DataPDF Available

Looking for a New Player in Old Terranes - is there any shale gas potential in Southern Portugal ?

Data

Looking for a New Player in Old Terranes - is there any shale gas potential in Southern Portugal ?

Figures

No caption available
… 
No caption available
… 
No caption available
… 
No caption available
… 
No caption available
… 
Content may be subject to copyright.
Looking'for'a'New'Player''
in'Old'Terranes''
–"is"there"any"Shale.Gas"poten2al""
in"Southern " Portugal?"!
Sousa,'J.
(1)'
;'Silva,'C.'
(1)'
;'Guerreiro,'L.
'(1)'
;'Barberes,'G.
(2)
;'
Azevêdo,'M.
'(3)'
;'Pena'dos'Reis,'R.
(2)'
.;'Fonseca,'P.
'(4)
;'
'Pimentel,'N.
'(4)'
;'Barreto,'P.
'(1)'
'
!"#$Partex'Oil'&'Gas%$&'()*+%$,*-./012$$
!3#$41-.5$67'8+78($98:;%$Coimbra'Univ;%$,*-./012$$
!<#$ALS'Petrophysics%$=/'2>?*->%$6/--8@%$AB$$
!C#$=8*2*0@$98:;%$Lisbon'University%$,*-./012$$
PRESENTATION'OUTLINE'
$
$
";DEFGH9AIFDHE$
3;=4H&H=DIJ&$KGJL4MHGB$
<;J,,GHJIN46$
C;E4M$9JFJ$
O;DL,&DIJFDHE6$
P;IHEI&A6DHE6$
1. INTRODUCTION'
D+$ .58$ 21(.$ ?8Q$ @81-($ (8R8-12$ 1/.5*-($
Q*-S8>$ .*$ :-*R8$ .58$ 5@>-*71-)*+$
:*.8+T12$ */.('>8$ .58$ ,*-./0/8(8$
L8(*U*'7VI8+*U*'7$)1('+(;$$
$
F58$W1X*-'.@$*?$.58$Y82>$Q*-S$?*7/(8>$*+$
21.8$ ,128*U*'7%$ I1-)*+'?8-*/($ .87.*+*V
(.-1T0-1:5'7$ /+'.($ *?$ .58$ Z1'[*$ J28+.8X*$
K2@(75$ =-*/:$ !ZJK=#%$ *+8$ *?$ .58$ W*(.$
-8:-8(8+.1TR8$ >*W1'+($ *?$ 6*/.5$
,*-./0/8(8$\*+8$!6,\#;$$
2.'GEOLOGICAL'FRAMEWORK'
'
F58$ 6,\$ '($ 1((*7'1.8>$ .*$ 1+$ 1+7'8+.$
.8--1+8]2'.5*(:58-'7$:21.8$(/)>/7.8>$
)8+81.5$ +*-.58-+$ H((1VL*-8+1$
\*+8%$>/-'+0$.58$N8-7@+'1+$*-*08+@;$
F58(8$ .8--1+8($ 1-8$ :1-.8$ *?$ .58$
D)8-*VJ-W*-'71+$ J-7%$ Q5'75$ 8[.8+>($
.5-*/05*/.$ .58$ J-W*-'71+$1+>$
G58+'(5$1+>$Z*58W'1+$L1(('?(;$
Ribeiro!et!al.,!2010!
M4D&$4F$J&;%$3^^_$
5`:a]]X0(;2@8227*2287T*+;*-0]7*+.8+.]"Pb]"]"3b]K";21-08;X:0$
HR8-2@'+0$ 1$ R*271+*V(8>'W8+.1-@$
7*W:28[%$ .58$ ZJK=$ -8:-8(8+.($ .58$ >'(.12$
(87.*-%$1Q1@$?-*W$.58$177-8T*+1-@$:-'(W$
1+>$'($+*Q$.58$W1'+$*/.7-*::'+0$0-*/:%$
Q5'75$ +*Q1>1@($ :-8(8-R8($ 1$ 2*Q$ 0-1>8$
-80'*+12$ W8.1W*-:5'7$ .-8+>$ >87-81('+0$
(*/.5Q8(.Q1->(;$$
3.'APPROACHES'
F58$ 1W*/+.$ 1+>$ >'(.-')/T*+$ *?$ 1R1'21)28$
08*758W'712$ >1.1$ '+7-81(8>$ *R8-$ .58$ :1(.$
@81-(%$1.$281(.$?*-$(*W8$(87.*-($*?$Z-8X8'-1%$
L'-1$1+>$Lc-.*21$K*-W1T*+($!ZJK=#;$$
G878+.$ Q*-S($ .8(T?@$ :-8R'*/($ *)(8-R1T*+($
/('+0$.-1>'T*+12$1+12@T712$W8.5*>(;$$
BIBLIOGRAPHIC!DATA!!V$H-01+'7$L1./-1T*+$!G*d#$'+$6M$,*-./012$$
!L7$I*-W17S$8.$12%$3^^be$K8-+1+>8($8.$12;%$3^"3#$
Black$f$L7I*-W17S$8.$12%$3^^b$
g822*Q$f$K8-+1+>8($8.$12;%$3^"3$
=-88+$f$,1-.8[]G8:(*2%$3^"<$
G8>$f$,1-.8[]G8:(*2%$3^"<$
BIBLIOGRAPHIC!MATURATION!DATA!SHOW!DIFFERENT!
SCENARIOS!
$4,DL4FJLHG,ND6L$!L7$I*-W17S$8.$12;%$3^^be$K8-+1+>8($8.$12;%$3^"3#$$
DIAGENESIS!/!ANQUIMETAMORPHISM!(J)1>$8.$12;%$3^"^#!
DIAGENESIS!!FND6$MHGB%$)1(8>$'+$=1WW1$G1@$7*--821T*+#$
L
J
F
A
G
J
F$
D$
H
E$
=1WW1$ -1>'1T*+$ 51($ :-*R8+$ /(8?/2$
8(:87'122@$ '+$ -821T*+$ .*$ .58$ *-01+'7$
W1./-1T*+$ 8(TW1T*+%$ 1($ Q822$ 1($ *+ $
5@>-*71-)*+$ -1>'*W8.-'7$ 1+*W12'8($
'>8+TY71T*+;$$
J'-)*-+$=1WW1$G1@$$
!644$,H6F4G$HA6D94#$
4.'NEW'DATA'
J2.5*/05$(*W8$*?$.58$FHI$>1.1$
-878+.2@$ 17h/'-8>$ (5*Q$
-81(*+1)28$ R12/8(%$ (8R8-12$
h/8(T*+($ W1@$ (T22$ (.1+>$ 1+>$
+88>$?/-.58-$'+R8(T01T*+;$$
,1-.$ *?$ .5*(8$ (1W:28($ :-8(8+.$
R'.-'+'.8$-8i87.1+78$R12/8($
/+>8-$ 3;OdG*$ 1+>$
7*+(8h/8+.2@$ .58$ :*.8+T12$ ?*-$
1+$ /+7*+R8+T*+12$ (5128$ :21@$
-8W1'+($1+$*:8+$:*((')'2'.@;$$
65*/2>$ .5*(8$ 2*Q8-$ .51+$
1R8-108$ R12/8($ )8$ 7*+('>8-8>$
R12'>j$$
L1./-1T*+$
8(TW1T*+%$
)1(8>$'+$F5]B$
7*--821T*+$$
E8Q$FHI$>1.1$
!M81.58-?*->$
&1)*-1.*-@#$
D.$ '($ :*((')2 8$ .51.$ (*W8$ :*.8+T12$
W'05.$(T22$)8$:-8(8+.$'+$1+@$: -8(8-R8>$
(.-/7./-8(;$$
9/8$ .*$ .58$ 5'05$ 7*W:28['.@$ *)(8-R8>$
1.$.58$(/-?178%$-80'*+12$(.-/7./-12$1+>$
.58-W12$ W*>82($ +88>$ .*$ )8$ 1>X/(.8>$
.*$8[:21'+$.58$1)*R8$*)(8-R1T*+(;$$
5.'IMPLICATIONS'
K/-.58-W*-8%$ 01($ (5*Q($
*)(8-R8>$ *+(5*-8$ L8(*U*'7$
&/('.1+'1+$ Z1('+$ Q8-8$
>8(7-')8>$ 1($ :-*)1)2@$ )8'+0$
(*/-78>$ ?-*W$ 21.8$ ,128*U*'7$
/+'.(;$$
F5'($ 1((/W:T*+$ (/008(.($ 1$
W*>82$ Q58-8$ ZJK=$ 71+$ )8$
7*+('>8-8>$ 1($ 1+$ 1+ 12*0/8$
(*/-78$?*-$.58$(*/.58-+$L8(*V
78+*U*'7$)1('+(;$$
&1.8$ ,128*U*'7$ *-01+'7$
W1./-'.@$ '+$ 6,\$ '($ +*Q$ ?1'-2@$
-8:-8(8+.1TR8$ 1+>$ 1::1-8+.2@$
W*(.2@$ :*(.VW1./-8%$ )/.$ Q51.$
51::8+($ .*$ .58$ I1-)*+'?8-*/($
)217S$ (5128($ 1Q1@$ ?-*W$ W1'+$
W8.1W*-:5'7$ U*+8($ *-$ '+$ .58$
*k(5*-8j$$
ALGARVE"BASIN"
ALENTEJO""
BASIN"
6.'FINAL'REMARKS'
'
A+7*+R8+T*+12$-8(8-R*'-$8[:2*-1T*+$Q*-2>Q'>8$
12-81>@$:-*R8>$.51.$-87':8($1-8$*l8+$>'k8-8+.$$
?-*W$:21@$.*$:21@;$$
$
98(:'.8$(*W8$:-*W'('+0$08*758W'712$-8(/2.(%$$
W1+@$*.58-$:1-1W8.8-($1-8$7-/7'12$$
.*$:-*R8$:21@$?81(')'2'.@$'+$.5'($-80'*+$$
1+>$1$2*+0$Q1@$.*$0*$'($(T22$1581>;$$
$
K/-.58-W*-8%$.58$(/778((?/2$JW8-'71+$L*>82$$
?*-$/+7*+R8+T*+12$-8(*/-78($>8R82*:W8+.$$
51->2@$Y.($4/-*:81+$(.1+>1->(;$$
$
Can'the'Old'Con\nent'aspire'to'keep'in'the'race?''
REFERENCES'
J)1>%$D;%$L1.1%$L;,;%$E'8.*%$K;%$m82'221%$E;$!3^^"#$V$F58$,5@22*('2'71.8($'+$>'108+8T7VW8.1W*-:5'7$-*7S($*?$.58$6*/.5$,*-./0/8(8$
\*+8%$(*/.5Q8(.8-+$,*-./012;$F58$I1+1>'1+$L'+8-12*0'(.$<_%$"Ob"V"On_;$
Z1-)8-8(%$ =;J;e$ ,8+1$ >*($ G8'(%$ G;e$ ,'W8+.82%$ E;&;e$ K*+(871%$ ,;4;e$ JU8R8>*%$ L;$ ! 3^"C#$ V$ N@>-*71-)*+$ 1+*W12'8($ '+$ .58$
I1-)*+'?8-*/($/+'.($*?$.58$6*/.5$,*-./0/8(8$\*+8$/('+0$.58$F5*-'/WVE*-W12'U8>$W8.5*>$!=1WW1$-1>'1T*+#;$=4H6NJ&4$3^"C$
Z1-)8-8(%$=;J;e$,8+1$>*($G8'(%$G;e$,'W8+.82%$E;&;e$K*+(871%$,;4;e$JU8R8>*%$L;$$!3^"C#$V$65128$01($:*.8+T12$'+$I1-)*+'?8-*/($/+'.($
*?$.58$6*/.5$,*-./0/8(8$\*+8a$1$:-82'W'+1-@$1((8((W8+.$;$=4H6NJ&4$3^"C$
K8-+1+>8(%$,;%$L/(0-1R8%$o;J;%$I21@.*+%$=;%$,8-8'-1%$\;%$H2'R8'-1%$o;F;%$=**>5/8%$G;%$G*>-'0/8(%$Z;%$3^"3;$E8Q$8R'>8+78$7*+78-+'+0$
.58$.58-W12$5'(.*-@$*?$98R*+'1+$1+>$I1-)*+'?8-*/( $-*7S($'+$.58$6*/.5$,*-./0/8(8$\*+8;$o*/-+12$*?$.58$=8*2*0'712$6*7'8.@$*?$
&*+>*+$"P_%$PCbVPOC;$
K*+(871%$,;4;e$JU8R8>*%$L;e$,'W8+.82%$E;&;e$,8+1$>*($G8'(%$G;e$Z1-)8-8($%$=;J;$!3^"C#$V$F87.*+'7$>8?*-W1T*+a$0**>$*-$)1>$?*-$
(5128$01($8[:2*-1T*+j$F58$71(8$*?$.58$6M$D)8-'1+$m1-'(71+$I51'+$;$=4H6NJ&4$3^"C$$
L7I*-W17S%$E;e$ I21@.*+%$=;e$K8-+1+>8(%$,;$!3^^b#$V$F58$ .58-W12$5'(.*-@$*?$ .58$A::8-$,1218*U*'7$ -*7S($*?$(*/.58-+$ ,*-./012;$
L1-'+8$1+>$,8.-*28/W$=8*2*0@%$3C$!<#%$"COV"O^;$
H2'R8'-1%$o;F;$!"_n<#$V$F58$W1-'+8$I1-)*+'?8-*/($*?$6*/.5$,*-./012a$J$(.-1T0-1:5'7$1+>$(8>'W8+.*2*0'712$1::-*175;$D+a$&8W*($>8$
6*/(1%$L;o;%$H2'R8'-1%$o;F;$!4>(#;$F58$I1-)*+'?8-*/($*?$,*-./012%$L8Wp-'1($>*$68-R'q*$=8*2p0'7*$>8$,*-./012%$,*-./012$3_%$<V<b;$
H2'R8'-1%$ o;F;%$ G82R1(%$ o;%$ ,8-8'-1%$ \;%$ L1.*(%$ o;r;%$ G*(1%$ I;%$ G*(1%$ 9;%$ L/+5s%$ o;L;%$ K8-+1+>8(%$ ,;%$ o*-08%$ G;%$ ,'+.* %$ J;%$ !3^"<#$ V$
=8*2*0'1$>1$\*+1$ 6/2$,*-./0/8(1%$7*W$t+?1(8$+1$8(.-1T0-1Y1$ 8$+1$R/271+*2*0'1$u('71%$08*h/vW'71$ 8$W'+8-12'U1qw8($>1$K1'[1$
,'-'.*(1;$D+a$9'1(%$G;%$J-1xX*%$J;%$F8--'+51%$,;%$B/22)8-0%$o;I;$!4>(#$=8*2*0'1$>8$,*-./012$m*2/W8$D%$4(7*21-$4>'.*-1%$Pb<fbPb;$
G')8'-*%$J;%$L/+5s%$o;%$9'1(%$G;%$L1.8/(%$J;%$,8-8'-1%$4; %$G')8'-*%$&;%$K*+(871%$,;4;%$J-1xX*%$J;%$H2'R8'-1%$o;F;%$G*Wy*%$o;%$I51W'+c%$
N;D;%$I*S8%$I;%$,8>-*%$o;$!3^^b#$V$=8*>@+1W'7$8R*2/T*+$*?$.58$6M$4/-*:8$m1-'(7'>8(;$F87.*+'7($3P%$3C:$
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
The Late Palaeozoic rocks of southern Portugal have a complex thermal history. Vitrinite reflectance determinations from 90 samples confirm that the organic maturity of Late Palaeozoic rocks in SW Portugal is very high, mainly corresponding to meta-anthracite coal rank. The optic fabric of vitrinite in oriented coal samples from the Brejeira Formation suggests maturation under simple, non-tectonic, burial conditions with peak temperatures being attained prior to Variscan deformation. The lack of any increase in vitrinite reflectance with depth through c. 1 km of section in borehole AC-1 is not consistent with conductive heat transfer and is interpreted as the result of late synorogenic to post-orogenic advective heating. This heating episode generated temperatures sufficiently high to produce levels of maturity corresponding to meta-anthracite coal rank through much of the terrane now exposed, but not high enough to result in overprinting of the pre-deformation optic fabric of vitrinite in the thin coals. The slightly lower maturity of older, platform-facies rocks in the Aljezur-Bordeira area may reflect either deposition on a basement high followed by less burial than adjacent parts of the basin, or the area being the site of a sink for descending relatively cool fluids.
Conference Paper
Full-text available
Portugal has no exploitable reserves of natural gas, therefore depending on hydrocarbon imports to meet all the country needs. The exploration of potential gas reserves in the country would represent a new era of energy production in Portugal. Such production is potentially possible from shales, a hydrocarbon source rock which outcrops in some regions of the country. This paper refers the preliminary study on the potential of some lithostratigraphic units consisting of shales, located in the South Portuguese Zone (SPZ), which integrate the Baixo Alentejo Flysch Group (Culm): Mértola, Mira and Brejeira Formations. These units of lower/upper Carboniferous age consist of a succession of deep turbidite sediments, in some areas further than 5 km in thickness, which cover more than half of the SPZ depositional area at the southwest of the Iberian Peninsula, in the Beja and Faro districts. © 2014, LNEG – Laboratório Nacional de Geologia e Energia IP.
Conference Paper
Full-text available
High volumes and low deformations are some of the peculiar features responsible for the increasing success of shale gas exploration activities, mainly in North America. In fact, the most important explored shale gas deposits (about 50% or more of the total gas) are located at depths between 1 and 3 kilometres, show significant spatial continuity (of several tens of kilometres) and thickness (about 300 meters), display low angle to horizontal deep and are undisturbed in terms of fragile and ductile deformation. These exceptional conditions can promote relatively high exploration rates. However, they can only be found at wide continents with large cratonic regions, not affected by orogenies and/or if affected by important tectono-metamorphic events deformation, folding patterns show high amplitude and low frequency wavelengths. In Iberia, the high deformation associated with the three main stages of the Variscan Orogeny, was used as an argument for not proceeding with prospection/exploratory projects of promising lithotypes. In fact, during the Variscan Orogeny, the Iberia was affected by several deformation stages, but there is no reason to exclude that some of the long flanks of the resulting folding patterns may have important volumes of rocks bearing high quality indexes for the exploration of shale gas. Recent studies developed in Portugal (SW Iberian Variscan Chain, South Portuguese Zone and Iberian Pyrite Belt) - based on the analysis of total organic carbon, maturation (both organic and inorganic) and gamma-ray data -, revealed the occurrence of potential lithotypes and favourable conditions for the existence of shale gas. At the South Portuguese Zone (SPZ), it is possible to identify some units (Mértola, Mira and Brejeira Formations) which seem to be able to accommodate interesting volumes of gas, but they are associated to important deformation. In this case, the values of porosity and the microfracturation seem to be more important than the deformation style and consequent regional fracturation. Moreover, the thickness of those formations can be also very favourable to the existence of shale gas, as they frequently overpass one or two hundreds of meters, considered as appropriate for gas accumulation. As so, the SPZ should not be excluded as a potential unconventional petroleum system, thus displaying great potential for shale gas exploration.
Article
Full-text available
Devonian and Carboniferous metasedimentary sequences in the southernmost sector of the Iberian Massif, part of the Hercynian Orogen in southwestern Portugal, contain shales and slates of low but variable metamorphic grade. These rocks have been studied by optical microscopy and XRD to obtain basic data on their clay mineralogy and crystal-chemical parameters (IC, the index of "crystallinity", b and d 001). Electron-microscopy techniques (SEM, HRTEM and AEM) have been used to characterize the textural relationships and chemical evolution of the minerals, mainly the phyllosilicates. A good correlation has been found between the data determined by XRD methods and by electron microscopy. The main mineral association is quartz + dioctahedral K-rich mica + feldspars, but Na–K intermediate mica, paragonite, kaolinite and chlorite also are present, although discontinuously. The thickness of crystallites measured directly from lattice-fringe images is related to the IC, providing information on the evolution of the metamorphism through the sequences, with decreasing IC from southwest to northeast. The IC values for both the Brejeira and Mira formations correspond to diagenesis and anchizone, the Mértola and Phyllite–Quartzite formations, to high anchizone–epizone, and the Pulo do Lobo Formation presents values typical of epizonal conditions. Despite this pattern of evolution, however, the changes in metamorphic grade are not progressive, and the abrupt changes found between the characteristic values of each stratigraphic formation are interpreted as being associated with thrust surfaces. Textural data provide a clear contrast between the samples of different grade, with the lowest-grade samples showing a bedding-parallel microfabric and stacks of phyllosilicates. The most strongly metamorphosed pelites, on the other hand, present a crenulation-cleavage microfabric and a recrystallized matrix. As grade of metamorphism increases, crystal thickness increases and defects decrease in the phyllosilicates, although chlorite shows a higher density of strain-related defects than mica. There is wide scatter in the chemical data for both dioctahedral micas and chlorites, but some chemical characteristics can still be discerned. XRD and AEM reveal a tendency for the micas to be more similar to muscovite and less to illite with increasing metamorphic grade, although both compositions are present in all samples. The extent of phengitic substitution is extremely low, indicating low-pressure conditions. The formation of chlorite and its composition are mainly controlled by the host-rock composition.
Article
Vitrinite reflectance (VR) evidence suggests that Palaeozoic rocks in the South Portuguese Zone of southwest Portugal are strongly post-mature, with mean VR (Rr) of 4.28%. Results from a thin Carboniferous coal are very similar to those from associated mudrocks, suggesting that the results from mudrocks in the region are not significantly influenced by the presence of reworked vitrinite particles. Integration of stratigraphic evidence with VR results from a field-oriented Carboniferous coal sample indicate that peak temperatures were attained post-Hercynian deformation, within the late Carboniferous–late Triassic interval. Results from the aureole of a minor Mesozoic igneous intrusion suggest that these intrusions did not significantly increase the already high maturation level of the Palaeozoic country rocks. VR (Rr) values from Triassic, Jurassic and Cretaceous sections that unconformably overlie the Palaeozoic rocks are much lower (0.87–1.14%) than those from the Palaeozoic and are fully consistent with recorded stratigraphic thicknesses and burial at geothermal gradients of 20–30 °C km−1.
  • J T Oliveira
  • J Relvas
  • Z Pereira
  • J X Matos
  • C Rosa
  • D Rosa
  • J M Munhá
  • P Fernandes
  • R Jorge
  • A Pinto
Oliveira, J.T., Relvas, J., Pereira, Z., Matos, J.X., Rosa, C., Rosa, D., Munhá, J.M., Fernandes, P., Jorge, R., Pinto, A., (2013) --Geologia da Zona Sul Portuguesa, com ênfase na estraTgrafia e na vulcanologia usica, geoquímica e mineralizações da Faixa Piritosa. In: Dias, R., Araújo, A., Terrinha, P., Kullberg, J.C. (Eds) Geologia de Portugal Volume I, Escolar Editora, 673-767.