Block 4

=Overview= Block 4 is located in the Mafia Deep Basin off-shore from the Rovuma and Rufiji deltas with water depths ranging from 100 to 3,000 metres. It is operated by BG Group with a 60% working interest; Ophir Energy and Pavillion Energy both hold a 20% stake each. So far, three discoveries have been made in the block: Pweza and Chewa in 2010 and Ngisi in 2013.

=Chronology=
 * In April 2006, Block 4 was directly awarded to Ophir Energy by the Government of Tanzania.


 * In May 2010, Ophir Energy farmed down a 60% stake and operatorship to the BG Group.


 * In October 2010, the partners announced the first discovery in the block. The discovery was made in the Pweza-1 exploration well and encountered a thick section of gas bearing sands. The well is located 85km from the coastline in 1,400m depth of water.


 * In December 2010, a second discovery was announced. The discovery was made in the Chewa-1 exploration well, which is located some 80km from the coastline in 1,315m water depth.


 * In July 2013, the partnership announced the positive results of its Ngisi drilling programme and thus upgraded the recoverable resources across the Chewa-Pweza-Ngisi hub in the block to 4.5 TCF. The Ngisi-1 well was drilled 5km to the North East of the Chewa-1 well.


 * In August 2014, the successful completion of the Pweza-2 appraisal well was announced. The well was drilled 2km to the south of the Pweza-1 discovery well. The result firmed up the resource estimates for the Pweza field at 1.7 TCF of the gross recoverable resource.


 * In October 2013, BG and Ophir announced the successful completion of the Pweza-3 appraisal well and flow test. The well was drilled some 2km north of the original Pweza discovery well. A Drill Stem Test confirmed that the Tertiary reservoirs in Block 4 have similar characteristics to those in Block 1.


 * In 2013, GAIL India and Pavillion Energy bid to acquire stakes in blocks 1, 3 and 4. In December, Pavillion Energy announced that it had entered an agreement to purchase 20 per cent interest in Blocks 1, 3 and 4 from Ophir Energy for a consideration of USD 1.288 billion.



=References=