5.3

61.0

138.4

Oceanic

Crust

41.0

MOHO

J-K syn-rift

23.052.2

40 km 547 km

Continental

Crust

Mantle

Paleozoic &

Precambrian

strata

Line 5600

the canadianbeaufort sea Line 5600 is the most seaward ‘strike’ line in the ArcticSPAN Beaufort survey. The 547-km-long line shows the vari-able basin architecture of the Cana-dian Arctic passive margin (vertical exaggeration is 2.5).

Arctic conditions can put man and equipment to the test in acquiring good quality data.

Gas Oil

36 geo expro may 2009 38 geo expro may 2009

Illustr

atio

n: F

ugro

©IO

N

©IO

N

ION’s ArcticSPAN program is taking an unprecedented first look at new exploration frontiers. They have acquired approximately 16,000 km of 2D data in eastern Beaufort Sea from 2006 to 2008. The surveys are designed for deep imaging using 18 second re-cords and 9,000 meter cables. The seismic lines are located in a geologically-oriented grid driving new ideas about total basin potential and crustal evolution.See full story starting on page 39.

geo expro may 2009 39

canada:

the beaufort seadeeP crustaL iMaGinGTh e Canadian portion of the Beaufort Sea has been the site of intense interest and bidding in recent licensing rounds. Regional reconnaissance 2D seismic programs designed to image down to the base of the Earth’s crust are redefi ning frontier basin evaluation.

thoMas sMith

arct

ic e

XPLo

rati

on

Fig 4

Fig 5

Banks Island

Fig 6

Figure 3 Recorder

Cou

rtesy

: IO

N

ArcticSPAN surveys located on the Free Air Gravity Map (gravity data from Arctic Gravity Project of Kenyon and Forsberg, 2001). The COB line is coincident with other interpretations until the thick Mackenzie Delta sediments mask the boundary.

40 geo expro may 2009

In June of 2008, BP Exploration Company spent a record $1.18 billion for a 202,380 hectare parcel in the Canadian Beaufort Sea north of Tuktoyaktuk, North West Territories. Th is surpassed the previous record of $585 million Imperial Oil and ExxonMobil Canada paid in 2007 for a 205,000 hectare exploration lease in the same area. Last year BP was awarded three leases covering 611,000 hectares. Two other leases were awarded in the same sale: a 41,000 hectare parcel was won by MGM Energy, ConocoPhillips Canada, and Phillips Petro-leum Canada, while ConocoPhillips Canada won a 196,000 hectare lease. Th e area is not new to leasing and exploration. Over 50 oil and gas discoveries have been made in the shallow waters of the Beaufort/Mackenzie delta area during the 1970s and 1980s with all of these still waiting development and trans-portation to markets. Devon Energy drilled the fi rst well in 15 years north of Canada’s mainland. Th eir Paktoa well was drilled over the 2005 and 2006 drilling seasons 180 km north of Inuvik, North-west Territories. In 2007, they announced it to be a major oil discovery with recoverable reserves estimated at 240MMbo. More recently, MGM Energy Corporation announced a gas discovery 175 km northwest of Inuvik near the Beaufort Sea. Government estimates have the area containing a signifi -cant percentage of Canada’s conventional oil and gas. Th e

Geological Survey of Canada estimated the mean undiscov-ered resources at 2.7MMm³ (16.8Bbo) inclusive of deep water (to 2,500 m) while the U.S. Geological Survey put a mean of 2.3MMm³ (14.5Bbo) and 2.32Tm³ (86.6Tcf; 15.6Bbo) gas in the basin in water depths less than 1,000 m.

ProGraM desiGn New tools and new approaches in geoscience are needed to help oil and gas companies meet reserve and production targets. One new approach developed by ION Geophysical’s GX Technology group (GXT) has been to acquire geologi-cally inspired and constrained programs know as SPANs. “SPANs are basin-wide, ultra-deep, 2D seismic data sets that are acquired and imaged using the most advanced geologi-cal and geophysical technology available,” says Joe Gagliardi, ION’s SPAN Program Director. “SPANs are custom designed to provide critical insight into the geologic evolution, deep basin architecture, deposition, and structural history of a petro-leum system. Th e resulting data provides oil and gas companies with new information, insights, and prospect generation op-portunities for under-explored or unexplored frontier basins. ION currently has 10 SPANs available and is in the detailed planning stage for additional programs worldwide.” Th e line shown on this issue’s seismic foldout (pages 36-38) was part of one of the three season programs from 2006 to

A

B

C

Figure 4 Recorder

Cou

rtesy

: IO

N

A. Dip line 4500 clearly shows the Beaufort Passive margin and the COB as a well defi ned fault. The interpreted MOHO, calculated from gravity data (red horizon) is signifi cantly deeper below the continental crust and observed on SPAN data.

iongeo.com/SPANS

BasinSPANSImaged by GXT

ee the big picture and make visionary decisions before the next licensing

round. ArcticSPANTM, part of ION’s worldwidedata library, provides basin-scale, ultra-deepseismic coverage of hydrocarbon systems beneath the U.S. Chukchi and Canadian Beaufort seas. Designed in collaboration with regional geoscience experts and processed by GXT, leaders in advanced imaging, ION’s ArcticSPAN surveys deliver unique insights that are unlocking new prospectopportunities. Take a new look at the Arctic’s exploration potential.

ION ArcticSPAN. More Insight. Less risk.

THERE IS MORE BENEATH THE SURFACE THAT OTHERS CAN’T SEE. BUT YOU CAN.

A R C T I C S P A N D A T A

ArcticSPANBasin-scale, Ultra-deep Data Program

DATA AVAILABLE FOR UPCOMING LEASE SALES

”Your Geophysical Services Partner”Management & Support of Geophysical Operations • Seismic Data Analysis • Positioning QC & Processing

Data Management • Consultancy Services • Software Development • Education & Training

Main offi ce: Geograf AS. Strandgt. 5 NO 4307 Sandnes • Tel. +47 5168 6910 • Fax +47 5168 6911US offi ce: Geograf US LLC 16000 Barkers Point Lane Suite 250 Houston, TX77079 • Tel. +1 713 375 1750 • Fax +1 281 497 1033

UK offi ce: AS Geograf 23 Manor GardensLondon SW20 9AB, UK • Tel. +44 (0)20 8540 0095 • Mob. +44 (0)7515 850544www.geograf.no

LOK

OM

OTI

V M

EDIA

AS

arct

ic e

xplo

rati

on

2008togather2Dlong-offset,reconnaissanceseismic data in the Canadian Beaufort Sea.More than16,000kmofdatawascollectedinageologicallydriven(oriented)gridalongthecontinentalmargin,fromtheU.S.bordertraversing the Mackenzie Delta shelf andslope northeast to the Amundsen Gulf andBanks Island. Depending on ice conditions,thelinesextendasfaraspossibleoffshoreandintodeep(over2,000m)water. “The Arctic SPAN program is typical ofour other Basin SPAN programs,” says Joe.“Wedesignedthisprogramtoimagedowntothebaseofthecrustwitha9kmlongcable,18secondrecordingandfinaldepthprocess-ing(prestackdepthmigration)to40km.Theseismicdataare interpretedtogetherwithsi-multaneously collectedgravity-magneticdatatoregionallymapthecrustalcontinent-oceanboundary(COB)andthetopoftheMOHOdiscontinuity.Theseismicdataistiedtoexistingwelldatatoidentifythemajorstratigraphicse-quences.ThisBeaufortsurveywasspecificallydesigned to image the entire crust andbasinarchitecturealongwithexcellentseismicreso-lutionwithinexplorationdepths(8km).”

a key line “The547km-longLine5600 is themostseaward strike line in the Beaufort surveyandthemostdramatic,revealingthevariablebasin architecture in three distinct crustaldomains,”saysDr.MennoDinkelman,ION’schiefgeologist.“ThesouthwestendtraversestheBeaufortfoldandthrustbeltofthehighlyprospective offshore Mackenzie Delta. Thefoldbelthasaverydeep(15km)detachmentzone overlying oceanic crust, including theinferred southward extension of the buriedmid-ocean ridge beneath the deformationfront. The central portion of the line is indeep water (>1,000 m) with flat lying sedi-mentsonoceaniccrust.Theeasternpartoftheline crosses theContinent-OceanBoundary(COB)ofthepassivemarginalongtheBanksIslandshelf.Thislinealsotiestheentire15+km-thick Canada Basin Megasequence ofLateJurassictoRecentagefromtheareawithwellcontrolinthesouthtothefrontierexplo-rationterritorytothenorthatoffshoreBanksIslandthathasthusfarnotbeenpenetratedbywells.”

passive margin ThecentralportionofLine5600showsthemost important stratigraphic sequencesdes-ignatedbyage.ThePlio-Pleistocenesequence(0-5.3Ma) ismore than3km thick.Manyintra-sequenceunconformities,erosional,andtruncation features are seen in the Miocene(23.0Ma)andyoungersedimentsseawardoftheshelfedgeontothecontinentalslope.TheValanginian(136.4Ma)breakupunconformi-tysyn-riftblocks,andthetopoffaulted,tiltedblocksofoceaniccrustareclearlyshown. TheopeninghistoryoftheCanadianBasinhas been debated for years. “Although manyquestions remain and need to be more fullyinvestigated,as it standsnowtheSPANdataappear to supporta rotationalopeningof thebasinandanextensionofthe‘paleo-spreadingcenter’ to near the mouth of the MackenzieRiver,”saysDr.Dinkelman.“Wealsohaveiden-tifiedapassivemarginboundarythatextendsalong the Tuk Peninsula and Banks Island.ThecontinuationintotheAlaskaBeaufortSeaismaskedby the thicknessof theMackenzieDelta sediments. Our interpretation wouldsuggest that a significant part of the delta isunderlainbyoceaniccrustwhichappearstobemoreexpansivethanpreviouslymapped.”

Figure 5 Recorder

Cou

rtesy

: IO

N

B. Line 3700 showing the compressional features in the Eocene to Miocene Beaufort Foldbelt. The detachment surface is located near the 136.4 Valanginian breakup horizon and the “outer high” caused by the Late Tertiary inversion is clearly shown.

42geoexpromay2009

www.blueback-reservoir.com

- A Petrel™ plug-in product for integration of electromagnetic data with seismic and reservoir data

BRIDGE EM Data Integrator

Want a demo? - contact sales@blueback-reservoir.com, or come and see us at stand #2538 at the EAGE exhibition in Amsterdam

TM

”BRIDGE is THE tool for making EM data more accessible and usable to the geosciences world”

beaufort foldbelt Thestructuralstylechangesonthesouth-easternportionofLine5600.Gravityslidingand Brooks Range compression in north-easternAlaskahavecreatedfoldsandthrustsin the highly prospective offshore BeaufortFoldbelt. The master detachment level liesat approximately 15 km depths along thesouthern and western parts of the area.Thewelldevelopedgrowthsynclinesbetweenthegreenandpink reflectors (LateEocene,41-34Ma)indicatetheageofthemainfoldingevent.Ayounger,late-Tertiarycompressionalevent caused the structural inversion, foldedthe detachment surface, and created a largestructureattheshelfedgewhichextendsintodeeperwaters. “This inversion structure is located wherewe have postulated the presence of a nowinactivespreadingcenterunderthedeltasedi-ments,”saysDr.Dinkelman

prospective eastern section Theeasternendofthelineoverliescon-tinental crust. At the continental margin,high angle, basin-bounding faults separatethe Paleozoic sequences mapped on theCanadian Arctic Islands from the oceaniccrust and rift-sediments.This transition atthe COB is interpreted as a major crustalfault. “The Meso-Cenozoic stratigraphy is wellimagedandattainsathicknessinexcessof12km,”saysDr.Dinkelman.“Thisisconsiderablythickerthanpreviouslythoughtwouldbethecasewiththisoffshoreareabeingmorethan300kmfromtheMackenzieRiversedimentsource. In addition, in the deeper watersoffshore the southeastern edge of BanksIsland, amajor rollover feature is imaged inLate Cretaceous and younger sedimentarysequences alongoneof themajordown-to-

the-basindippingfaultsseawardoftheCOB.Thefullextentofthisfeaturehasnotyetbeenmapped but suggests hydrocarbon trappingpossibilitiesalongthisboundary.Therolloverisalmost30kmwideandhasnearly800mofstructuralrelief.” Landward, the Paleozoic section is dis-rupted by down-to-the-basin faults. DepthtotheMOHOisalmost30kmbeneaththehighly-reflective,lowercontinentalcrustneartheterminationofLine5600. “Whetherdealingwithexplorationfron-tiers in the Arctic margins or synthesizingregional tectonics in established petrolifer-ousprovincessuchastheMackenzieDelta,these state-of-the-art deep seismic surveysprovide thought provoking illumination ofbasin scale tectonics and crustal architec-ture,”Dr.Dinkelmanconcludes.“Wehaveafirmfoundationforbasinanalysisandassess-ment.”

arct

ic e

xplo

rati

on

Figure 6 Recorder

Cou

rtesy

: IO

N

C. The east end of Line 5600 showing a very thick Late Cretaceous and younger sedimentary section at a considerable distance from the Mackenzie Delta area. A very large rollover into a fault is clearly imaged on the line.

44geoexpromay2009