Block summary 20/11 | Page. 1

Block 20/11

Summary

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1. Generality

The Kwanza Basin is a passive margin, which origin is related to the rift that caused the

separation between South America and Africa and consequently originated the formation

of the South Atlantic. Recent discoveries in the Offshore Kwanza Basin, confirm the

existence of a functional oil system.

Block 20/11 is in deep water of the Kwanza Basin, approximately 125 Km from Luanda

(Figure 1). The Block covers an area of 4801.67 Sq Km and the water depth ranges

between 300-1500 meters

Figure 1 - Location of Block 20/11

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Block 20 database consists of 2D and 3D seismic, in time and depth, gravimetric,

magnetometric and well data. Acquisition of 5.446 Km of 2D seismic and 4.200 Sq Km of

3D seismic was performed, and 5 wells were drilled, 4 exploration (Lontra-1, Orca-1,

Zalophus-1, Golfinho-1) and 1 appraisal (Orca-2).

Figure 2 - Location of Block 20/11

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2. Block Potential

The Block has potential at the pre-salt reservoirs, in the "Sag" and "Syn-rift" sequences,

consisting mainly of carbonates, from microbiolyti and coquinas facies of Neocomian to

Aptian ages. The seal is constituted by the Loeme Formation (Salt) and the source rock are

carbonates rich in organic matter.

Drilled wells have confirmed the existence of approximately 1.9 billion barrels of oil

equivalent of recoverable resources. The block success rate is 100%.

Lontra field is a Gas and Oil (rim) Discovery. The field covers an area of 88.88 Sq Km

(Figure 3). The reservoir has high quality, which lithology is characterized by Microbiolites

and Coquinas. Lontra-1 well penetrated a hydrocarbon column of about 77 m (64 m of gas

and 13 m of oil column). The DST (Drilling Steam Test) flowed 2500 bbl/d, 39 mmscf/d,

corresponding 9000 boe/d and the API ranged from 29-50 degrees.

Figure 3 - Seismic line (Lontra)

Orca field is an Oil Discovery (Figure 4). Orca-1 well penetrated 138 m hydrocarbon

column in the Sag (27 m of gas and 111m oil column) and 56 m in the Syn-rift. In Orca-2

well the interval in the Syn-rift has a total of 150 m (65 m of gas and 85 m of oil). An API

grade of 44 and 32 was recorded for the Orca 1 and Orca 2 wells, respectively. Orca-2 well

confirmed the results of Orca 1, having 6650 bopd in the DST test post stimulation.

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Figure 4 - Seismic line (Orca)

Zalophus field is a Gas Condensate Discovery. Zalophus-1 well penetrated 475 m (MD)

from the pre-salt section, with net pay of 44 m MD. Samples were collected in 2 zones and

proved the presence of gas condensate with a density of 0.39 gm/cc and the fluid gradient

of 0.17 psi/ft. Low CO2 and an API grade of 42° were recorded.

Golfinho field is an Oil Discovery. Golfinho-1 well penetrated a total of 215 m of net gross

with a hydrocarbon column of 189 m. The reservoir has excellent quality and the API is

43.6 – 43.8°.

In terms of prospectivity, the Block has an estimated hydrocarbon potential of about 2.5

billion barrels of oil and 12 TCF of gas, distributed over several leads and prospects

(Figures 5.1 and 5.2).

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Figure 5.1 - Seismic Line (Caperea and Grenadier Prospects)

Figure 5.2 - Seismic line (Capensis Prospect)