©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Monitoring and Risk ManagementMonitoring and Risk Management
Maurice Dusseault
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Why Monitor?Why Monitor?
To increase efficiency of oil production To make intelligent workover decisions Process control enhancement (higher recovery) Well rate enhancement, field management
To improve our understanding of the physics To test model predictions To provide verification of scaling approaches
between lab, theory, and the field For safety& environmental purposes All of these reduce risk
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
The Optimization LoopThe Optimization Loop
DESIGN
MONITOR PRODUCE
In situ state (p,s…Science studiesBehavioral laws
SimulationsExperience
OPTIMIZATION
Process Control
Better physicsBetter models
PredictionsOther applications
New processes
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Classification of Approaches…Classification of Approaches…
Proximal methods (in well, at the flow line…) Remote methods (generally geophysics) Passive methods (e.g. T, p, MS emissions) Active methods (4D seismic, electrical surveys) Snapshot methods (e.g. an InSAR image) Continuous methods (e.g. electronic tiltmeters) Offshore/onshore (e.g. seafloor pressure gauges
offshore, vs. survey points onshore)
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
““Special Well” MonitoringSpecial Well” Monitoring
7” casing, cemented to surface
Optimization of pump based on production rate, downhole pressure, and pump torque
Rods to drive pump
PC Pump
Producing Stratum
Cable to surface
BHP transducer, in tubing, in annulus
Ports for vacuum sample bottles and bulk production samples
Densimeter, flow velocity
Annular oil level (acoustic device)
Foam?
Annular gas rates, pressures
Accelerometer
Behind-the-casingtransducers?
span span span
ref. ref.ref.
12.0 12.0 12.0
FrequencyAmplitude
5% of wells in a heavy oil field can be specially monitored
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Manual Volumetric AnalysisManual Volumetric Analysis
E.g.: Dean-Stark for oil and water content
Sand settling tubes for sand volume percent
To measure gas cut, the flow line is opened to a vacuum bomb, sealed, and sent for analysis
Clay % as well? Requires hand work!
vacuum flask% gas,& type
% sand
+ Dean-Stark foroil content and water percent
BS&W
Risk management requires measurements, and some of
them are made by hand…
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Sand Granulometry for SandingSand Granulometry for Sanding
Establish a type gran-ulometry from cores
Precise granulometry: bulk average samples
+Frequency of large grain occurrence
+Clay % (<2 or 5 m) Correlate to type data See where sand is
coming from… Other inferences…
0
5
10
15
20
25
30
-5 -3 -1 1 3
TypeCut
units
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Monitoring: Logging Cased WellsMonitoring: Logging Cased Wells
(log + casing collar locators (z) CNL + phase analysis to estimate porosity
changes behind casing Multi-arm caliper log to track casing shape Dipole sonic log to assess velocity and
attenuation state farther from the wellbore T logs and tracers behind the casing logs Borehole gravimeter log (half-space effect) Other useful logs? Saturation changes, acoustic
logs for microannulus, and so on…
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Measuring Reservoir ChangesMeasuring Reservoir Changes
Before CHOPS ~ 30% After: changes, k, …
Top cavity or gas zone Shaley streaks are gone Thin cemented beds too Yielded zone ~ 40% Lower zones less so
We can use logs to help understand CHOPS
Various logs, used at different times
0 10 20 30 40 50
shaleyzone
cementedsiltstone
shale baserock
before after
unaffected
shale“gone”
cavity or gas zone
~30% 36-44%
porosity
Neutron porosity log
shale caprock
Influence radius
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Remote Monitoring - GeophysicsRemote Monitoring - Geophysics
2-D VSP 3-D (4-D) seismic velocity, Quality tomography Cross-hole seismic tomography Surface and deep deformation measurements Microseismic monitoring of shearing events Electrical monitoring of {tomography Multipurpose monitor wells Gravimetry, others, but we can’t do all of them… …so let’s look at deformation measurements
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Temperature Changes & Temperature Changes & ΔΔV…V…
shale
cs.-gr. ss
ss
fn.-gr. ss
shale
Δp = 0
ΔT = 0
ΔT = 100ºC
conduction convection
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Temperature Changes…Temperature Changes…
Conductive-convective heat transport But, ΔT causes rock ΔV as well!
β = 3-D thermal expansion coefficient The ΔV acts against the surrounding rock This alters the effective stress… So what?? What does this mean??
TV
V
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Reservoir Volume ChangeReservoir Volume Change
Expandingregion
from +T
+ΔT generates expansion of the zone. This means that it “pushes” against the world, and radial stresses rise, tangential stresses drop.
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
A Pure Volume Change - A Pure Volume Change - ΔΔVV
Z
Surface deformation shapes
Δz]V
ΔVΔV
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
A Pure Shear Displacement - A Pure Shear Displacement - ΔΔSS
Z
Surface deformation shapes
ΔS
Δz]S
ΔS
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
ΔΔV + V + ΔΔS S DeformationsDeformations
Z
Surface deformation shapes
ΔV ΔS
Δz]V + Δz]S
ΔV ΔS
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Consequences: Shear DilationConsequences: Shear Dilation
hot regionexpansion
r
triaxial test analogy
ΔT→ΔV→Δσ′In weak rocks, shear
occurs. This is a process of dilation
+V
cool region
extensional
compressional r
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
So… What Happens Now?So… What Happens Now?
+ΔT causes +ΔV (expansion) +ΔV pushes against the rock → +Δσ′ However, the radial stress rises, the tangential
stress drops, and shear occurs This is a process of dilation. Dilation ΔV is ×5
to x10 times larger than ΔT effect Some consequences:
φ↑, k↑, all transport properties change Stresses change, fracture pressures (PF),… And so on…
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Dilation and Recompaction…Dilation and Recompaction…
time
Cycle 1 Cycle 2 Cycle 3 Cycle 4
inje
ctio
n
soa
kp
rod
uct
ion
inje
ctio
n
so
ak
pro
du
ctio
n
Limited recovery of z in first production cycles
1.00
0.75
0.50
0.25
inje
ctio
n
soa
kp
rod
uct
ion
0
Ve
rtic
al h
ea
ve –
z
- m
Almost full Δz recovery observed in later cycles
z
Cold Lake – 40 m thick zone
ΔV from ΔTinitial ground elevation
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Shear Dilation from Shear Dilation from ΔΔTT
Assume ΔT = +250ºC throughout zone… For a 40 m thick reservoir, Δz ≈ 6 - 9 cm Δz of 15-30 cm observed in a single cycle Also, after many cycles, a permanent Δz of 50-
80 cm has been observed! Clearly, most of this is shear dilation… How do you couple these processes? How do you quantify and calibrate? MONITORING AND ANALYSIS!!!
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Deformation Monitoring MethodsDeformation Monitoring Methods
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Deformation MonitoringDeformation Monitoring
Shear and V generate a deformation field This field can be sampled: z, (tilt) With enough quality data, inversion possible
An inversion is a calculation of what is happening at depth, based on remote measurements
Inversions give the magnitude and location of shearing and volume change
These factors are linked to inj./prod. history Reservoir management decisions, such as
inj./prod. strategy, based on interpretations
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Deformation Measurements…Deformation Measurements…
Some technologies… Satellites – INSAR Surface surveys Aerial photography Laser ranging Precision tiltmeters Extensometers Casing strain gauges Fibre optics methods Geophysical logging …
Time
6 hours
Pre
ssu
re o
r su
rfac
e ti
lt
pressure
Δtilt at
one point
“event”
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Radioactive BulletsRadioactive Bullets
Zone of interest selected Before casing, radioactive
bullets are fired into the strata (not too deep!)
Casing is placed Baseline gamma log run Logging is repeated (T),
and the difference in gamma peaks is measured
Strain = L/L, accuracy ~1-2 cm over a 10 m base
“stable” reference
L L-L
“baseline” log“repeat” log
L
com
pact
ing
zone
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Casing Collar LogsCasing Collar Logs
Casing moves with the cement and the rock The casing collar makes a thicker steel zone This can be detected accurately on a log
sensitive to the effect of steel (magnetic) Logs are run repeatedly, strain = L/L Similar to previous diagram Short casing joints can be used for detail If casing slips, results not reliable If doglegged, can’t run the log
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Borehole ExtensometersBorehole Extensometers
Wires anchored to casing Brought to surface, tensioned
(max 1000 m?) Attached to a transducer or to
a mechanical measuring tool Readings taken repeatedly Resistant to doglegging Logs can’t be run in the hole Other instruments can be
installed in the same hole
wire 1wire 3
wire 2
W
anchor 3
anchor 1
anchor 2
sheaves
casing
L
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Casing DeformationCasing Deformation
“Wedging” Shear
Courtesy Trent Kaiser, noetic Engineering
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Other Borehole MethodsOther Borehole Methods
Strong magnets outside fibreglass casing are used (fibreglass just over the interest zone) give a strong magnetic signal
Strain gauges bonded to the casing, inside or outside (best), wire leads to surface
Gravity logs (downhole gravimeter) Other behind-the-casing logs which are
sensitive to the lithology changes Tiltmeters can be placed in boreholes
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Real-Time GPS Monitoring SystemReal-Time GPS Monitoring System
antenna
site
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Site Monitoring ArraySite Monitoring Array
1.5 km2 site 25 inj/prod wells Progressive CSS Start at bottom, move
up row by row, soak, then produce till H2O
186 benchmarks placed Surveyed every 4-6 wk Deformations in the
elapsed time analyzed
wellsites
at depth
186 benchmark array
#8
#7
#6
#5
#4
#3
#2
#1
Wellrows
benchmarks
1 kilometre
limits of array
limits
of a
rray
Alberta example, steam injection pilot
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Measurement ParametersMeasurement Parameters
Precision must be acceptable (5% of zmax) No systematic errors if possible (random only) The number of measurement stations must be
chosen carefully, depending on goals If inversion needed, array designed rigorously Array must extend beyond reservoir limits to
capture the subsidence bowl Stable remote benchmark needed, etc.
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Deformation ArraysDeformation Arrays
z: Surface surveys, satellite imagery, aerial photography
shallow tiltmeters
deep tiltmeters
z, at surface : tiltmeters
V in reservoir
also, displacement measurements in holes can be used
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Fracture Monitoring as WellFracture Monitoring as Well
depth
Z
0.41Z
~1.0Z
-uplift linked to aperture-shape linked to geometry-skewness linked to asymmetry
fracture
surface deformation
tilt maxima
verthorz
Must use tiltmeters for fracturing because deformations are small
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
More About Deformations and Coupling More About Deformations and Coupling Flow and GeomechanicsFlow and Geomechanics
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Example of “The Coupling Issue”Example of “The Coupling Issue”
ΔT changes stresses… Stress changes lead to general shear Shearing changes transport properties Changed transport properties change the
temperature distribution! And so on… We can make similar conclusions about Δp So… Everything is coupled… How do we handle this?
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
A Pure Volume Change - A Pure Volume Change - ΔΔVV
Z
Surface deformation shapes
Δz]V
ΔVΔV
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
A Pure Shear Displacement - A Pure Shear Displacement - ΔΔSS
Z
Surface deformation shapes
ΔS
Δz]S
ΔS
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
ΔΔV + V + ΔΔS S DeformationsDeformations
Z
Surface deformation shapes
ΔV ΔS
Δz]V + Δz]S
ΔV ΔS
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Aerial PhotographyAerial Photography
Typically - 9-fold photogrammetric overlap, then, digital and statistical analysis to give 1-5 mm precisions
flight path
aircraft
special targets for precision
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Various Other MethodsVarious Other Methods
InSAR
surveys
tiltmeters borehole tilt
extensometers logging methods
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Earthquake Movements, Bam, IranEarthquake Movements, Bam, Iran
Differenced ground movements due to 2003 earthquake at Bam, Iran
Note the quadrupole configuration associated with the shear displacement event
InSAR Example
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
InSAR InterferogramInSAR Interferogram
•ERS1/2 SAR data•18-frame time series
•eight-year period 1992-2000
ground-subsidence for Phoenix, AZ
time series of transects
40 cm
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
mod. Stancliffe & van der Kooij, AAPG 2001
+285 mm
+200
-210
+260
+130 mm
-165
km
+100 Vertical displacements
(mm)
over 86 days
subsidence
heave
Imperial Oil – Cold LakeImperial Oil – Cold Lake
mega-row
CSS
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Belridge FieldBelridge Field, CA, CA - Subsidence- Subsidence30-40 cm per year
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
BelridgeBelridgeSubsidenceSubsidenceRateRate
over 18 months
0.0 in./yr
12.5
25.0
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
tShell Oil Canada – Peace RiverShell Oil Canada – Peace River
ref. Nickle’s New Technology Magazine, Jan-Feb 2005
Surface
uplift / tilt
data
reservoir inversion grid
with 50x50m grid cells
Multi-lateral
CSS
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Phase A
Deflection (mm) Deflection (mm)-10 0 10 20 -20 -10 0 10
120
140
DEPTH (m) WELL AGI3WELL AGI1
Mudstone& Sand
Oil Sand
ref Collins (1994); insert ref. Ito & Suzuki (1996)
160
180
Limestone
Expansive Lateral StrainsExpansive Lateral Strains
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Microseismic MonitoringMicroseismic Monitoring
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Microseismic MonitoringMicroseismic Monitoring
Large redistributions during production v changes in some zones
h as well, sometimes massively The formation shear strength is locally
exceeded, perhaps on a weak plane… Shearing in geological materials is a stick-slip
phenomenon, acoustic energy is emitted This can be used to track fronts and processes
to optimize in “real-time”
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Shearing Near a UCS FractureShearing Near a UCS Fracture
Shearing occurson the flanks ofthe fracture.
At the tip, parting occurs, little energy
Shearing during HF of SWR has been detected microseismically in the field on the fracture flanks.
Shearing is the major energy release process in HF!!
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Waterfrac Vs Gel StimulationWaterfrac Vs Gel Stimulation
Observation Well
Observation WellFrac Well
Perf zones
Geophone array
Craig CipollaPinnacle
Barnett Shale Microseismic Monitoring While Fracturing
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Waterfrac Vs Gel StimulationWaterfrac Vs Gel Stimulation
X-Link Gel FracWaterfrac Craig Cipolla
Pinnacle
Barnett Shale Microseismic Monitoring While Fracturing
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Waterfrac Vs Gel StimulationWaterfrac Vs Gel Stimulation
Craig CipollaPinnacle
Barnett Shale Microseismic Monitoring While Fracturing
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Waterfrac Vs Gel StimulationWaterfrac Vs Gel Stimulation
Craig CipollaPinnacle
Barnett Shale Microseismic Monitoring While Fracturing
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Arching of StressesArching of Stresses
“soft” region
Regions of high lateral
shear potential
Regions of high shear and dilation
Microseismic emissions from high shear regions
Compressive stress trajectories
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
MS Activity in CompactionMS Activity in Compaction
slip along near-horizontal,weak bedding planes
region oflateral
unloadingslip on curved
bedding planes
compaction
region of increasedlateral stresses
Note, the reservoir curvature is greatly exaggerated, x10 vertically,and the relative compaction is also greatly exaggerated
reservoir
MS emissions will delineate slip planes and activation of high-angle slip
In Ekofisk, MS monitoring helped elucidate mechanisms
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
MS Tracking of a Fireflood (1992)MS Tracking of a Fireflood (1992)
x
x
x
x
x x
x
x
xx x x
xx x
x x xx
x
x
x
x
xx
xx
x
x
xx
x
xx
xx
x
x
x
x
x
x
x x
x
xxx
x
x
x
x
x
x
x
x
x
x
xx
x
x
x x xx
x x
x
x
x x
x
xxx
x x
xx
x
x
xx
x
x
xx
xx
A
B
C
D
?? ?
?
A: good oil production
B: heated channelC&D: poor
production
injector plus four producers
stable front
unstablefront
no discrete front
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
MS & Integrated Monitoring…MS & Integrated Monitoring…
Shell Oil, Peace River
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Parallel Processing in MS ArraysParallel Processing in MS Arrays
sensorszone ofinterest
fibre-optics or telemetryworkstation
localprocessors1 2 3 4 5
monitoring or future production wells
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Time Lapse Seismic – 4D SeismicTime Lapse Seismic – 4D Seismic
The geomechanics coupled model is based on the mechanical earth model
The mechanical earth model comes from seismics, logs, cores, an correlations
Stress predictions are made from incorporating ΔT, Δp over time – Δt
Time Lapse seismic gives us Δ(V, Q…) We try to use this to calibrate and clarify the
geomechanics model so it becomes predictive in nature.
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
Integrated Monitor WellsIntegrated Monitor Wells
monitoring well
data acquisition Multiple functionsin a single well give
cost-effective monitoring capability
pressure sensors
temperature sensors
triaxial accelerometers
process well
Multiplexing and event detection algorithms make the collection and analysis of large data streams tractable
©MBDCI©MBDCI7-
F M
on
ito
rin
g a
nd
Ris
k M
anag
emen
t
CommentsComments
In conventional reservoir engineering, p and T measurements are needed
In coupled geomechanics, we need other types of measurements Deformations Changes in seismic attributes Microseismic emissions mapping and analysis
Allow us to calibrate and perfect models Which give us predictive capabilities Which allows us to protect our value chain
Top Related