Dinantian carbonates - Energie Beheer Nederland · carbonates (see fig. 1) and has led to a better...
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Dinantian carbonates Exploring potential for hydrocarbons and geothermal energy For questions contact [email protected] or [email protected] 0 20 40 60 80 100 km Distribution of Dinantian carbonates Dutch onshore and offshore border Wells that drilled Dinantian age rocks Dinantian facies Platform Platform possible Platform unlikely (basinal facies) London-Brabant Massif Exploration targets Exploration for hydrocarbons in the Southern North Sea Geothermal projects Ultra Deep Geothermal projects Underground Gas Storage (UGS) project in Belgium Projection: UTM, Zone 31N Map datum: ED50 Callifornie Mol UGS UHM-02 -1.5 - -2 2. .0 0 -2.5 -3.0 -3.5 0 0 1 1 2 2 3 3 4 4 5 5k km m -10.00 -7.50 -5.00 -2.50 0.00 2.50 5.00 7.50 Amplitude TWT [s] Z Ze ec ch hs st te ei in ns sa al lt t N NE E S SW W R Ro ot tl li ie eg ge en nd d W We es st tp ph ha al li ia an n N Na am mu ur ri ia an n D Di in na at ti ia an nc ca ar rb bo on na at te es s Prospective targets • The conceptual diagram in fig. 3 shows the different scenarios for karsficaon and/or fracturing of Dinanan carbonate reservoir – to be explored for. • The prospecve structures indicated in fig. 3 can be recognized on seismic data (see figs. 4 & 5). Changing views on reservoir quality: From tombstone to cave Dinanan carbonates have been underexplored because of the misconcepon that these rocks are always ght. Wells and seismic data, however, show the presence of fractured and karsfied (producing) reservoir. Underground gas storages wells in Belgium and recent geothermal wells in the Netherlands and in Belgium found highly permeable reservoir (fig. 2). Exploration targets • Offshore, in the P-quad, the Dinanan carbonates are being explored for hydrocarbons by a partnership led by Jetex. • Onshore, an Ultra Deep Geothermal exploraon work programme is being set up by EBN and TNO. This programme explores the potenal of the Dinanan Carbonates to supply high temperature heat (> 150 °C) to the process industry. The programme starts in early 2018 and will be coordinated by EBN. Post-Triassic 1 4 3 2 S N Permo-Triassic Upper Carboniferous Northern Netherlands Platforms Silurian-Devonian Basement North Frisian Black Shale Basin London-Brabant Shelf 1 Visean platforms 2 Tournaisian ramp Karst scenarios 1 2 1 1 The Lower Carboniferous Dinanan carbonates have recently become the target of exploraon for both hydrocarbons and geothermal energy in the Netherlands. Evaluaon of recent O&G and geothermal wells in Belgium and the Netherlands, combined with seismic mapping (e.g. Hoornveld, 2013 and Boots, 2014) has resulted in a new mapped distribuon of Dinanan carbonates (see fig. 1) and has led to a beer insight in the mechanisms leading to favourable reservoir quality. Figure 1. Distribuon map of the Dinanan carbonates. The dark blue indicates where a carbonate plaorm is proven by a well and/or where the seismic has clear indicaons for plaorm structures. Light blue indicates locaons without direct proof of plaorm facies, but where a local high in the Early Carboniferous is expected. (Modified from a TNO report on ultra-deep geothermal energy, Boxem et al., 2016) Figure 2. Core with karsfied Dinanan carbonate rock from Belgian UGS well. Figure 3. Locaons with a higher chance of karsficaon are indicated by orange ellipsoids. 1 Meteoric karsficaon takes place when the rocks are exposed at surface and fresh water flows through faults and fractures. 2 Hydrothermal karsficaon takes place when hot fluids flow upwards through deepseated faults. These fault zones will be fractured as well. 3 Intra-plaorm karsficaon takes place during sea level low stands in between periods of carbonate plaorm development. Indicaons for these first 3 scenarios have been found in wells and seismic data in recent studies. 4 Mixed coastal-zone karsficaon can occur when a carbonate plaorm is exposed to a mix of fresh and salt water. The edges of the plaorm will also be more prone to fractures as a result of slope instability. Figure 4. Seismic line through geothermal wells CAL-GT-01 and -03. This well (-01) encountered a cavity larger than 30 m and produces 240 m 3 /h. The seismic shows that the well was drilled into a fault zone. Evaluaon of samples indicates that the karsficaon and dolomisaon were caused by hydrothermal diagenesis (Poty, 2014). Figure 5. Example of a Dinanan carbonate plaorm visible on seismic. The well UHM-02 was drilled in the plaorm interior encountering a few, thin, karsfied zones. More fractured and karsfied, hence more permeable, carbonate rock may be found at the edges of the plaorm. 5 cm 0 -0.5 -1.0 -1.5 -2.0 TWT [s] 2 2k km m C CA AL L- -G GT T- -0 03 3 ( (p pr ro oj je ec ct te ed d) ) C CA AL L- -G GT T- -0 01 1( (- -S S1 1) ) ( (p pr ro oj je ec ct te ed d) ) W W E E Z Ze ec ch hs st te ei in n& &L L. .G Ge er rm ma an ni ic cT Tr ri ia as sG Gp p ( (P Pe er rm mi ia an n– –T Tr ri ia as ss si ic c) ) L L. .- -U U. .N No or rt th hS Se ea aG Gp p ( (C Ce en no oz zo oi ic c) ) C Ca ar rb bo on ni if fe er ro ou us sL Li im me es st to on ne eG Gp p ( (D Di in na an nt ti ia an n) ) B Ba an nj ja aa ar rd dG Gp p ( (D De ev vo on ni ia an n– –? ?D Di in na an nt ti ia an n) ) L Li im mb bu ur rg gG Gp p ( (~ ~N Na am mu ur ri ia an n) ) L Li im mb bu ur rg gG Gp p ( (~ ~W We es st tp ph ha al li ia an n) ) C Ch ha al lk kG Gp p ( (U U. .C Cr re et ta ac ce eo ou us s– –P Pa al le eo og ge en ne e) ) D Da at ta ac co ou ur rt te es sy yC Ca al li if fo or rn ni ië ë W Wi ij jn ne en nG Ge eo ot th he er rm mi ie eB B. .V V. .
Transcript of Dinantian carbonates - Energie Beheer Nederland · carbonates (see fig. 1) and has led to a better...
Dinantian carbonates Exploring potential for hydrocarbons and geothermal energy
For questions contact [email protected] or [email protected]
0 20 40 60 80 100 km
Distribution of Dinantian carbonates Dutch onshore and o�shore border Wells that drilled Dinantian age rocksDinantian facies Platform Platform possible Platform unlikely (basinal facies) London-Brabant Massif
Exploration targets
Exploration for hydrocarbons in the Southern North Sea
Geothermal projects
Ultra Deep Geothermal projects
Underground Gas Storage (UGS) project in Belgium
Projection: UTM, Zone 31NMap datum: ED50
Callifornie
MolUGS
UHM-02
-1.5
--22..00
-2.5
-3.0
-3.500 11 22 33 44 55kkmm
-10.00-7.50-5.00-2.500.002.505.007.50
Amplitude
TWT
[s]
ZZeecchhsstteeiinn ssaalltt
NNEE SSWW
RRoottlliieeggeenndd
WWeessttpphhaalliiaann
NNaammuurriiaann
DDiinnaattiiaann ccaarrbboonnaatteess
Prospective targets• Theconceptualdiagraminfig.3showsthedifferentscenariosforkarstificationand/orfracturingofDinantiancarbonatereservoir–tobeexploredfor.
• Theprospectivestructuresindicatedinfig.3canberecognizedonseismicdata(seefigs.4&5).
Changing views on reservoir quality: From tombstone to caveDinantiancarbonateshavebeenunderexploredbecauseofthemisconceptionthattheserocksarealwaystight.Wellsandseismicdata,however,showthepresenceoffracturedandkarstified(producing)reservoir.UndergroundgasstorageswellsinBelgiumandrecentgeothermalwellsintheNetherlandsandinBelgiumfoundhighlypermeablereservoir(fig.2).
Exploration targets• Offshore,intheP-quad,theDinantiancarbonatesarebeingexploredforhydrocarbonsbyapartnershipledbyJetex.
• Onshore,anUltraDeepGeothermalexplorationworkprogrammeisbeingsetupbyEBNandTNO.ThisprogrammeexploresthepotentialoftheDinantianCarbonatestosupplyhightemperatureheat(>150°C)totheprocessindustry.Theprogrammestartsinearly2018andwillbecoordinatedbyEBN.
Post-Triassic1
4
3
2
S N
Permo-Triassic
Upper CarboniferousNorthernNetherlandsPlatforms
Silurian-Devonian Basement
North Frisian BlackShale Basin
London-Brabant Shelf
1 Visean platforms2 Tournaisian ramp Karst scenarios
12
1
1
TheLowerCarboniferousDinantiancarbonateshaverecentlybecomethetargetofexplorationforbothhydrocarbonsandgeothermalenergyintheNetherlands.EvaluationofrecentO&GandgeothermalwellsinBelgiumandtheNetherlands,combinedwithseismicmapping(e.g.Hoornveld,2013andBoots,2014)hasresultedinanewmappeddistributionofDinantiancarbonates(seefig.1)andhasledtoabetterinsightinthemechanismsleadingtofavourablereservoirquality.
Figure 1.
Distribution map of the Dinantian carbonates. The
dark blue indicates where a carbonate platform
is proven by a well and/or where the seismic has
clear indications for platform structures. Light
blue indicates locations without direct proof of
platform facies, but where a local high in the Early
Carboniferous is expected. (Modified from a TNO
report on ultra-deep geothermal energy, Boxem et al.,
2016)
Figure 2.
Core with karstified Dinantian carbonate rock from Belgian UGS well.
Figure 3. Locations with a higher chance of karstification are indicated by orange ellipsoids. 1 Meteoric karstification takes place when the rocks are
exposed at surface and fresh water flows through faults and fractures. 2 Hydrothermal karstification takes place when hot fluids flow upwards through
deepseated faults. These fault zones will be fractured as well. 3 Intra-platform karstification takes place during sea level low stands in between periods of
carbonate platform development. Indications for these first 3 scenarios have been found in wells and seismic data in recent studies. 4 Mixed coastal-zone
karstification can occur when a carbonate platform is exposed to a mix of fresh and salt water. The edges of the platform will also be more prone to fractures
as a result of slope instability.
Figure 4. Seismic line through geothermal wells CAL-GT-01 and -03. This
well (-01) encountered a cavity larger than 30 m and produces 240 m3/h.
The seismic shows that the well was drilled into a fault zone. Evaluation of
samples indicates that the karstification and dolomitisation were caused by
hydrothermal diagenesis (Poty, 2014).
Figure 5. Example of a Dinantian carbonate platform visible on seismic.
The well UHM-02 was drilled in the platform interior encountering a few,
thin, karstified zones. More fractured and karstified, hence more permeable,
carbonate rock may be found at the edges of the platform.
5 cm
0
-0.5
-1.0
-1.5
-2.0
TWT
[s]
22 kkmm
CCAALL--GGTT--0033((pprroojjeecctteedd))
CCAALL--GGTT--0011((--SS11))((pprroojjeecctteedd))WW EE
ZZeecchhsstteeiinn && LL.. GGeerrmmaanniicc TTrriiaass GGpp((PPeerrmmiiaann –– TTrriiaassssiicc))
LL..--UU.. NNoorrtthh SSeeaa GGpp((CCeennoozzooiicc))
CCaarrbboonniiffeerroouuss LLiimmeessttoonnee GGpp
((DDiinnaannttiiaann))
BBaannjjaaaarrdd GGpp
((DDeevvoonniiaann –– ??DDiinnaannttiiaann))
LLiimmbbuurrgg GGpp
((~~NNaammuurriiaann))
LLiimmbbuurrgg GGpp
((~~WWeessttpphhaalliiaann))
CChhaallkk GGpp ((UU.. CCrreettaacceeoouuss –– PPaalleeooggeennee))
DDaattaa ccoouurrtteessyy CCaalliiffoorrnniiëëWWiijjnneenn GGeeootthheerrmmiiee BB..VV..
