Tatu Structure

Success from the first well

Eromanga's first exploration well on Block 430 encountered oil and was completed as a future producer in September 2008. The well was declared a discovery and re-named Tatu 1.

In 2009 the Joint Venture drilled a second well on the block. This was also declared a discovery an re-named Tatu 2.

The Joint Venture estimates a mid case Contingent Resource of 48 million Barrels oil in place with a high case of 107 million Barrels. It expects to be able to book reserves for this discovery based on the results of the extended flow tests of Tatu 1 and 2 which are planned for early 2010.

Eromanga holds 40% of the concession agreement for Block 430 with the operator Tarmar holding the remaining 60%.

Good Location

Block 430 is adjacent to two Petrobras producing fields:

Angelim field which has been in production since the 1970s and is ring fenced into Block 430; and
Carmopolis field which had +1.4 billion barrels original oil in place and has been in production since the 1960s. It is approximately 14km from well 1-NORD-1-SE

Low risk exploration

Block 430 is partly covered by an existing 3D seismic survey and also has 2D surveys with good well control.

The Joint Venture drilled its first exploration well at Block 430 in March 2008. This well had oil indications over a total interval of 143m including shows in three different reservoir types: Upper Carbonates (Zone CCC), Middle Carbonates and Fractured Basement. In the neighbouring field, Petrobras produces from all three intervals.

The Joint Venture successfully flow tested the discovery well and the Upper Carbonate section was completed as a future producer. Flow tests produced good quality light oil of 26 to 28 degrees API from the Upper carbonates with a negligible water cut.

The Joint Venture drilled the Tatu 2 well in October 2009. The well was declared a discovery with over 168 meters of oil shows.

Contingent Resource Estimate for Tatu Structure - Block 430

		Deterministic (mmBbl) (Note 1)
			3C	2C
Tatu 1 Zone CCC (Completed for production Sept 08)			37	18
Other Zones (Basement & Middle Carbonates)			70	30

Total Original Oil in Place			107	48
Total Recoverable			32	10

ERH Share of OOIP:	40%		43	19

Notes to Table 2:

1. Deterministic parameters from drilling and logging of Nord-1, the existing 3D seismic survey over part of the block and the
Joint Venture’s understanding of production from neighbouring fields

2. Definitions are in accordance with the Society of Petroleum Engineers, Petroleum Resource Management System.
Resources are defined as “Contingent” since the evaluation of the field is not sufficiently advanced at this stage to
clearly confirm commerciality.

3. The 2C and 3C values provide the range of uncertainty for potentially recoverable volumes. 2C corresponds to a 50%
probability that quantities will equal or exceed the value in the table. 3C indicates a 10% probability that the volume will be exceeded.

Block 430 was released during the ANP's 7th Round and awarded on the 12 th January 2006 to Tarmar Terminais Aero-Rodo-Marítimos Ltda ("Tarmar") a wholly owned subsidiary of UBX Ltda, Eromanga's joint venture partner in the Gavea Joint Venture. Tarmar holds a 60% interest in the Concession and is operator.