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1
TECHNICAL SUMMARY
UCAYALI BASIN
PERU
Prepared by G&G Group Exploration Management
PERUPETRO S.A.
May, 2008
2
Technical Summary Blocks 160, 161, 162 & 163 Ucayali Basin
I. INTRODUCTION The Ucayali Basin is one of the sub-Andean Basins of Peru with a prospective area of 105,000 km2 and some 5,000m of sedimentary infill. The Basin borders on the Brazilian Shield to the east and extends 650 km in length south from the Marañon Basin to the Madre de Dios Basin and 250 km in width east from the Fold Thrust Belt to beyond the Brazilian border.
The dominant structural form of the Basin is major basement-involved thrusting which in many cases is the result of reactivated Paleozoic normal faults, and along its western margin, it is one of detached thrusts along almost its entirety. The western thrust front can be divided into three segments; the northern Ucayali FTB, the Oxapampa/Ene FTB and the Camisea FTB. The first two are separated by a lateral ramp and the later two are divided by the Shira Mountains.
At present, three oilfields (Agua Caliente, Maquia and Pacaya) and six gas-condensate fields (Aguaytia, San Martin, Cashiriari, Pagoreni, Mipaya and Kinteroni) have been discovered in the Ucayali Basin. The main reservoirs in the Basin are Cretaceous continental and marine sandstones with subordinate Upper Permian lacustrine, eolian and restricted marine sandstones.
Blocks 160, 161, 162, 163 have I total 1’948,271.484 ha in size and are located in the northern part of the Ucayali Basin (Figure 1 & 1A), south and southeast of the Cushabatay High and west of the Contaya Arch.
II. EXPLORATION HISTORY The seismic available on the Blocks is a collection of older reprocessed data from the 1970’s and a more recent data set acquired in the north half of the Block 160 by Coastal in the late 1990’s. There are two oil fields, Maquia and Huaya (sub commercial) located near the northern portion of the Block 160 and one gas field, Aguaytia, in the south close to the Block 162 and 163 (Figure 2). Maquia and Huaya have oil within the Upper Cretaceous Vivian reservoirs sourced from the Pucará Formation, and Aguaytia, is a gas and condensate field producing from the Lower Cretaceous Cushabatay reservoir. The gas in Aguaytia is believed to be sourced from the Pucará although a recent study by Occidental Petroleum concludes that the gas is sourced from the Ambo Formation.
Eight Wells have been drilled on the area: Rayo 1X (El Oriente, 1947), Santa Clara 1X (Petrolera Fiscal, (1948), Coninca 1X (El Oriente, 1950), Tahuaya 1X (Mobil, 1967), Pisqui 1X (Mobil, 1967), Insaya 1X (Coastal, 1996), Orellana 1X (Coastal, 1997, Marañon Basin), Rashaya Sur 1X (Pluspetrol, 1998). The earlier wells were drilled primarily on surface structures and the 1990 series of wells were drilled on well-defined seismic prospects.
III. GEOLOGICAL AND STRUCTURAL SETTING The Blocks are located along the eastern edge of the Fold and Thrust Belt (FTB) and extends westward into the synclinal region of the Basin. The northernmost portion of the Block covers the structurally complex region between the Contaya Arch and the Cushabatay High, which separates the Ucayali from the northern Marañon Basin. The Block is dominated by two major structural trends, an older NE trend and a younger NW
3
trend. The NE trend originated in the Paleozoic as a series of normal faults that sometimes have displacements of up to 1.5 seconds TWT. Often these faults have been reactivated in a reverse sense by later Andean tectonic events. The Aguaytia gas field is associated with such a fault. The other system of faults is the NW trending Late Tertiary Quechua system, which can be divided into two groups, the high angle reverse faults of the Ucayali foreland and the thin skinned detachment faults of the FTB.
The Cretaceous stratigraphy (Figure 3 and 4) is quite uniform across the Block and is characterized by the Cushabatay to Vivian succession as found in the Marañon Basin to the north. The Lower Mesozoic sequences, the Sarayaquillo, Jurassic evaporites, Pucará, and Mitu Formations, however are quite variable. These sequences thicken considerably within the grabens developed on the faulted Paleozoic platform. Conversely this succession thins dramatically or is not present at all across the Paleozoic highs. Generally the Lower Mesozoic thickens from east to west. The Paleozoic sequences are quite uniform and their thickness depends upon the amount of erosion that has taken place beneath either the Base Mitu unconformity or the Base Cretaceous unconformity, whichever forms the top of the Paleozoic (Figure 5). The uppermost formations such as the Ene are most affected by erosional removal and consequently are typically found as isolated erosional outliers.
IV. SOURCE ROCK, RESERVOIR, SEAL, GENERATION AND MIGRATION 4.1 Source Rocks The principal source rock for the Blocks is the Pucará Formation, although the Ambo (possibly the source of gas at Aguaytia) and the Ene Formations (the source of oil in the Agua Caliente Field, 45 km southeast of the Blocks) offer the potential of secondary sources. (Figure 7)
4.2 Reservoir Rocks The primary reservoir in the southern half of the Block is anticipated to be the Cushabatay Formation and the seals, the shales of the Raya Formation. In the north, the Upper Cretaceous reservoirs as at Huaya and Maquia are also considered targets. Additionally, prospects have been defined on the Block within the Ene Formation which is productive in the Camisea Field of the southern Ucayali Basin and the Pucará Formation which tested gas in the Shanusi well of the southern Marañon Basin. Other secondary targets are the Carboniferous Copacabana carbonates and the Green Sandstone.
V. TRAPS AND EXPLORATION PLAY The prospects and leads fall into two categories on the Block, a) Foreland Structures, and c) Stratigraphic Leads. (Figure 8)
a) Foreland Structures:
From the Coninca well and northward, the Cretaceous reservoirs are completely fresh water flushed. South of this well, flushing is limited to the Agua Caliente and younger sands while the deeper Cushabatay is separated from the Agua Caliente by the Raya shales, and remains unaffected. As a result, a large number of the structures mapped in the northern regions of the Basin are probably completely flushed of hydrocarbons as evidenced by the negative well results. However, Maquia is a significant exception and an oil column is found overlying a fresh water column. This at least proves structures in this part of the Basin can be productive in spite of the flushing issue.
The Rashaya Norte prospect is located in the region where the Cushabatay is protected from flushing as evidenced by the Rashaya Sur well. This well tested high gravity crudes from the Cushabatay and also from sand stringers in the Raya Formation on a Late Tertiary NW trending structure. Updip and on a separate fault block associated with a reactivated inverted Paleozoic structure is the Rashaya Norte prospect. What makes Rashaya Norte a particularly attractive target is that it has
4
similar characteristics to the productive Aguaytia structure in that the critical closure is set up by a reactivated SW to NE trending Paleozoic fault, an inverted graben. Rashaya Sur on the other hand has characteristics similar to the unproductive NW trending Andean aged structures tested by Pisqui and Zorrillo wells.
b) Stratigraphic Leads:
Two stratigraphic leads have been identified on the Block, the Ipactia Lead and the Cushabatay South Pucará Lead (CSPL). The Ipactia lead is an Ene erosional outlier associated with an inverted Paleozoic fault. Two seismic lines define the zero edge of the Ene and the mapped Ene interval is the only occurrence of the Formation in the immediate area. The Ene is productive at Camisea and due to its rare occurrence in this area the specific lithology of the Formation at this location is unknown. A 160 to 210 meter-thick massive quartzose sandstone overlying Copacabana carbonates in wells Hualla 3X and Orellana 1X is representing a portion of Ene in this part of the basin. The second stratigraphic lead is a Pucará play that has characteristics analogous to the gas bearing porous Pucará tested by the Shanusi well in the southern Marañon Basin. The CSPL lead has the Pucará in a position in which it was deposited over a Paleozoic erosional high associated with a series of half grabens that developed on the Paleozoic surface. The concept is that high-energy carbonate deposition occurred over this high that resulted in the development of a porous carbonate similar to what was intersected in the Shanusi well. Off of the high within the paleo-half grabens, the Pucará is anticipated to have affinities associated with deeper water carbonate deposition and consequently a non-reservoir facies. This facies would then act as the updip and lateral seal to the CSPL play. The only difference between this play and the Shanusi feature is that lack of a present day structure. What makes this play attractive is that source, seal and reservoir are all self contained within the Pucará.
VI. CONCLUSIONS
• The dominant structural form of the Ucayali Basin is major basement-involved thrusting which in many cases is the result of reactivated Paleozoic normal faults, and along its western margin, it is one of detached thrusts along almost its entirety.
• It was identified eolian sandstones in San Alejandro 1X that were correlated to Permian sandstones.
• The source rocks in the area are from Jurassic, Permian and Carboniferous rocks
• 15 leads identified in the area
VII. REFERENCES 1. Parsep (2003), Ucayali/Ene Basin Technical Report. Perupetro Technical Archive
ITP22174, ITP22175, ITP22176, ITP22177, ITP22178.
2. IDEMITSU OIL AND GAS (2003), Estudio del Potencial de Hidrocarburos de la Cuenca Ucayali-Oriente del Peru Phase 2 Petroleum System in Camisea Area Subandean Basins, Peru State of Art Geochemical Approach. Perupetro Technical Archive ITP22346
3. SPT Simon Petroleum (1993), Geology-Hydrocarbon Potentail and Prospect Analyses, Ucayali Basin-Peru. Perupetro Technical Archive ITP20480, ITP20481, ITP20482.
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APPENDIX I: MINIMUM WORK PROGRAMS
Period Months Minimum Work Program
Block 160 Ucayali Basin
1st 12 Geological and Geophysical Evaluation in order to define prospective area.
Processing and interpretation of 300 km of 2D seismic and prepare a Technical Report
2nd 18 Acquisition, processing and interpretation of 300 km of 2D seismic, Gravimetry, Magnetometry over the seismic grid.
3rd 18 Drill a wildcat to 3300 m or reach Pucara Group.
4th 18 Drill a wildcat to 3300 m or reach Pucara Group.
5th 18 Drill a wildcat to 3300 m or reach Pucara Group.
Block 161 Ucayali Basin
1st 12 Geological and Geophysical Evaluation in order to define prospective area.
Processing and interpretation of 300 km of 2D seismic and prepare a Technical Report.
2nd 18 Acquisition, processing and interpretation of 300 km of 2D seismic, Gravimetry, Magnetometry over the seismic grid.
3rd 18 Drill a wildcat to 3300 m or reach Pucara Group.
4th 18 Drill a wildcat to 3300 m or reach Pucara Group.
5th 18 Drill a wildcat to 3300 m or reach Pucara Group.
Block 162 Ucayali Basin
1st 12 Geological and Geophysical Evaluation in order to define prospective area.
Processing and interpretation of 300 km of 2D seismic and prepare a Technical Report.
2nd 18 Acquisition, processing and interpretation of 300 km of 2D seismic, Gravimetry, Magnetometry over the seismic grid.
3rd 18 Drill a wildcat to 3500 m or reach Pucara Group.
4th 18 Drill a wildcat to 3500 m or reach Pucara Group.
5th 18 Drill a wildcat to 3500 m or reach Pucara Group
Block 163 Ucayali Basin
1st 12 Geological and Geophysical Evaluation in order to define prospective area.
Processing and interpretation of 300 km of 2D seismic and prepare a Technical Report
2nd 24 Acquisition, processing and interpretation of 300 km of 2D seismic, Gravimetry, Magnetometry over the seismic grid.
3rd 18 Drill a wildcat to 3500 m or reach Pucara Group.
4th 18 Drill a wildcat to 3500 m or reach Pucara Group.
5th 18 Drill a wildcat to 3500 m or reach Pucara Group.
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APPENDIX II. DATA SUMMARY IN BLOCKS 160, 161, 162 & 163
BLOCK 160484400.867 ha
SEISMIC INFORMATION 683.52 km 2D (577.96 km in SEG-Y Format)WELL INFORMATION Huaya 3X, Insaya 1XPROSPECTS AND LEADS 2 (Insaya Sur 1X, Lead A (Ipactia))
BLOCK 161491784.035 ha
SEISMIC INFORMATION 925.19 km 2D (256.04 km in SEG-Y Format)WELL INFORMATION Pisqui 1, Coninca 1, Inca 1, Coninca 2, Tahuaya 1PROSPECTS AND LEADS 3 (Pisqui, Tahuaya, Juantia)
AREA
AREA
BLOCK 162472327.198 ha
SEISMIC INFORMATION 1102.82 km 2D (291.29 km in SEG-Y Format)WELL INFORMATION Tiruntan 1XPROSPECTS AND LEADS 5( 32-2-G, 33-1-M,84-17-SN,84-16-SN,84-15-SN)
BLOCK 163499759.384 ha
SEISMIC INFORMATION 1233.72 km 2D (520.71 km in SEG-Y Format)WELL INFORMATION Aguaytia 3X, Zorrito 1, Neshuya 5
PROSPECTS AND LEADS 5(Zorrillos, Curimaná, Campo Verde, San Alejandro, 84-14-SN)
AREA
AREA
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Figure 1. Location of Block 147 in the Marañón Basin circled in blue.
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Figure 1A. Location map for the Blocks 160, 161, 162 and 163
Figure 2. Geological map of The Ucayali Basin showing the oil fields in the area.
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MARAÑON/HUALLAGA
UCAYALIGENERALIZED STRATIGRAPHIC COLUMN
OIL GAS SOURCE ROCK
MADRE de DIOS
Tectonic Events
MARAÑON/HUALLAGA
UCAYALIGENERALIZED STRATIGRAPHIC COLUMN
OIL GAS SOURCE ROCK
MADRE de DIOS
Tectonic Events
Figure 3. Generalized Stratigraphic Column for the Subandean Basins
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Figure 4. N-S Stratigraphic Cross Section in The Ucayali Basin
Figure 5. Isochron Map from Base Cretaceous to top of Cabanillas Fm over the northern area of
Ucayali Basin
RASHAYA SUR 1X
2500
3000
NESHUYA 5_1
2000
2500
3000
CONINCA 2X
1500
2000
2500
AGUAYTIA 1X
1500
2000
2500
AGUA_CAL_1
500
1000
1500
RUNUYA 1X
2000
2500
3000
3500
SEPA 1X
500
1000
1500
2000
MIPAYA 5X
1500
2000
2500
SAN MARTIN 1X
1500
2000
2500
3000
3500
-1000 -1000
-2000 -2000
-3000 -3000
-4000 -4000
Meters
S H
I R A
M O
U N
T A
I N S
C O
N T A Y A
CU S H A B A T A Y
M O U N T A I N S
F O
L D
T H
R U
S T
B E
L T
F O
L D
T H
R U
S T
B E
L T
CAMISEA
SECTION 4
Agua Caliente 1X
Aguaytia 1X
Coninca 2X
Neshuya 1X
Runuya 1X
San Martin 1X
Rashaya Sur 1X
Mipaya 1X
Sepa 1X
200 KM
SECT ION 4
TERTIARY
NOI PATSITERAYA
CUSHABATAY
SARAYAQUILLO
PUCARA
EVAPORIT ES
TARMA-COPACABANA
NW SE
GREEN SS
VIVIAN
CHONTA
AGUA CALIENTE
AMBO
BASEMENT
SHINAIENE SS
LOWER SS
MID MUDSTON E
30 KM 31 KM 43 KM 100 KM38 KM 180 KM 46 KM70 KM
DATUM
TARMA-COPACABANA
CABANILLAS ?
ANANEA ?
DEVONIAN
CABANILLAS
CONTAYA
CONTAYA
AMBO
CABANILLAS-CONTAYA
PUMAYACU
RASHAYA SUR 1X
2500
3000
NESHUYA 5_1
2000
2500
3000
CONINCA 2X
1500
2000
2500
AGUAYTIA 1X
1500
2000
2500
AGUA_CAL_1
500
1000
1500
RUNUYA 1X
2000
2500
3000
3500
SEPA 1X
500
1000
1500
2000
MIPAYA 5X
1500
2000
2500
SAN MARTIN 1X
1500
2000
2500
3000
3500
-1000 -1000
-2000 -2000
-3000 -3000
-4000 -4000
Meters
S H
I R A
M O
U N
T A
I N S
C O
N T A Y A
CU S H A B A T A Y
M O U N T A I N S
F O
L D
T H
R U
S T
B E
L T
F O
L D
T H
R U
S T
B E
L T
CAMISEA
SECTION 4
Agua Caliente 1X
Aguaytia 1X
Coninca 2X
Neshuya 1X
Runuya 1X
San Martin 1X
Rashaya Sur 1X
Mipaya 1X
Sepa 1X
200 KM
SECT ION 4
S H
I R A
M O
U N
T A
I N S
C O
N T A Y A
CU S H A B A T A Y
M O U N T A I N S
F O
L D
T H
R U
S T
B E
L T
F O
L D
T H
R U
S T
B E
L T
CAMISEA
SECTION 4
Agua Caliente 1X
Aguaytia 1X
Coninca 2X
Neshuya 1X
Runuya 1X
San Martin 1X
Rashaya Sur 1X
Mipaya 1X
Sepa 1X
200 KM200 KM
SECT ION 4
TERTIARY
NOI PATSITERAYA
CUSHABATAY
SARAYAQUILLO
PUCARA
EVAPORIT ES
TARMA-COPACABANA
NW SE
GREEN SS
VIVIAN
CHONTA
AGUA CALIENTE
AMBO
BASEMENT
SHINAIENE SS
LOWER SS
MID MUDSTON E
30 KM 31 KM 43 KM 100 KM38 KM 180 KM 46 KM70 KM
DATUM
TARMA-COPACABANA
CABANILLAS ?
ANANEA ?
DEVONIAN
CABANILLAS
CONTAYA
CONTAYA
AMBO
CABANILLAS-CONTAYA
PUMAYACU
TERTIARY
NOI PATSITERAYA
CUSHABATAY
SARAYAQUILLO
PUCARA
EVAPORIT ES
TARMA-COPACABANA
NW SE
GREEN SS
VIVIAN
CHONTA
AGUA CALIENTE
AMBO
BASEMENT
SHINAIENE SS
LOWER SS
MID MUDSTON E
30 KM 31 KM 43 KM 100 KM38 KM 180 KM 46 KM70 KM
DATUM
TARMA-COPACABANA
CABANILLAS ?
ANANEA ?
DEVONIAN
CABANILLAS
CONTAYA
CONTAYA
AMBO
CABANILLAS-CONTAYA
PUMAYACU
11
0 m
1000 m
2000 m
3000 m
4000 m
5000 m
6000 m
7000 m
8000 m
9000 m
10000 m
1000 m
SW
YAHUARANGO- VIVIAN
CHONTAAGUA CALIENTE-RAYA CUSHABATAY
SARAYAQUILLO
PUCARA(?)
SALT ANOMALY
TARMA COPACABANA
CABANILLAS
CONTAYA
G1001 CG35-61
7
G01-167
W74-20 W74-55MIG
G97 W84-6
G97 W84-5
G97 W84-5
0 m
1000 m
2000 m
3000 m
4000 m
5000 m
6000 m
7000 m
8000 m
9000 m
10000 m
1000 m
NE
AGUAYTIA 2X
TARMA- COPACABANA
CABANILLAS
CONTAYA
PUCARA
SALT ANOMALY
SARAYAQUILLO
G600 G 424
SARAYAQUILLO
SARAYAQUILLO
BASEMENT
UPPER RED BEDS
TARMA COPACABANA
CHONTA- AGUA CALIENTE
CHONTA- AGUA CALIENTE ENE
TARMA COPACABANA
Figure 6A. Regional structural cross section
Fig 6B. Location Map of the Regional W-E structural cross section (red line)
12
Figure 7. Source rocks families in The Ucayali Basin
13
Figure 8. Prospect and Lead Map in The Ucayali Basin
Figure 9. Seismic lines on the Ipactia structure. See seismic location on Fig 8