UNCONVENTIONAL OIL & GAS POTENTIAL IN PORTUGAL

Transcription

1 UNCONVENTIONAL OIL & GAS POTENTIAL IN PORTUGAL Nuno PIMENTEL, LISBON UNIVERSITY Rui PENA DOS REIS, COIMBRA UNIVERSITY

2 UNCONVENTIONAL OIL & GAS POTENTIAL IN PORTUGAL GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET PRELIMINARY EXPLORATION ACTIVITIES IMPROVING TECHNICAL KNOWLEDGE TO SUPPORT DECISION-MAKINGS.

3 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL What are we talking about? What are we looking for? Shales which act both as SOURCE-ROCK and RESERVOIR. Organic rich shales, with good maturation and also with good properties to become a good reservoir (by Fracking).

4 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL Geological formations with: Good Organic content : TOC > 2%; Type II Good Maturation for Gas : Temp : 120ºC to 300ºC Ro% : 1.1 to 3.5 Depth: 3 to 9 km (T grad?) Tmax : 480ºC to 550ºC

5 Good Petrophysical properties Effective Porosity : > 4% Permeability : > 100 md Frackability : silica content

6 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL How can we find such geological units? Geological maps Geological characterizations Bibliographic references Reports (non-published) Field-work (reconnaissance studies)

7 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL A) PALEOZOIC UNITS SOME EXAMPLES (Overview) Northern and Central Portugal Lower Paleozoic deep marine shales Carboniferous continental shales Southern Portugal Carboniferous turbiditic sequences with deep marine black-shales

8 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL A) PALEOZOIC UNITS Late Paleozoic collision of terranes, With intense deformation and metamorphism controlling (over?)maturation Different paleogeographic Zones, with distinc units, metamorphism And potential CIZ OMZ Simancas et al., 2009 SOME EXAMPLES (Overview) SPZ Francke, 1989

9 N CENTRAL-IBERIAN ZONE CAMBRIAN Graphytic Black-shales in turbiditc sequences (Bateira Formation) c. 800 m thick > 500 km2 > 1km deep

10 N CENTRAL-IBERIAN ZONE CAMBRIAN ORDOVICIAN Pyritic Black-shales in turbiditc sequences (Ribeira Formation) 100 meters thick > 100 km2 >400 m deep

11 N OSSA-MORENA ZONE ORDOVICIAN Cruziana Black-shales (Barrancos Formation) 1000 meters thick > 700 km2 > 600 m deep

12 N SOUTH-PORTUGUESE ZONE CARBONIFEROUS Black-shales in turbiditic distal sequences (Brejeira Formation) > 2000 meters thick > km2 > 0 to 5 km deep

13 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL B) MESOZOIC UNITS LUSITANIAN BASIN Mesozoic Basin Up to 5 km thick infill (onshore) Offshore and Deep offshore areas Well-known Source-rocks Active Oil & Gas systems

14 Part I. GEOLOGICAL BACKGROUND OF PALEOZOIC AND MESOZOIC BLACK-SHALES IN PORTUGAL SOURCE-ROCKS (Overview) Lower Jurassic Marine marls and black-shales Upper Jurassic Lagoonal marly limestones Upper Cretaceous Marine marls Maturation into the Gas-window is dependent on depocenters with over 3 km thick overburden.

15 Jurassic source-rocks and oil-seeps OK! Gas? Shale-gas?

16 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET Scientific knowledge about the geological units, has been oriented towards - Stratigraphy - Sedimentology - Structural Geology Most of the PALEOZOIC units have not been characterized in terms of TOC and Maturation, because they were mostly considered metamorphic and overmature. Most of the MESOZOIC units have been characterized as Source-rocks (TOC, Maturation), but not as shale-gas units. The main relevant issues have not been addressed systematically! So, what do we realy know about Shale-gas potential in Portugal?

17 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET WHAT WE DO KNOW CIZ Silurian A) PALEOZOIC UNITS TOC? (BEICIP, 1996; Uphoff, 2005; McCOrmack et al, 2007) CIZ Carbonif. Central Portugal (CIZ) 15 TOC data from Silurian 19 TOC data from Carboniferous GOOD ORGANIC CONTENT Southern Portugal (SPZ) 19 TOC data from Carboniferous POOR TO MODERATE ORG.CONT SPZ Carbonif.

18 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET WHAT WE DO KNOW A) PALEOZOIC UNITS MATURATION? Central Portugal (CIZ) Silurian GOOD maturation (Gas-window) Carboniferous - Imature for Gas? (3 samples) Southern Portugal (SPZ) Mixed indications, from Gas-window to Overmature

19 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET WHAT WE DO KNOW B) MESOZOIC UNITS TOC? Lower Jurassic SR GOOD Organic content Higher potential towards NW Upper Jurassic SR Irregular Organic content But ALL the basin has potential LOWER Jur SR UPPER Jur SR

20 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET WHAT WE DO KNOW B) MESOZOIC UNITS MATURATION? Lower Jurassic SR Maturation to Gas-Window in South (and in NW?) Upper Jurassic SR NO Maturation to Gas-window LOWER Jur SR UPPER Jur SR

21 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET WHAT WE DON T KNOW. YET PZ - Central Portugal Are the promising TOC and Maturation values representative of regional properties? Or are they just a local feature in restricted areas? PZ - Southern Portugal Are the low TOC values and high maturation values representative of the whole Carboniferous? Or are there more promising areas, related to specific paleogeographic and structural sectors?

22 Part II. SHALE-GAS POTENTIAL - WHAT WE DO KNOW... AND WHAT WE DON T KNOW... YET WHAT WE DON T KNOW. YET MESOZOIC Are the good TOC and maturation values for the Lower Jurassic representative of a sufficiently large area? Is it possible that the Upper Jurassic SR units may be mature towards the deeper offshore areas? Is it possible that Mesozoic units may preserve gas generated from Paleozoic shale-gas units?

23 Part III. PRELIMINARY EXPLORATION ACTIVITIES IMPROVING TECHNICAL KNOWLEDGE, TO SUPPORT DECISION-MAKING A) PALEOZOIC Scientific Research Project Shale Gas Potential in Southern Portugal Partex (Portugal) + Repsol (Spain) + Universities B) MESOZOIC Exploration Project Lias Play Porto Energy (USA) + RAG (Austria) + Sorgenia (Netherlands)

24 RESEARCH PROJECT

25 Methodology Sampling & New Data (72 samples) TOC + Rock-Eval + Ro% + Gamma Ray Bibliographic Data & Infos collection ArcGIS plotting (Reflectance; TOC) Maps construction (Geological; Reflectance; TOC) Models drawing (Geological, Stratigraphic; Geodynamic) Data & Infos interpretation (TOC?; Maturation?; Gas?) Listing of Pros & Cons of the area Recommendations

26 Re-appraisal of ORGANIC GEOCHEMISTRY TOC Last samples with high TOC ROCK-EVAL Poor data regarding Kerogen Type, IH and TMax

27 Re-appraisal of MATURATION New Ro% Data + Gamma-Ray correlation Maturation may be lower than indicated by previous studies

28 OVERALL CONCLUSIONS Some new encouraging field and Lab data. Highly variable and sometimes contradictory data. Good potential of some specifica units.

29 FUTURE DEVELOPMENTS To concentrate detailed studies in the most promising Carboniferous unit in Southern Portugal To approach a preliminary characterization of Silurian units in Central Portugal, to confirm (or not) the existent good indicators

30 LIAS PLAY Unconventional Shale-gas Project Porto Energy (USA) + RAG (Austria) + Sorgenia (Netherlands)

31 LIAS PLAY Unconventional Shale-gas Project Porto Energy (USA) + RAG (Austria) + Sorgenia (Netherlands) BASEMENT TIMING PROJECT (Margins Exploration Group) - Direct observation of cuttings in wells crossing the Mesozoic infil, to the Paleozoic basement - Identification of lithologies and terranes - Modelling of Basement terranes beneath the Mesozoic basin - Indications about Shale-gas potential beneath the Mesozoic basin (sourcing into Mesozoic reservoirs? Pena dos Reis et al., 2012

32 Part III. PRELIMINARY EXPLORATION ACTIVITIES IMPROVING TECHNICAL KNOWLEDGE, TO SUPPORT DECISION-MAKING FUTURE PERSPECTIVES FOR UNCONVENTIONAL IN PORTUGAL Improve geological knowledge (TOC and Maturation; values and variability) Improve technical knowledge (physical characterization of the rocks) Develop preliminary exploratory assessments in selected areas Develop small-scale experimental production?

33 FINAL REMARKS Considering the geological conditions, it may be stated that there is Shale-gas potential in Portugal. This potential needs further scientific and technical knowledge to be assessed. Once this potential is fully assessed, experimental projects should be launched in small pilot-areas with well-known parameters. If successfull, shale-gas projects will be crucial to diminuish Portuguese critical energydependence. Public opinion is still not aware about the shale-gas issues, as much as about the oilissues. But as soon as exploration becomes active, public explanations will be needed.

34 UNCONVENTIONAL OIL & GAS POTENTIAL IN PORTUGAL Nuno PIMENTEL, LISBON UNIVERSITY Rui PENA DOS REIS, COIMBRA UNIVERSITY Thank you!