The MB-4 development well in southern Tanzania’s Mnazi Bay Concession has encountered Miocene gas reservoirs with net pay of 24 m (Upper Mnazi Bay) and 43 m (Lower Mnazi Bay) respectively, Wentworth Resources said in a news release.

The well, drilled to a total depth of 2,788 m, is located about 800 m from the MB-2 and MB-3 wells in the Mnazi Bay gas field. Wentworth has ranked the recent discoveries as being among the best of the five wells drilled in this field to date. Pressure measurements confirmed the lateral and the vertical connectivity of each reservoir, the company said in the news release.

Within this well, two reservoirs were tested at different two-hour stabilized flows with the Upper Mnazi Bay achieving a constrained flow-rate of up to 18.8 MMscf/d and the Lower Mnazi Bay of up to 22.2 MMscf/d. The table below shows the test results:

Choke (inches)

16/64

24/64

32/64

36/64

40/64

Upper Mnazi Bay

Qg (MMscf/day)

3.9

8.7

14.7

18.8

-

WHFP (bars)

173

172

167

165

-

Lower Mnazi Bay

Og (MMscf/day)

-

9.2

15.7

19.3

22.2

WHFP (bars)

-

176

171

167

163

The well will be connected to the production facilities which are currently being installed in the field, for start-up in third-quarter 2015, according to the release. These results confirm the Mnazi Bay gas field’s ability to produce output over and above the initial 80 MMscf/d, possibly up to 130 MMscf/d.

MB-4 well was deepened to the Oligocene where it encountered high-pressure intervals of unknown origin, the release said.

Wentworth has a 31.94% net interest in this well, which was operated by Maurel et Prom.