INDUCED SEISMICITY IN NORTHEAST BRITISH...
Transcript of INDUCED SEISMICITY IN NORTHEAST BRITISH...
INDUCED SEISMICITY IN NORTHEAST BRITISH COLUMBIA
Dan Walker, P. Geol.,Senior Petroleum GeologistBritish Columbia Oil & Gas Commission
BC Laws provide public access to the current laws of British ColumbiaBC Laws provide public access to the current laws of British Columbia.
The list of Acts and Regulations by which the Commission operates is available via www.bcogc.ca.
Production2012 Reserves
40 TCF Gas
120 MMSTB Oil
102 MMSTB Condensate
40 TCF Gas
120 MMSTB Oil
102 MMSTB Condensate
277 MMSTB NGL277 MMSTB NGL
NortheastNortheast British Columbia shale gas play areasFort St. John
829 miles
The otherThe otherWashington
Shale Gas Stratigraphy
Horn River Basin
Evie Otter Park andEvie, Otter Park and Muskwa target zones
Upper and Lower Montney target zones
FORT ST JOHN GRABENSEPTIMUS BASIN– SEPTIMUS BASIN
From: Barclay et al Bulletin of Canadian P t l G lPetroleum Geology Vol 38A Dec 1990
From: Dr. ZeevBerger, CSPG Reservoir Issue 2, February 2009
Where are we at today?• >1000 proven/possible induced events
270 kilometres (168 miles)
p /p(mag 1 to 4.3)
• 6 events > magnitude 4.0, max event 4.3• 20+ events reported ‘felt’• Wellbore damage??
• Deformed casing at Etsho (?)C i d S ti (?)• Casing damage near Septimus (?)
• Cement damage (??)
CNSN array coverage 800
900Sample of event ratios
Seismicity red dots
coverage
200300400500600700
Series1
P d CNSN t ti
red dots0
100
Mag 1-2 Mag 2-3 Mag 3-4
Original CNSN seismograph stations
Proposed CNSN station
560 kilometres(348 miles)
Caribou – frac IS?, disposal IS?
SEISMICITY INCIDENTS UNDER REVIEW
Beg – frac IS?, disposal IS?
Graham – disposal IS ? Eagle/Eagle West –waterflood IS
Altares –Altares –Montney frac IS
Septimus –f IS?
Doe/Dawson fracIS?
frac IS?, disposal IS?
89 events, Mar 1985 – July 2013
Water-flood induced• Events areally confined• Pressure controlled , y
TATTOO7 EVENTS
(MAG 2.4 TO 3.1)
DEC 2011
TATTOO
ETSHO
31 EVENTS
(MAG 2.2 TO 3.8)
APRIL 2009 TO JULY 2011JULY 2011
Etsho-Tattoo (Mag vs Time)
2
3
4( g )
Mag
0
1
12/18/2008 07/06/2009 01/22/2010 08/10/2010 02/26/2011 09/14/2011 04/01/2012 10/18/2012 05/06/2013
d-1-D Pad
Frac- induced seismicity: occurs wi th in 300m of
in ject ion po int –
wellboresin ject ion po int in ject ion po int t rave ls
usual l y occur s wi th in 15 hr s of in jec t ion
s tops w i th end o f f rac ing
f i d t conf ined to re -act i vat ion zones
not t r iggered f rom d is tant in ject ion po ints
most ly in ta rget zoney g
Mitigation P u m p r a te s
Etsho Kiwiganag Tattoo
byp a s s i n g s t a g e s ex i t re -ac t i va t ion zone F l owb a c k
216 events (1 .0 to 3 .0Mw)
• 197 events (1 .0 to 2.0Mw)
0940
• 19 events (2.0 to 3.0Mw)
SHALE GAS FRAC-INDUCED EVENTS(MAGNITUDE VS TIME)
Sh l G F I d d E t
(MAGNITUDE VS TIME)
3.5
Shale Gas Frac‐Induced Events(Magnitude vs Time)
2.5
3Reactivation zone
1.5
2
magnitudeFault movement baseline?
0.5
1
006‐18‐2011 06‐25‐2011 07‐02‐2011 07‐09‐2011 07‐16‐2011 07‐23‐2011 07‐30‐2011 08‐06‐2011 08‐13‐2011 08‐20‐2011
‘ f au l t d r i ven events ’ – b - va lues 1 .1 to 1 .2
‘ f rac tu re d r i ven events ’ – b - va lues 1 .9
3.5Sh l G F I d d E t
events > 0 .5ML were ‘ fau l t d r i ven ’
2.5
3
Shale Gas Frac‐Induced Events (Mag vs Time)
1.5
2
0
0.5
1 mag
7 day intervals0
6/23/12 6/30/12 7/7/12 7/14/12 7/21/12 7/28/12 8/4/12 8/11/12 8/18/12 8/25/12 9/1/12 9/8/12 9/15/12 9/22/12 9/29/12 10/6/12 10/13/12 10/20/12 10/27/12 11/3/12 11/10/12 11/17/12 11/24/12 12/1/12 12/8/12
1
1.5
2
2.5
Series1
0
0.5
0 50 100
122 events, mag 1.6-4.0, Mar 2001- Sept 2013• Distant epicentres• Spatially randomp y• Magnitudes increase
w/volume
Water disposal well
4
5
Septimus Mag vs Time 122 events, Mag 0.2-4.2ML, Feb Aug 2013
1
2
3
4
Magnitude
Feb-Aug 2013
001/26/13 03/17/13 05/06/13 06/25/13 08/14/13
From: Dr. Zeev Berger, CSPG Reservoir Issue 10, November 2008
From: BCOGC MontneyFormation Play Atlas, October 2012, Mark Hayes
4
Beg Mag vs Time
0
1
2
3
Mag
008/18/2013 08/20/2013 08/22/2013 08/24/2013 08/26/2013 08/28/2013 08/30/2013 09/01/2013
10 events
Mag 1.5 - 3.4
Aug 2013
CONCERNS
Surface EffectsSurface Effects
Ground motion Public safety
Property Property damage
Disposal Wells
Wellbore Integrity Casing deformation
Wells
Reservoir breakthrough
Aquifer contamination
NOTIFICATION AND CONSULTATIONNOTIFICATION AND CONSULTATION
Cons l tat ion Informat ion shar ing phase &
Detect ion
Recorded by CNSN or d
Consultat ion - In format ion shar ing phase & Moni tor ing Recommendat ions
Describe known incidents and mitigation options to Operator
dense arrays
Felt Reports
Noti f icat ion
Recommend installation of dense array to identify accurate hypocentres
Recommend using dense array data to implement mitigation strategy
Phone calls
Info Collection Questionnaire
Area operations?
Bypass injection (stages) near re-activation zones
Avoid known problem faults – “we know which faults to look out for”p
Microseismic?
Known faults?
Felt reports or
which faults to look out for
Submit routine seismicity reports to OGC
Current requi rements spec i f ic to Order or Permit
Suspend operations if Magnitude 4.0 event wellbore damage?
p p gdetected
Report all events > Magnitude 2.0
REGULATORY INITIATIVESREGULATORY INITIATIVES
Formalize operational reporting requirements Actively fracing wellbores – near real-time reports
Dense array deployments – where, when, regular reports
Require microseismic monitoring when fracing near disposal wells
Require enhanced monitoring in high-risk areas, disposal q g g , pwells, ‘felt’ areas
Report magnitude 2.0 events and suspend operations at Magnitude 4.0g
Submission of microseismic
Disposal Wells – ongoing Engineering review
Wellbore Integrity – post event testing