Greater Bualuang refers to our acreage position in the Gulf of Thailand. This consists of the Bualuang oil field and the G4/50 exploration concession.

The Bualuang oil field is the Group’s flagship production asset and has been on-stream since 2008. When Salamander took over the development of the field it was thought to contain c. 14 MMbo of 2P reserves and have a productive life of approximately five years.  However, the field has undergone six reserve upgrades and it is now expected to ultimately recover c. 75 MMbo and be producing well into the next decade.  

Between 2008 and 2012 daily production averaged between 7,000 and 8,000 bopd. Following investment in an additional wellhead platform that was installed in 2012, the Atwood Mako rig was taken on long term contract and following a period of sustained development drilling in 2013 production increased 71% to average 12,300 bopd.  Further development drilling is planned during 2014 and production is expected to average between 11,000 and 14,000 bopd.

Block G4/50 covers 2,900 sq km surrounding the Bualuang production licence and contains five sub-basins. Over 60 leads and prospects have been matured and exploration drilling commenced in 2H 2013, with the Surin oil discovery, and is expected to continue in 2014.
 

Production Block B8/38 lies within the larger surrounding exploration Block G4-50 in the central part of the Western Basin geological province.

The Gulf of Thailand consists of four main Tertiary basins – Chumphon, Western, Kra and Pattani. The earliest date of basin development is Oligocene and movement along major faults initially resulted in N-S oriented grabens /half grabens. The basins are results of the collision of India with Central Asia in Eocene time which caused asymmetrical grabens and strike-slip faults with right-lateral movements, as well as en-echelon normal faults trending generally north-south. The grabens filled with non-marine to marginal marine Tertiary sediments. Underlying the graben sediments are a variety of Palaeozoic marine carbonates, granitic intrusive rocks and meta sediments. The Stratigraphy of the Western Basin comprises three main sequences: a pre-Tertiary sequence, a syn-rift sequence and a post-rift sequence.

The T2 and T3 oil bearing sands are within the syn-rift sequence. This sequence consists of Late Oligocene to Early Miocene fluvial-deltaic sands and shale. The T4 sand which is the primary producing zone in Bualuang oil field and the T5 unit which is also oil bearing are part of the post-rift sequence. This sequence consists of Mid Miocene fluvial clastics with minor marginal marine mudstone and sandstone.

The proved and probable (“2P”) reserves booked against the Bualuang oil field as at 31 December 2013 stood at 30.1 MMbo.  The field was initially thought to contain only 14 MMbo of 2P reserves and has undergone six reserves upgrades to date to take it to the 30.1 MMbo currently booked. In addition, over 17 MMbo have been produced since the field went on-stream in August 2008.

Production to date has mainly been from the T4 reservoir and this is where the majority of the 2P reserves sit. Further reserve and resource upside has been indentifed in the field following the drilling programme in 2013 and this resulted in 129% increase in contingent resources as at 31.12.13 to 27.8 MMbo.

In addtion to the main T4 reservoir which has been the focus of the majority of development activity to date, reserves or resources are now booked in the shallower T5 reservoir, the deeper T2 and T3 reservoirs and in the East Terrace.

Exploration activities in the Gulf of Thailand are centred on the G4/50 concession. G4/50 covers 5,800 sq km and surrounds the B8/38 licence (that contains the Bualuang oil field).

The Gulf of Thailand is underlain by a series of rift basins and there are five sub-basins defined within G4/50: the Western Central; Bualuang; Western South; Kra Central; and Kra South sub-basins.  There is comprehensive 3D seismic coverage on the licence and from this data over 60 leads and prospects have been identified.  The majority of the preferred leads and prospects lie within the Bualuang and Western South sub-basins.

An Environmental Impact Assessment for 20 drilling locations in the Bualuang and Western South sub-basins is going through the approval process.  

On receiving the EIA approval, an extensive exploration programme is planned with the initial targets likely to include the following prospects:

Exploration wells in G4/50 are both quick and cheap to drill, taking around 10 days and costing c. $4MM*.  Any discoveries can be brought on-stream in around 18-24 months.

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