

13-Chrome Isolation packer w/ feed through13-Chrome Selective seat nipple

Side Pocket Mandrel w/dummy gas valvePressure transducer1/4" tubing installed between packers toProvide a conduit between isolation packers

13-Chrome Production packer w/ feed thrus

Tuscaloosaperforation

7" casing set @ 10,305'

Monitoring Zone

CO2 Injection Zone

Side Pocket Mandrel w/dummy gas valvePressure transducer

Test adequacy of Mississippi well completions for CO2 sequestration

Con

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Phase II Area

Phase III Early Test:Brine interval

The area selected for the Phase III Early Test is immediately north of the SECARB Phase II “Stacked Storage” study underway, within unitized field.

Brine

ResidualOil

ResidualGas

Inj+Mon

Phase II Study area

InjOilProd

Monitoring

Inj +Mon

Proposed Phase IIIEarly study area

Inj +Mon

Inj+Mon

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Documented

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Cranfield Program OverviewCranfield Program Overview

Hypothesis: Parsimonious Monitoring Program in a Mature

Industry• Standardized, dependable, durable

instrumentation, reportable measurements• Frequent pressure measurements above-zone

and in-zone – documents conformance• Episodic saturation logging (at injectors?) syn-

and post-injection documents sweep.• Trigger points:

– an unexpected measurement initiates a pre-planned research type monitoring program to assess origin of response.

Parameter A

Within acceptable limits:continue

Parameter BNot withinacceptable limitstest

Stop & mitigateNot withinacceptable limits:

PHASE II OBSERVATION WELL LOCATION

3 MMCFD Injection ratesPhase II : ½ Million Tons/yrPhase III : 1-1.5 Mt/yr

Marine ShaleSeal

Injection Sand

Monitor Sand

375’

Geologic Sequestrationof Carbon – Put it back

Carbon extractedfrom coal or otherfossil fuel…

Returned into the earthwhere it came from

www.gulfcoastcarbon.org