PETROLEUM GEOLOGY AND HYDROCARBON POTENTIAL OFFSHORE URUGUAY MSc. Bruno Conti October 20 th 2017, London
Tectonic Events Falkland rifting (~175-150 Ma) Upper Jurassic Argentina/Uruguay-Namibia breakup (~142-130 Ma) Lower Cretaceous (Berriasian-Barremian) Brazil-Angola breakup (~125-112 Ma) Aptian-Albian From The Petroleum Habitats and Exploration New Frontiers in the South Atlantic Basins (pannel III) held in Montevideo, October 28 th 2013
Geodynamic context of the South Atlantic Free Air anomaly South Atlantic Major Tectonic and Structural Features Equatorial SA Central SA Segmentation of the South Atlantic: Equatorial Segment Central Segment South Segment Central Segment: Magma-poor margin Miocene volcanism Aptian evaporite basins Southern SA Compared to Magma-Poor Margins, Volcanic Margins are historically under-explored! From The Petroleum Habitats and Exploration New Frontiers in the South Atlantic Basins (pannel III) held in Montevideo, October 28th 2013 South Segment: Magma-rich margin Development of SDRs Cretaceous volcanism (oceanic ridges)
Tectonic and structural framework of the continental margin of Uruguay Three basins are recognized offshore Uruguay: Punta del Este Basin to the west Pelotas Basin to the east and Oriental del Plata Basin in ultradeep waters. In shallow waters Punta del Este and Pelotas are separeted by a basement high (Polonio high) in shallow waters.
Rio de la Plata Transfer System Bathymetry Free-aire gravity TMI Bouguer gravity anomaly
Top basement structural TWT map Two main tectonic trends: NW SE and NE SW and the distribution of extensive efforts (blue arrows) that affected the Continental Crust (Polonio High). CC: Continental Crust, TC: Transitional Crust, OC: Oceanic Crust.
Polonio High Onlap shows gradual drowning of Polonio High Clinoforms indicate NE transport of sediment along the shelf, from Miocene to Recent 0 3,5 3D structural map of basement 7
Punta del Este Basin (dip seismic line) Lobo x-1 TD: 2713 m, water depth: 42 m Gaviotin x-1 TD: 3631 m, water depth: 56 m
Lobo and Gaviotin wells Drilled by Chevron in 1976 Both declared dry wells Paleozoic sequence found in the last 139 m of Gaviotin well They did not find significant source rocks levels. An active petroleum system could not be proven. These results affected the exploration activity in the offshore of Uruguay for several years
Gas indications (Neutron-density) in Gaviotin well
Hydrocarbon evidences: Fluid inclusions in Lobo and Gaviotin cuttings Study made by FIT in 2011 The results of the new analysis indicate dry gas anomalies in each well in Jurassic, Cretaceous and Tertiary levels. Low, moderate and high gravity oil inclusions were found in 28 thin sections of sandstones and volcanic materials. Efficiency of the regional seal (deposited in the Maastrichtian- Paleocene transgression) is evident from the available data. The results demonstrate the generation of native hydrocarbons, migration pathways and the existence of paleo-hydrocarbon accumulations.
Pelotas Basin (dip seismic line) RAYA WELL (projected)
Arbitrary line showing all the wells drilled Seabed Basement
Stratigraphy
Source rock distribution PRERIFT SYNRIFT APTIAN-ALBIAN CENOMANIAN-TURONIAN
Prerift source rock
Synrift (Halfgrabens with lacustrine source rock) SE NW 4 5 6 3 km TWT SE NW 6 7 5 km TWT
Aptian source rock in seismic First marine transgression of the basin Coincident with the first oceanic anoxic event of the cretaceous (OAE1) 6,000 8,000 Aptian-Albian 10,000 Basement 10 km Km
Cenomanian-Turonian Source rock Coincident with the second oceanic anoxic event of the Cretaceous (OAE2) NW 8,000 10,000 12,000 SE
Geological model and plays A) Plays related to Pre-Cretaceous sequence (PRERIFT) B) Plays related to Synrift C) Carbonatic Plays (TRANSITION) D) Cretaceous Postrift Silicilcastic Plays E) Cenozoic Postrift Silicilcastic Plays D B C E A D D
PLAY TYPES A) Plays related to Pre-Cretaceous sequence 1 - Anticlines 2 - Faulted and Rotated blocks B) Plays related to synrift sequence 3 - Lacustrine fans 4 - Pinchouts 5 - Compaction syncline C) Carbonatic Plays 6 - Carbonatic buildup in hangingwall of halgrabens 7 - Carbonatic buildup in basement highs D) Cretaceous Postrift Silicilclastic Plays 8 - Turbidites 9 - Gentle anticlines 10 - Channels 11 - Contourites 12 - Pinchouts E) Cenozoic Postrift Silicilastic Plays 13 - Turbidites 14 - Channels
A) Plays related to Pre-Cretaceous sequence Description: Related to deep Paleozoic depocenters preserved from the prerift stage. The sequence in some areas is deformed, genereting anticlines and rotated blocks. The prerift was drilled by the Gaviotin well in Punta del Este Basin (139 meters) Source rock: Permian and Devonian marine shales Reservoir: Permian sandstones Seal: Permian shales
A) Plays related to Pre-Cretaceous sequence 3 km PLAY TYPE: 4 way closure anticline 0 SW NE 5,000 10,000 7 km Depth m
A) Plays related to Pre-Cretaceous sequence 3 km PLAY TYPE: 4 way closure anticline 0 SW Seabed NE Postrift 5,000 Prerift 10,000 7 km Depth m
Sediment depth (m) 7150 7150 Seismic Total depth (m) 7330 Seismic Volumetrics Parameter Input P90 P10 Distribution Type Prospect Code: AC4 (Morpheus) A Description: Area (km2) 120 100 145 Anticline Lognormal Gross Pay Age: Thickness (m) 345 186 Pre-cretaceous 555 Lognormal NP Geometry Probable Correction Hydrocarbon: Factor 0.75 0.7 0.8 Gas Uniform Net-to-Gross 0.4 0.2 0.6 Beta Porosity 0.06 0.02 0.12 Beta Data Sh 0.73 min Max 0.60 Comments 0.85 Source Beta RY Bg Water (m3 res/m3 depth (m) sup) 0.002 180 0.0013 180 0.0017 Seismic Normal Recovery Sediment Efficiency depth (m) 7150 0.39 7150 0.30 0.60 Seismic Beta Total depth (m) 7330 Seismic Results Output P90 P10 Mean A Parameter Area (km2) Input P90 100 P10 140 Distribution 120 Type NP A Avg. Net Area Pay Thickness (km2) (m) 102.1 120 39.0 100 183 145 Lognormal 102.1 RY HC Recovery Gross Pay Yield Thickness (m^3/km^2*m) (m) 11664754 345 3394036 186 22652231 555 Lognormal 11767508 EUR NP Estimated Geometry Ultimate Correction Recovery Factor (TCF) 0.75 5.0 0.9 0.7 10.9 0.8 Uniform 5.1 Net-to-Gross 0.4 0.2 0.6 Beta Porosity 0.06 0.02 0.12 Beta RY Sh 0.73 0.60 0.85 Beta Bg (m3 res/m3 sup) 0.002 0.0013 0.0017 Normal Recovery Efficiency 0.39 0.30 0.60 Beta Results Output P90 P10 Mean
B) Plays related to synrift sequence Description: Related to halfgrabens from the synrift stage (lacustrine fans, compaction syncline, pinchouts), particularly in Punta del Este Basin. Lobo and Gaviotin wells didn t drilled the halgraben infill (only the shoulders of halgrabens) Source rock: Lacustrine shales (Barremian) Reservoir: Barremian Sandstones (alluvial, lacustrine fans) Seal: Lacustrine shales
B) Plays related to synrift sequence PLAY TYPE: Lacustrine fan SW NE 2,000 4,000 6,000 8,000 Depth m
B) Plays related to synrift sequence PLAY TYPE: Lacustrine fan SW NE 2,000 4,000 6,000 8,000 Depth m
Sediment depth (m) 3777 4922 Sísmica Total depth (m) 4070 - Volumetrics Parameter Input P90 P10 Distribution Type A Prospect Area (km2) Code: 168 47 423 LF2 Lognormal Gross Pay Description: Thickness (m) 538 386 719Lenteja Lognormal NP Geometry Correction Age: Factor 0.45 0.4 Cretácico temprano 0.5 (Neocomiano) Uniform Probable Net-to-Gross Hydrocarbon: 0.4 0.2 0.6 Beta Porosity 0.14 0.08 0.22 Beta RY Data Sh 0.73 min Max 0.60 Observaciones 0.85 Fuente Beta FVF Water (m3 depth res/m3 (m) sup) 1.263 80 1.05 110 180 km 1.50 de la cos Sísmica Normal Recovery Sediment Efficiency depth (m) 3777 0.22 4922 0.15 0.30 Sísmica Beta Total GOR depth (scf/stb) (m) 1300 4070 340.00 2260.00 Uniform - Results Output P90 P10 Mean A Parameter Area (km2) Input P90 46 P10 349 Distribution 168 Type NP A Avg. Net Area Pay Thickness (km2) (m) 95.5 168 43.4 47 156 423 Lognormal 95.4 RY HC Recovery Gross Pay Yield Thickness (m^3/km^2*m) (m) 18520 538 8449 386 31063 719 Lognormal 18703 EUR NP Estimated Geometry Ultimate Correction Recovery Factor (MMbbls) 1868 0.45 280 0.4 4353 0.5 Uniform 1914 Net-to-Gross 0.4 0.2 0.6 Beta Porosity 0.14 0.08 0.22 Beta RY Associated ShGas (TCF) 0.73 2.4 0.60 0.2 0.85 5.9 Beta 2.5 FVF (m3 res/m3 sup) 1.263 1.05 1.50 Normal Recovery Efficiency 0.22 0.15 0.30 Beta GOR (scf/stb) 1300 340.00 2260.00 Uniform Results Output P90 P10 Mean A Area (km2) 46 349 168 NP Avg. Net Pay Thickness (m) 95.5 43.4 156 95.4 RY HC Recovery Yield (m^3/km^2*m) 18520 8449 31063 18703 EUR Estimated Ultimate Recovery (MMbbls) 1868 280 4353 1914
B) Plays related to synrift sequence 1,000 NW SE 4,000 8,000 Lacustrine shales Depth m
B) Plays related to synrift sequence PLAY TYPE: Lacustrine fan 1,000 NW Seabed SE Postrift 4,000 Amplitude anomaly Synrift 8,000 Basement epth m
B) Plays related to synrift sequence PLAY TYPE: Compaction syncline, pinchouts NW SE 3,000 6,000 9,000 Depth m
B) Plays related to synrift sequence PLAY TYPE: Compaction syncline, pinchouts NW Seabed SE 3,000 Postrift 6,000 9,000 Basement Synrift epth m
3) Carbonatic Play Related to carbonate isolated buildups from the transition sequence stage (in basement highs or hanging walls. Lobo and Gaviotin wells didn t drilled the halgraben infill (only the shoulders of halgrabens) Source rock: Barremian lacustrine shales and Aptian marine shales Reservoir: Carbonatic buildup from (Aptian-Albian age) Seal: Cretaceous marine shales
C) Carbonatic Play PLAY TYPE: Carbonatic buildup in basement high NW SE 3,000 5,000 7,000 Depth (m)
C) Carbonatic Play PLAY TYPE: Carbonatic buildup in basement high NW SE 3,000 Postrift 5,000 Basement Synrift 7,000 Depth (m)c
Sediment depth (m) 3220 3338 Sísmica Total depth (m) 4902 Sísmica Volumetrics Parameter Input P90 P10 Distribution Type A Prospect Area (km2) Code: 69 46 CB1 98 (Smith) Lognormal Gross Pay Description: Thickness (m) 174 Construcción 150 carbonática 200 del Aptiano sobre Lognormal Horst NP Geometry Correction Age: Factor 0.9 0.85 0.95 Aptiana Uniform Probable Net-to-Gross Hydrocarbon: 0.4 0.2 0.6 Petróleo Beta Porosity 0.10 0.05 0.15 Beta Data Sh 0.73 min Max 0.60 Observaciones 0.85 Fuente Beta RY FVF (m3 res/m3 sup) 1.263 1.05 1.50 Normal Water depth (m) 1564 1682 230 km de la cos Sísmica Recovery Efficiency 0.22 0.15 0.30 Beta Sediment depth (m) 3220 3338 Sísmica Total GOR depth (scf/stb) (m) 1300 4902 340.00 2260.00 Sísmica Uniform Results Output P90 P10 Mean A Parameter Area (km2) Input P90 46 P10 95 Distribution 69 Type NP A Avg. Net Area Pay Thickness (km2) (m) 61.9 69 30.8 46 95 98 Lognormal 61.8 RY HC Recovery Gross Pay Yield Thickness (m^3/km^2*m) (m) 12247 174 5423 150 21094 200 Lognormal 12420 EUR NP Estimated Geometry Ultimate Correction Recovery Factor (MMbbls) 326 0.9 0.85 95 0.95 652 Uniform 331 Net-to-Gross 0.4 0.2 0.6 Beta Porosity 0.10 0.05 0.15 Beta Associated Sh Gas (TCF) 0.73 0.4 0.60 0.1 0.85 1.0 Beta 0.4 RY FVF (m3 res/m3 sup) 1.263 1.05 1.50 Normal Recovery Efficiency 0.22 0.15 0.30 Beta GOR (scf/stb) 1300 340.00 2260.00 Uniform Results Output P90 P10 Mean A Area (km2) 46 95 69 NP Avg. Net Pay Thickness (m) 61.9 30.8 95 61.8 RY HC Recovery Yield (m^3/km^2*m) 12247 5423 21094 12420 EUR Estimated Ultimate Recovery (MMbbls) 326 95 652 331
C) Carbonatic Play PLAY TYPE: Carbonatic buildup in basement high 3,000 NW SE 6,000 9,000 Depth (m)
C) Carbonatic Play ANALOGY: Schematic stratigraphic model for presalt in Kwanza Basin. Saller et al. 2016 3,000 NW PLAY TYPE: Carbonatic buildup in basement high Seabed SE Cenozoic postrift 6,000 Cretaceous postrift 9,000 Aptian source rock Depth (m)
C) Carbonatic Play PLAY TYPE: Carbonatic buildup associated to halfgraben fault NW SE 5,000 7,000 Depth (m)
C) Carbonatic Play PLAY TYPE: Carbonatic buildup associated to halfgraben fault NW SE 5,000 7,000 Depth (m)
D) Cretaceous Postrift silicilastic Play Description: Stratigraphic (channels, turbidites, pinchouts, contourites) and structural (gentle anticlines) traps distributed troughout the cretaceous sequence. Not tested Source rock: Marine aptian and Turonian shales (First and Second Oceanic Anoxic Event of the Cretaceous OAE1-OAE2) Reservoir: Conician, Santonian, Maastritichian sandstones Seal: Shales of the Paleocene transgression
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Turbidites, pinchouts and gentle anticles 2,000 NW SE 4,000 6,000 8,000 Depth m
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Turbidites, pinchouts and gentle anticles 2,000 NW Postrift Seabed SE 4,000 Turbidite 6,000 Synrift 8,000 Basement Depth m
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Basin floor fan covered by prograding shelf NW SE
D) Cretaceous Postrift silicilastic Play Marlim field - Campos Basin, Brazil PLAY TYPE: Basin floor fan covered by prograding shelf NW SE
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Channel systems NW SE
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Channel systems NW SE Seabed
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Channel system ( Gullwing feature) NW SE
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Channel system ( Gullwing geometry) NW SE Tahoe field, GOM (Medeiros 1997)
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Pinchouts against Polonio High NW SE
D) Cretaceous Postrift silicilastic Play PLAY TYPE: Pinchouts against Polonio High NW SE
2 km D) Cretaceous Postrift silicilastic Play PLAY TYPE: Conturites and turbidites 1,000 SW NE 4,000 8,000 Depth (m)
2 km D) Cretaceous Postrift silicilastic Play PLAY TYPE: Turbidites and contourites 1,000 SW Seabed NE Cenozoic Postrift 4,000 Clastic traps Cretaceous Postrift Carbonatic? 8,000 Basement Depth (m)
E) Cenozoic Postrift silicilastic Play Description: Stratigraphic (channels and turbidites). Tested by Raya well Source rock: Marine aptian and Turonian shales (First and Second Oceanic Anoxic Event of the Cretaceous OAE1-OAE2) Reservoir: Paleocene, Eocene and Oligocene sandstones Seal: Shales of Paleocene and Miocene transgressions K/T structural map
1 s NW E) Cenozoic Postrift silicilastic Play Seabed SE 2.0 Cenozoic Postrift PLAY TYPE: Turbidites (Lower Paleocene) 4.0 Cretaceous Postrift 6.0 Basement Time (s) 9 km
E) Cenozoic Postrift silicilastic Play PLAY TYPE: Turbidites (Lower Paleocene) NW SE High amplitudes (A ) 4.0 High amplitudes (B ) High amplitudes (C) 5.0 Channel Time (s)
E) Cenozoic Postrift silicilastic Play PLAY TYPE: Turbidites (Lower Paleocene) NW SE 4.0 5.0 Time (s)
Total depth (m) Volumetrics Sísmica Parameter Input P90 P10 Distribution Type A Prospect Area (km2) Code: 111 29 SF5 287(Esmeralda) Lognormal Gross Pay Description: Thickness (m) 242 170 Abanico submarino 335 al pie del paleotalud Lognormal NP Geometry Correction Age: Factor Probable Net-to-Gross Hydrocarbon: 0.55 0.4 0.5 0.2 terciario 0.6 (paleoceno) 0.6Petróleo Uniform Beta Porosity 0.15 0.08 0.24 Beta RY Sh 0.73 0.60 0.85 Beta FVF (m3 Data res/m3 sup) 1.263 min Max 1.05 Observaciones 1.50 Fuente Normal Recovery Water depth Efficiency (m) 1270 0.22 1420 0.15 282 km 0.30 de la cos Sísmica Beta Sediment GOR (scf/stb) depth (m) 1300 4340 340.00 4370 2260.00 Sísmica Uniform Total depth (m) 4902 Sísmica Results Output P90 P10 Mean A Area (km2) 28 235 111 NP Avg. Net Parameter Pay Thickness (m) Input 52.5 23.8 P90 P10 87 Distribution 52.6 Type RY A HC Recovery Area Yield (km2) (m^3/km^2*m) 19655 111 8515 29 33080 287 Lognormal 19612 EUR Estimated Gross Ultimate Pay Thickness Recovery (m) (MMbbls) 719 242 170 98 1662 335 Lognormal 718 NP Geometry Correction Factor 0.55 0.5 0.6 Uniform Net-to-Gross 0.4 0.2 0.6 Beta Associated Porosity Gas (TCF) 0.15 0.9 0.08 0.1 0.24 2.2 Beta 0.9 RY Sh 0.73 0.60 0.85 Beta FVF (m3 res/m3 sup) 1.263 1.05 1.50 Normal Recovery Efficiency 0.22 0.15 0.30 Beta GOR (scf/stb) 1300 340.00 2260.00 Uniform Results Output P90 P10 Mean A Area (km2) 28 235 111 NP Avg. Net Pay Thickness (m) 52.5 23.8 87 52.6 RY HC Recovery Yield (m^3/km^2*m) 19655 8515 33080 19612 4902
E) Cenozoic Postrift silicilastic Play PLAY TYPE: Turbidites (Oligocene) NW SE 4,000 6,000 8,000 Depth (m)
E) Cenozoic Postrift silicilastic Play PLAY TYPE: Turbidites (Oligocene) NW Projected Raya Well SE 4,000 6,000 K-T boundary 8,000 Aptian source rock SDRs Basement Depth (m)
Final remarks Only 3 exploratory wells drilled in an area of more than 120,000 km 2 Two wells located in the proximal segment of the basin (Lobo and Gaviotin) showed several evidences of an active petroleum system (fluid inclusions and gas crossovers) Raya well didn t reach the Cretaceous sequence (the most prospective) Presence of world class source rocks (Aptian-Turonian), good quality reservoirs Development of an effective regional seal (Paleocene), proven by well data, especially in the distal segment Many prospects identified through 2D and 3D seismic in shallow, deep and ultradeep waters
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